Omron hostlinkunit

Cat.No. W143–E1–6
Host Link Units
SYSMAC
C-series Rack PCs
SYSMAC WAY
SYSTEM MANUAL

SYSMAC WAY
Host Link Units
For Use With C-series Rack PCs
Revised February 2000

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v
Notice:
OMRON products are manufactured for use according to proper procedures by a qualified operator
and only for the purposes described in this manual.
The following conventions are used to indicate and classify precautions in this manual. Always heed
the information provided with them. Failure to heed precautions can result in injury to people or dam-
age to the product.
DANGER Indicates an imminently hazardous situation which, if not avoided, will result in death or
serious injury.
WARNING Indicates a potentially hazardous situation which, if not avoided, could result in death or
serious injury.
Caution Indicates a potentially hazardous situation which, if not avoided, may result in minor or
moderate injury, or property damage.
OMRON Product References
All OMRON products are capitalized in this manual. The word “Unit” is also capitalized when it refers
to an OMRON product, regardless of whether or not it appears in the proper name of the product.
The abbreviation “Ch,” which appears in some displays and on some OMRON products, often means
“word” and is abbreviated “Wd” in documentation in this sense.
The abbreviation “PLC” means Programmable Controller (Programmable Logic Controller) and is not
used as an abbreviation for anything else.
Visual Aids
The following headings appear in the left column of the manual to help you locate different types of
information.
Note Indicates information of particular interest for efficient and convenient operation
of the product.
1, 2, 3... 1. Indicates lists of one sort or another, such as procedures, checklists, etc.
 OMRON, 1990
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any
form, or by any means, mechanical, electronic, photocopying, recording, or otherwise, without the prior written permis-
sion of OMRON.
No patent liability is assumed with respect to the use of the information contained herein. Moreover, because OMRON is
constantly striving to improve its high-quality products, the information contained in this manual is subject to change
without notice. Every precaution has been taken in the preparation of this manual. Nevertheless, OMRON assumes no
responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the informa-
tion contained in this publication.

TABLE OF CONTENTS
vii
PRECAUTIONS xi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Intended Audience xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 General Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Safety Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operating Environment Precautions xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Application Precautions xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 1
Introduction 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1 Applicable Units 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2 System Configuration 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3 Mounting Host Link Units 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4 Host Computer Settings 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5 Types of Interfaces 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6 Wiring RS-232C and RS-422 Cable Connectors 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 2
Host Link Unit Characteristics 23. . . . . . . . . . . . . . . . . . . . .
2-1 C200H Host Link Units 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2 C500 (3G2A5) Host Link Units 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4 Installing and Removing Host Link Units 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3
Programming 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1 Command Levels 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2 Communications Protocol 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3 Communications Protocol (C200HS/HX/HG/HE only) 67. . . . . . . . . . . . . . . . . . . . . . . . . .
3-4 Frame Checksum (FCS) Calculation 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4
Commands and Responses 71. . . . . . . . . . . . . . . . . . . . . . . .
4-1 TEST 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 STATUS READ 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 ERROR READ 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4 IR AREA READ 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-5 HR AREA READ 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-6 AR AREA READ 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-7 LR AREA READ 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-8 TC STATUS READ 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-9 DM AREA READ 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-10 FM INDEX READ 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-11 FM DATA READ 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-12 PV READ 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-13 SV READ 1 78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-14 SV READ 2 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-15 SV READ 3 80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-16 STATUS WRITE 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-17 IR AREA WRITE 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-18 HR AREA WRITE 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-19 AR AREA WRITE 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-20 LR AREA WRITE 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TABLE OF CONTENTS
viii
4-21 TC STATUS WRITE 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-22 DM AREA WRITE 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-23 FM AREA WRITE 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-24 PV WRITE 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-25 SV CHANGE 1 85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-26 SV CHANGE 2 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-27 SV CHANGE 3 87. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-28 FORCED SET 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-29 FORCED RESET 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-30 MULTIPLE FORCED SET/RESET 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-31 MULTIPLE FORCED SET/RESET STATUS READ 90. . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-32 FORCED SET/RESET CANCEL 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-33 PC MODEL READ 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-34 DM HIGH-SPEED READ 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-35 ABORT and INITIALIZE 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-36 TRANSMIT (C200HS/HX/HG/HE only) 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-37 Response to an Undefined Command 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-38 Response Indicating an Unprocessed Command 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-39 PROGRAM READ 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-40 I/O TABLE READ 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-41 PROGRAM WRITE 94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-42 I/O TABLE GENERATE 94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-43 I/O REGISTER 95. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-44 I/O READ 96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-45 Response Code List 97. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-46 Communications Examples 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 5
Error Processing 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-1 Development of an Error-processing Program 102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2 Error Control 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-3 Example Host Computer Program 104. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-4 Troubleshooting 105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendices
A Standard Models 107. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B Specifications 111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C ASCII Conversions 123. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D Data Conversion Table 125. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary 127. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Revision History 149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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About this Manual:
This manual describes the functions, characteristics, and operating procedures of the Host Link Units
for the C-series building block PCs (Programmable Controllers), i.e., the C120, C200H, C200HS,
C200HX, C200HG, C200HE, C500, C1000H, and C2000H Units.
Section 1 gives a brief overview of the applicable Units and how to connect them into a PC system,
including the settings for the host computer. It also gives details on various interface connections and
how to prepare cables for RS-422 and RS-232C connectors.
Section 2 gives the characteristics of the different Host Link Units which are grouped according to
their model numbers. The information includes their external appearance, the names of the switches
and the functions, the PC operating modes for the various settings, flags, and I/O response times.
Section 3 gives the basics necessary for effective programming. It starts with the full set of instruc-
tions and the command levels at which they operate. Communications protocols are outlined, and the
methods for calculating the Frame Checksum (FCS) values is explained.
Section 4 provides the commands and responses for the complete set of instructions covered in this
manual. It also includes a table of error response codes and communications examples using some
of the instructions.
Section 5 details ways of detecting, preventing, and remedying errors that occur in the Host Link sys-
tems.
Appendix A provides information on the standard Host Link Unit and Link Adapter models that are
discussed in this manual and gives details for accessories that can be used with the Host Link Units,
such as connector cables and optical fiber interfaces.
Appendix B gives specifications for the Host Link Units and Link Adapters.
Appendix C provides data conversions between ASCII characters and their hex, binary, and decimal
equivalents. It should be noted that the PC always stores ASCII data in its hexadecimal equivalent.
Appendix D lists the data equivalent for hex, binary, BCD, and decimal up to 32dec.
The Glossary gives a comprehensive list of expressions commonly used when dealing with Host Link
Units and Programmable Controllers.
WARNING Failure to read and understand the information provided in this manual may result in
personal injury or death, damage to the product, or product failure. Please read each
section in its entirety and be sure you understand the information provided in the section
and related sections before attempting any of the procedures or operations given.
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PRECAUTIONS
This section provides general precautions for using the Programmable Controller (PC) and related devices.
The information contained in this section is important for the safe and reliable application of the PC. You must read
this section and understand the information contained before attempting to set up or operate a PC system.
1 Intended Audience xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 General Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Safety Precautions xii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operating Environment Precautions xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Application Precautions xiii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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5Application Precautions
xii
1 Intended Audience
This manual is intended for the following personnel, who must also have knowl-
edge of electrical systems (an electrical engineer or the equivalent).
• Personnel in charge of installing FA systems.
• Personnel in charge of designing FA systems.
• Personnel in charge of managing FA systems and facilities.
2 General Precautions
The user must operate the product according to the performance specifications
described in the operation manuals.
Before using the product under conditions which are not described in the manual
or applying the product to nuclear control systems, railroad systems, aviation
systems, vehicles, combustion systems, medical equipment, amusement
machines, safety equipment, and other systems, machines, and equipment that
may have a serious influence on lives and property if used improperly, consult
your OMRON representative.
Make sure that the ratings and performance characteristics of the product are
sufficient for the systems, machines, and equipment, and be sure to provide the
systems, machines, and equipment with double safety mechanisms.
This manual provides information for programming and operating OMRON PCs.
Be sure to read this manual before attempting to use the software and keep this
manual close at hand for reference during operation.
WARNING It is extremely important that a PC and all PC Units be used for the specified
purpose and under the specified conditions, especially in applications that can
directly or indirectly affect human life. You must consult with your OMRON
representative before applying a PC System to the abovementioned
applications.
3 Safety Precautions
WARNING Do not attempt to take any Unit apart while the power is being supplied. Doing so
may result in electric shock.
WARNING Do not touch any of the terminals or terminal blocks while the power is being
supplied. Doing so may result in electric shock.
WARNING Provide safety measures in external circuits (i.e., not in the Programmable
Controller), including the following items, to ensure safety in the system if an
abnormality occurs due to malfunction of the PC or another external factor
affecting the PC operation. Not doing so may result in serious accidents.
• Emergency stop circuits, interlock circuits, limit circuits, and similar safety
measures must be provided in external control circuits.
• The PC will turn OFF all outputs when its self-diagnosis function detects any
error or when a severe failure alarm (FALS) instruction is executed. As a coun-
termeasure for such errors, external safety measures must be provided to en-
sure safety in the system.
• The PC outputs may remain ON or OFF due to deposition or burning of the
output relays or destruction of the output transistors. As a countermeasure for

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xiii
such problems, external safety measures must be provided to ensure safety in
the system.
• When the 24-VDC output (service power supply to the PC) is overloaded or
short-circuited, the voltage may drop and result in the outputs being turned
OFF. As a countermeasure for such problems, external safety measures must
be provided to ensure safety in the system.
Caution Execute online edit only after confirming that no adverse effects will be caused
by extending the cycle time. Otherwise, the input signals may not be readable.
Caution Confirm safety at the destination node before transferring a program to another
node or changing contents of the I/O memory area. Doing either of these without
confirming safety may result in injury.
Caution Tighten the screws on the terminal block of the AC Power Supply Unit to the
torque specified in the operation manual. The loose screws may result in burning
or malfunction.
4 Operating Environment Precautions
Caution Do not operate the control system in the following locations:
• Locations subject to direct sunlight.
• Locations subject to temperatures or humidity outside the range specified in
the specifications.
• Locations subject to condensation as the result of severe changes in tempera-
ture.
• Locations subject to corrosive or flammable gases.
• Locations subject to dust (especially iron dust) or salts.
• Locations subject to exposure to water, oil, or chemicals.
• Locations subject to shock or vibration.
Caution Take appropriate and sufficient countermeasures when installing systems in the
following locations:
• Locations subject to static electricity or other forms of noise.
• Locations subject to strong electromagnetic fields.
• Locations subject to possible exposure to radioactivity.
• Locations close to power supplies.
Caution The operating environment of the PC system can have a large effect on the lon-
gevity and reliability of the system. Improper operating environments can lead to
malfunction, failure, and other unforeseeable problems with the PC system. Be
sure that the operating environment is within the specified conditions at installa-
tion and remains within the specified conditions during the life of the system.
5 Application Precautions
Observe the following precautions when using the PC system.
WARNING Always heed these precautions. Failure to abide by the following precautions
could lead to serious or possibly fatal injury.

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xiv
• Always ground the system to 100 Ω or less when installing the Units. Not con-
necting to a ground of 100 Ω or less may result in electric shock.
• Always turn OFF the power supply to the PC before attempting any of the fol-
lowing. Not turning OFF the power supply may result in malfunction or electric
shock.
• Mounting or dismounting I/O Units, CPU Units, Memory Units, or any other
Units.
• Assembling the Units.
• Setting DIP switches or rotary switches.
• Connecting cables or wiring the system.
• Connecting or disconnecting the connectors.
Caution Failure to abide by the following precautions could lead to faulty operation of the
PC or the system, or could damage the PC or PC Units. Always heed these pre-
cautions.
• Fail-safe measures must be taken by the customer to ensure safety in the
event of incorrect, missing, or abnormal signals caused by broken signal lines,
momentary power interruptions, or other causes.
• Always use the power supply voltages specified in this manual. An incorrect
voltage may result in malfunction or burning.
• Take appropriate measures to ensure that the specified power with the rated
voltage and frequency is supplied. Be particularly careful in places where the
power supply is unstable. An incorrect power supply may result in malfunction.
• Install external breakers and take other safety measures against short-circuit-
ing in external wiring. Insufficient safety measures against short-circuiting may
result in burning.
• Do not apply voltages to the Input Units in excess of the rated input voltage.
Excess voltages may result in burning.
• Do not apply voltages or connect loads to the Output Units in excess of the
maximum switching capacity. Excess voltage or loads may result in burning.
• Disconnect the functional ground terminal when performing withstand voltage
tests. Not disconnecting the functional ground terminal may result in burning.
• Be sure that all the mounting screws, terminal screws, and cable connector
screws are tightened to the torque specified in this manual. Incorrect tighten-
ing torque may result in malfunction.
• Leave the label attached to the Unit when wiring. Removing the label may re-
sult in malfunction if foreign matter enters the Unit.
• Remove the label after the completion of wiring to ensure proper heat dissipa-
tion. Leaving the label attached may result in malfunction.
• Double-check all wiring and switch settings before turning ON the power sup-
ply. Incorrect wiring may result in burning.
• Wire correctly. Incorrect wiring may result in burning.
• Mount Units only after checking terminal blocks and connectors completely.
• Be sure that the terminal blocks, Memory Units, expansion cables, and other
items with locking devices are properly locked into place. Improper locking
may result in malfunction.
• Check the user program for proper execution before actually running it on the
Unit. Not checking the program may result in an unexpected operation.
• Confirm that no adverse effect will occur in the system before attempting any of
the following. Not doing so may result in an unexpected operation.
• Changing the operating mode of the PC.

xv
• Force-setting/force-resetting any bit in memory.
• Changing the present value of any word or any set value in memory.
• Resume operation only after transferring to the new CPU Unit the contents of
the DM Area, HR Area, and other data required for resuming operation. Not
doing so may result in an unexpected operation.
• Do not pull on the cables or bend the cables beyond their natural limit. Doing
either of these may break the cables.
• Do not place objects on top of the cables or other wiring lines. Doing so may
break the cables.
• Use crimp terminals for wiring. Do not connect bare stranded wires directly to
terminals. Connection of bare stranded wires may result in burning.
• When replacing parts, be sure to confirm that the rating of a new part is correct.
Not doing so may result in malfunction or burning.
• Before touching a Unit, be sure to first touch a grounded metallic object in order
to discharge any static built-up. Not doing so may result in malfunction or dam-
age.

1
SECTION 1
Introduction
This document is designed to introduce the reader to the principles of operation of Host Link Units, their characteristics, and
methods of interfacing them into PC networks. 1-1 Applicable Units lists the PCs that are applicable for each Unit and the type
of connections which can be used.
1-1 Applicable Units 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2 System Configuration 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2-1 Connections 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2-2 System Examples 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3 Mounting Host Link Units 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4 Host Computer Settings 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5 Types of Interfaces 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5-1 Optical Interface 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5-2 RS-232C Interface 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5-3 RS-422 Interface 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6 Wiring RS-232C and RS-422 Cable Connectors 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6-1 Preparation for Connecting Shielded Cable to FG 15. . . . . . . . . . . . . . . . . . . . . . . .
1-6-2 Preparation for Connecting Unshielded Cable to FG 16. . . . . . . . . . . . . . . . . . . . . .
1-6-3 FG Connection to the Cable’s Shield Wire (RS-422 Interface) 17. . . . . . . . . . . . . .
1-6-4 Wiring 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2
1-1 Applicable Units
A Host Link Unit allows a host computer to monitor the operating status and data
areas of the PCs and to control the communications between the PCs and the
controlled system.
One Host Link Unit is required for each PC, and up to 32 PCs can be connected
to a single host computer. The Host Link Units described in this manual are re-
ferred to as “Rack-mounting” or “CPU mounting.” A Rack-mounting Host Link
Unit is mounted to an I/O slot of the CPU or Expansion I/O Rack of the building
block PC. A CPU-mounting Host Link Unit is mounted directly to the PC’s CPU.
Different types of Host Link Units, e.g., Rack-mounting and CPU-mounting, can
be combined so that the same PC can be connected to more than one Host Link
Unit. An example of a system using some of these combinations is provided in
1-2 System Configuration, along with other example configurations. Most of
these systems also employ Link Adapters, which are usually used in a system to
branch between Host Link Units, host computers, etc., or to interface wire cables
with optical fiber cables, or to perform both of these functions.
The following table gives the mounting method, types of connectors, and appli-
cable PCs for each of the Host Link Units dealt with in this manual.
Host Link Unit Mounting Type Applicable PCs Connection*
C200H-LK101-PV1*** Rack-mounting C200H, C200HS, C200HX, C200HG,
and C200HE
APF/PCF/H-PCF
C200H-LK201-V1*** Rack-mounting C200H, C200HS, C200HX, C200HG,
and C200HE
RS-232C
C200H-LK202-V1*** Rack-mounting C200H, C200HS, C200HX, C200HG,
and C200HE
RS-422
3G2A5-LK101-PEV1 Rack-mounting C500, C1000H, and C2000H APF/PCF/H-PCF
C500-LK103-P** Rack-mounting C500, C1000H, and C2000H APF/PCF/H-PCF
3G2A5-LK101-EV1 Rack-mounting C500, C1000H, and C2000H PCF/H-PCF
3G2A5-LK201-EV1 Rack-mounting C500, C1000H, and C2000H RS-232C/RS-422
C500-LK103** Rack-mounting C500, C1000H, and C2000H PCF/H-PCF
C500-LK203** Rack-mounting C500, C1000H, and C2000H RS-232C/RS-422
3G2A6-LK101-PEV1 CPU-mounting CjjH (V1 models), C200H, C120,
C500, C1000H, and C2000H
APF/PCF/H-PCF
3G2A6-LK101-EV1 CPU-mounting CjjH (V1 models), C200H, C120,
C500, C1000H, and C2000H
PCF/H-PCF
C500, C1000H, and C2000H
RS-232C
C500, C1000H, and C2000H
RS-422
* APF: All-plastic optical fiber cable/PCF: Plastic-clad optical fiber cable/H-PCF: Hard-clad plastic optical fiber cable/
RS-422: RS-422 cable/RS-232C: RS-232C cable
** The C500-LK103(-P) and C500-LK203 can be used with the C500 PC only when the 3G2C3-CPU11-EV1 is used.
*** Reading or writing words in the portion of the EM area expanded by the C200HX/C200HG/C200HE is not possible.
1-2 System Configuration
The following examples illustrate possible applications of Host Link Units in
wired or optical systems, or both.
Some systems will comprise just one Host Link Unit connected to a single host
computer. This is known as a “single-link” system. Others systems might com-
prise many Host Link Units connected to a host computer. This configuration is
known as a “multiple-link” system. Although most systems will require only one
host computer, if both Rack-mounting and CPU-mounting Host Link Units are
System Configuration Section 1-2

3
used together, two host computers can be connected to the same PC, indepen-
dent of each other. The PC can then execute commands sent from either host
computer.
Up to two of the C500-LK103, C500-LK103-P, and C500-LK203 Rack-mounting
Host Link Units can also be connected, in any combination (including two of the
same Units), to any to a single C1000H, or C2000H PC, allowing up to three host
computers to be connected to these PCs. Control from three host computers is
also available with C200H/HS/HX/HG/HE PCs, where a second Rack-mounting
Host Link Unit can be added on a C200H Expansion I/O Rack. All other PCs are
limited to two Host Link Units. SYSMAC NET Link Units can be combined with
the C500-LK103(-P) and C500-LK203 Rack-mounting Host Link Units when a
C1000H or C2000H PC is used. When combining with a SYSMAC NET Link
Unit, however, only one Rack-mounting Host Link Unit can be used instead of
two.
In all but the third configuration example, Link Adapters are used to branch be-
tween system devices, or to convert between different types of cables, or to per-
form both of these functions. The first part of the Link Adapter model numbers
(3G2A9-) in the examples has been omitted.
1-2-1 Connections
System components can be connected using RS-232C or RS-422 cables, or
both, any of three types of optical fiber cable, or a combination of wired and opti-
cal sections. In any system, the maximum length of RS-232C cable is 15 m. The
total length of all RS-422 cable must be no longer than 10 m. RS-232C and
RS-422 cables which are used to connect the Host Link Unit to the host comput-
er are not available from OMRON and must be purchased from an alternative
source.
Maximum lengths for optical fiber cables are determined by the type of cable and
the particular models employed. Models which finish with “-P” in the code num-
ber can be set at a length of 20 m for APF cable and 200 m for PCF cable. Models
without the “-P” coding can be set at a maximum length of 800m with PCF cable.
1-2-2 System Examples
Example 1 Serial Multiple-link System with Optical Fiber Cable
Host computer
RS-422 or RS-232C
Link Adapter
3G2A9-AL004-(P)E
Optical fiber (APF/PCF/H-PCF)
Optical fiber
(APF/PCF/H-PCF)
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit

4
As shown above, more than one Host Link Unit can be connected in series using
optical fiber. If, however, any failure (due to power failure, disconnection, etc.)
occurs in one of the Units, the series connection will cause all subsequent Host
Link Units to cease to operate. This can be prevented by using Link Adapters
such as the 3G2A9-AL002-PE Link Adapter shown in the following example.
These Link Adapters bypass any Host Link Unit not connected properly so that
the rest of the system can operate normally.
Example 2 Parallel Multiple-link System with Optical Fiber Cable
Host computer
RS-422C or RS-232C cable
Link Adapter
3G2A9-AL004-(P)E
C-series PC
with Optical
Host Link Unit
Link Adapter
3G2A9-AL002-PE
Link Adapter
3G2A9-AL002-PE
Link Adapter
3G2A9-AL002-PE
Link Adapter
3G2A9-AL002-PE
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit
C-series PC
with Optical
Host Link Unit
Even if a power failure occurs in a Host Link Unit connected to a branch line of a
Link Adapter, signals are still transmitted to the other Host Link Units.
Example 3 Single-link System with RS-232C Cable
In a system where a RS-232C cable connects a Host Link Unit directly to a host
computer, only one Host Link Unit can be connected to that host computer, i.e., it
has a single-link. The following Host Link Units can be used in this type of system:
3G2A5-LK201-EV1, C200H-LK201-V1, C500-LK203, and 3G2A6-LK201-EV1. It
should be noted that the PC onto which the Host Link Unit is mounted could have
another Host Link Unit connected directly or indirectly connected to another host
computer.
Host computer Host Link Unit

5
Example 4 Multiple-link System with RS-232C and RS-422 Cable
By using RS-422 cable, more than one Host Link Unit can be connected to the
same host computer to make a multiple-link system.
Host computer
RS-232C cable
Link Adapter
3G2A9-AL004-(P)E
C-series PC
with Host Link
Unit
RS-422 cable
RS-422 cable
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
Example 5 Multiple-link Multiple-level System
In this example, Rack-mounting and CPU-mounting Host Link Units are com-
bined to control a C500 PC from two host computers. A CPU-mounting Host Link
Unit is also combined with two Rack-mounting Host Link Units (C500-LK103(-P)
or C500-LK203, or both) on another PC, a C1000H or C2000H, to control this PC
from all three host computers. Furthermore, two C200H Rack-mounting Host
Link Units (C200H-LK101-PV1 or C200H-LK202-V1, or both) are combined to
control a C200H/HS/HX/HG/HE PC from a third host computer.

6
All lines connecting to host computers would have to be RS-232C cable. All oth-
er lines could be RS-422 cable or optical fiber cable, depending on the particular
Host Link Units and Link Adapters used. Note that the host computer on the up-
per right is considered to be in a single-link system with the Host Link Unit direct-
ly beneath it, despite the fact that other Host Link Units connect the same PC to
other host computers.
Host computer Host computer
Link Adapter
Link Adapter Link Adapter
C200H Expansion
I/O Rack with
Rack-mounting
Host Link Unit
C500 PC with
Rack-mounting and
CPU-mounting
Host Link Unit
Link Adapter Link Adapter
Host computer
C1000H or C2000H
PC with 2
Rack-mounting and
1 CPU-mounting
Host Link Units
RS-232C
C200H/HS/HX/HG/
HE PC with Rack-
mounting Host Link
Unit
1-3 Mounting Host Link Units
The I/O slots onto which the Host Link Units can be mounted are as follows:
PC I/O slot
C200H/C200HS/C200HX/C200HG/C200HE Any* slot of the CPU or Expansion I/O Racks
C500, C1000H with 3G2A5-BC081,
3G2A5-BC051, or C500-BC031
Backplane
Any of the three slots on the right hand side of the CPU Rack
with C500-BC082, C500-BC052,
C500-BC091, or C500-BC061
Backplane
Any of the five slots on the right hand side of the CPU Rack
C2000H simplex system with 3G2C5-BC061 Backplane Any of the slots on the CPU Rack
C2000H duplex system with 3G2C5-BI082 Backplane Any of the six slots on the Expansion I/O Rack
* If mounted to either of the rightmost slots of the CPU Rack, other peripheral devices, such as the Programming Console,
cannot be mounted.
Note Host Link Unit switches must be set before mounting.
Mounting Host Link Units Section 1-3

7
1-4 Host Computer Settings
To establish correct data communications with the Host Link Unit, the communi-
cations conditions listed below must match on both the host computer and the
Host Link Unit. For the actual setting of these conditions, refer to the host com-
puter manual.
Transmission Speed The transmission speed of the Host Link Unit must match that of the host com-
puter. See Section 2 Host Link Unit Characteristics for the setting procedure.
Set the host computer to the following 11-bit data format (7-bit ASCII):
Number of start bits: 1
Data Length: 7 bits
Even (vertical) parity: 1 bit
Number of stop bits: 2
For the C200H-LK101-PV1, C200H-LK202-V1, C500-LK103(-P), and
C500-LK203 Host Link Units, the following 11-bit format can also be set (8-bit
JIS). Make sure that the host computer and Host Link Unit formats match.
Number of start bits: 1
Data length: 8 bits
Parity (odd or even): 1 bit
Number of stop bits: 1
1-5 Types of Interfaces
The system must be properly interfaced to enable error-free communications.
Use the following information to correctly interface your system.
1-5-1 Optical Interface
In an optical fiber system, the maximum transmission distance varies depending
on the type of optical fiber cable, which in turn depends on the Host Link Unit
model. Refer to the table under in Appendix C for optical fiber cable lengths. Op-
tical fiber cable connectors must be assembled by the user.
The products listed in the following table can be used to interface the
C500-LK203, 3G2A5-LK201-EV1, C200H-LK201-V1, or the 3G2A6-LK201-EV1
Host Link Unit to a host computer.
Product Model Number Quantity Required Miscellaneous
Optical Interface Z3RN-A-5 2 RS-232C - optical converter interface
Optical Fiber Cable Z3F2-4DjM* 1 ---
AC Adapter Z3GP-01 1 or 2 For supplying power to optical interface
* When ordering, replace the “j” with the desired cable length: 1, 5, 10, 20, 30, 50, 100, 200, 400, or 500 m, e.g., Z3F2-4D30M
to order a 30 m cable.
Note 1. The optical interface must be provided with a 5 V power supply.
2. To supply 5 V to a Z3RN-A-5 Optical Interface connected on the host comput-
er side of a Host Link Unit (only with C500-LK203 or C200H-LK201-V1 mod-
els), set the 5 V supply switch on the back of the Host Link Unit to ON (up).
The normal setting is OFF.
3. When using a 3G2A5-LK201-EV1 or the 3G2A6-LK201-EV1 Host Link Unit,
use the AC adapters to supply 5 V to the Optical Interface on both the Host
Link Unit side and the host computer side.
Single-character Data
Format
Types of Interfaces Section 1-5

FG
SG
SD
RD
RS
CS
Shielded cable
FG
SG
SD
RD
RS
CS
Host Link Unit Host computer
DSR input not available
8
1-5-2 RS-232C Interface
(For all but C500-LK203 and insulated types.) When using an optical fiber cable
or RS-422 cable, several Host Link Units can be connected to one host comput-
er. When RS-232C cables are used, however, the connection must be made on
a one-to-one basis, or a Link Adapter must be used to convert to RS-422 cable or
optical fiber cable as shown inExamples 1 and 2 in 1-2-2 System Examples (see
also Link Adapters Installation Guide). The table below gives the proper connec-
tions for a RS-232C interface.
Signal* Symbol Pin No.
Frame ground FG 1
Signal ground SG 7
Send data SD 2
Receive data RD 3
Request to send RS 4
Clear to send CS 5
Equipment Ready ER 20
Send signal element timing 1*** ST1 24
Send signal element timing 2*** ST2 15
Receive timing*** RT 17
5-V power supply** 5V 14
* Viewed from the Host Link Unit.
** For Optical Interfaces used with the C500-LK203 Host Link Unit.
***For synchronous timing (not available with C200H-LK201-V1Host Link Unit).
The maximum cable length is 15 m. Ground the FG terminals of both the PC and
the host computer at a point that has a resistance of less than 100 Ω.

9
Interfacing to IBM AT via AL004 Link Adapter
FG
TX
RX
RTS
CTS
SG
DTR
1
2
3
4
5
7
20
CD
RX
TX
CTS
RTS
SG
DSR
DTR
RI
1
2
3
8
7
5
6
4
9
RS232-C
Host Link
Unit
IBM AT
computer
DB-9
Two-wire system, no handshaking.
FG
TX
RX
RTS
CTS
SG
DTR
1
2
3
4
5
7
20
1
2
3
8
7
5
6
4
9
RS232-C
Host Link
Unit
IBM AT
computer
DB-9
CD
RX
TX
CTS
RTS
SG
DSR
DTR
RI
Full handshake configuration.

10
Interfacing to IBM XT via AL004 Link Adapter
FG
TX
RX
RTS
CTS
SG
DTR
1
2
3
4
5
7
20
FG
RX
TX
CTS
RTS
SG
DSR
DTR
RI
1
3
2
5
4
7
6
20
22
RS232-C
Host Link
Unit
IBM XT
computer
DB-9
Two-wire system, no handshaking.
FG
TX
RX
RTS
CTS
SG
DTR
1
2
3
4
5
7
20
FG
RX
TX
CTS
RTS
SG
DSR
DTR
RI
1
3
2
5
4
7
6
20
22
RS232-C
Host Link
Unit
IBM XT
computer
DB-9

11
1-5-3 RS-422 Interface
(For all but C500-LK203 and insulated types) The following table details the pin
connections for a RS-422 interface.
Send data A SDA 9
Send data B SDB 5
Receive data A RDA 6
Receive data B RDB 1
Signal ground SG 3
Frame ground FG 7
RDB
RDA
SDB
SDA
SG
FG
RDB
RDA
SDB
SDA
SG
FG
Termination resistance *
Shielded wire
Host Link Unit Link Adapter 3G2A9-AL004(-P)
Termination resistance *
* The total termination resistance must be 100 Ω min.
The built-in resistance is 220 Ω.
1 6 5 9 3 7 1 6 5 9 3 7
FGSG SG FG
The maximum cable length is 500 m. Ground the FG terminals on both the PC
and the host computer to a point where the resistance is less than 100 Ω. For
more information, refer to the PC or host computer manuals.

12
Interfacing to IBM AT via AL004 Link Adapter
CD
TX
RX
RTS
CTS
SG
DSR
DTR
RI
1
3
2
7
8
5
6
4
9
1
2
3
4
5
7
6
20
8
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
IBM AT
DB-9
OMRON 3G2A9-AL004-(P)E
Link Adapter
RS-422
Host Link Unit
DB-9
Two-wire system, no hand-shaking.
FG
TX
RX
RTS
CTS
SG
DSR
DTR
CD
DB-25 DB-9
RI
XT
RX
RTS
CTS
SG
DSR
DTR
CD
9
3
2
7
8
5
6
4
1
FG
TX
RX
RTS
CTS
SG
DSR
DTR
CD
1
2
3
4
5
7
6
20
8
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
IBM AT
DB-9
Link Adapter
DB-25 DB-9
RS-422
Host Link Unit
DB-9

13
Interfacing to IBM XT via AL004 Link Adapter
FG
TX
RX
RTS
CTS
DSR
SG
CD
DTR
1
2
3
4
5
6
7
8
20
FG
TX
RX
RTS
CTS
DSR
SG
CD
DTR
1
2
3
4
5
6
7
8
20
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
IBM XT
DB-25
Link Adapter
RS-422
Host Link Unit
DB-9
Two-wire system, no hand-shaking.
DB-25 DB-9
FG
TX
RX
RTS
CTS
DSR
SG
CD
DTR
1
2
3
4
5
6
7
8
20
FG
TX
RX
RTS
CTS
DSR
SG
CD
DTR
1
2
3
4
5
6
7
8
20
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
RDB(+)
SG
SDB(+)
RDA(–)
SDA(–)
FG
1
2
3
4
5
6
9
8
7
IBM XT
DB-25
Link Adapter
RS-422
Host Link Unit
DB-9
DB-25 DB-9

14
RS-422 Interface (For Insulated C500-LK203)
The table below lists the connections for interfacing a RS-422 cable to an insu-
lated C500-LK203 Host Link Unit.
Send data A SDA 9
Send data B SDB 5
Receive data A RDA 6
Receive data B RDB 1
Frame ground FG 7
Frame ground** FG Hood fitting
** In order to prevent current flow in the shield
wire, make a connection to only one end of it.
Either pin 7 or the hood fitting can be used to
connect the shield wire to the frame ground.
RDB
RDA
SDB
SDA
FG
RDB
RDA
SDB
SDA
Termination resistance*
Shielded wire
Link Adapter 3G2A9-AL004(-P)Host Link Unit
Termination resistance*
1 6 5 9 7** 7
FG
* The total termination resistance must be 100 Ω min.
The built-in resistance is 220 Ω.
In order to prevent current flow in the shield
wire, make a connection to only one end of it.
Either pin 7 or the hood fitting can be used to
connect the shield wire to the frame ground.
**
FG
1 6 5 9
The maximum cable length is 500 m. Ground the FG terminals of both the PC
and the host computer to a point with a resistance of less than 100 Ω. For details,
refer to the PC or host computer manuals.
C500-LK203 Noise Tolerance The RS-422 interface on the C500-LK203 Host Link Unit is insulated to improve
its tolerance to electrical noise. Although the increased tolerance provides bet-
ter performance under normal operating conditions, the operation ca be affected
in very noisy environments. For this reason the optical C500-LK103(-P) is rec-
ommended in situations where noise might be a problem.

15
In systems which use only the insulated C500-LK203 Host Link Units, connect
the frame ground to the shield wire at the connections to the Host Link Units and
at either end of the connections between Link Adapters. In systems using the
insulated C500-LK203 with other types of Host Link Units, connect the frame
ground to the shield wire at connections to the C500-LK203 Host Link Units and
at both ends of all connections between Link Adapters and between the other
Host Link Units and Link Adapters.
Multiple-link Connections When connecting a multiple-link system with RS-422 cable, use shielded
twisted pair cables for the Host Link Unit. The total cable length of the entire sys-
tem must not exceed 500 m. The length of each branch line should be kept to
less than 10 m.
The optical Host Link Units can be used to achieve greater distances in the over-
all system (see Example 2 in 1-2 System Configuration). If they are connected in
series, however, signals are not transmitted to any Unit that is not supplied with
power, or any other Units beyond it. To avoid any problems with this, signals can
also be distributed through Link Adapter 3G2A9-AL002-PE. To connect the Host
Link Units to the host computer, Link Adapter 3G2A9-AL004-(P)E is necessary
to be able to interface the optical fiber cables and the RS-232C and RS-422
cables.
1-6 Wiring RS-232C and RS-422 Cable Connectors
The following procedures should be followed when wiring RS-232C and RS-422
connectors.
1-6-1 Preparation for Connecting Shielded Cable to FG
The procedures listed below correspond to the following diagrams.
1, 2, 3... 1. Cut the cable to the required length.
2. Use a razor blade to cut away the sheath (being careful not to damage the
braiding underneath): 25 mm for RS-422 cable; 40 mm for RS-232C cable.
3. Use scissors to cut away all but 10 mm of the exposed braiding.
4. Use wire strippers to remove the insulation from the last 5 mm of each wire.
5. Move the boot to cut the edge of the sheath and fold the braiding back over
the end of it.
6. Wrap aluminum foil tape over the top of the braiding on top of the boot for
one and a half turns.
Aluminum foil tape
FG Connections for
Insulated C500-LK203
Host Link Units
Wiring RS-232C and RS-422 Cable Connectors Section 1-6

16
1-6-2 Preparation for Connecting Unshielded Cable to FG
The procedures outlined in the list below correspond to the following diagrams.
1, 2, 3... 1. Cut the cable to the required length.
2. Use a razor blade to cut away the sheath: 25 mm for RS-422 cable; 40 mm
for RS-232C cable.
3. Use scissors to cut away the exposed braiding.
4. Use wire strippers to remove the insulation from the last 5 mm of all wires.
5. Wrap insulating tape over the top and end of the the cut sheath.
Electrician’s
tape
Soldering Observe the following when soldering the prepared wires onto the connectors.
1, 2, 3... 1. Place heat-shrinking tubes over all wires, far enough away from the end so
as not to interfere with the soldering.
2. Pre-solder all wires and connector terminals.
3. Solder wires, inserting 4 mm of the exposed 5 mm of wire into the connector
terminal.
Soldering iron
Heat-shrinking tube
(Internal diameter
1.5mm, ȏ=10)
1 mm
4. Move the heat-shrinking tubes onto the soldered area and shrink them into
place.
Heat-shrinking tube

17
Hood Assembly Assemble the hood as shown in the following diagram.
Ç
ÇAluminum foil tape
Hood (FG) connected
to shield wire
Hood (FG) not connected
to shield wire
Boot
1-6-3 FG Connection to the Cable’s Shield Wire (RS-422 Interface)
When connecting a Host Link Unit and a Link Adapter, connect the cable’s shield
wire to the Host Link Unit’s FG. Do not connect the shield wire to the Link Adapt-
er’s FG.
When connecting two Link Adapters, connect the cable’s shield wire to either
Link Adapter’s FG.
f
×
×
f
f
×
×
f
f f
Link Adapter
3G2A9-AL004-E
Link Adapter
3G2A9-AL004-E
C500-LK203 C500-LK203 C500-LK203
C2000H C500 C1000H
Link Adapter
3G2A9-AL004-(P)E
Host computer
RS-232C (15 m max.)
Note Just one end of the shield wire is connected to FG to prevent current from
flowing in the shield wire.
f: Connect the shield wire to FG.
×: Do not connect the shield wire to FG.
Connection of C500-LK203
Host Link Units

18
When connecting a C500-LK203 and a Link Adapter, connect the cable’s shield
wire to the C500-LK203 Host Link Unit’s FG. Do not connect the shield wire to
the Link Adapter’s FG.
When connecting a Host Link Unit (other than a C500-LK203) and a Link Adapt-
er, connect the both ends of the cable’s shield wire to the FGs. Also connect both
ends to the FG’s when connecting two Link Adapters.
f
f
f
f
×
f f
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
C500-LK203
C2000H C500 C1000H
Link Adapter
3G2A9-AL004-(P)E
f f
fRS-422
Host computer
RS-232C (15 m max.)
3G2A5-LK201-EV1 3G2A5-LK201-EV1
Note Just one end of the shield wire is connected to FG to prevent current from
flowing in the shield wire.
f: Connect the shield wire to FG.
×: Do not connect the shield wire to FG.
1-6-4 Wiring
Optical Host Link Units (C200H-LK101-PV1, 3G2A5-LK101-(P)EV1,
C500-LK103(-P), and 3G2A6-LK101-(P)EV1) are connected sequentially with
Optical Fiber Cable. Consequently, Units cannot transmit if they follow a Unit
that is turned off. Branches can be made in the Optical Fiber Cable with a
3G2A9-AL002-(P)E Link Adapter.
When connecting a host computer, a 3G2A9-AL004-(P)E Link Adapter is re-
quired to convert Optical Fiber Cable to RS-232C or RS-422.
Connection of C500-LK203
with other Host Link Units
Connection of Optical Host
Link Units

!
19
Wiring Example
2
3
4
5
6
7
8
20
RS-
232C
inter-
face
2
3
4
5
6
7
8
20
1
Host Computer
Shield
1
SD
RD
RS
CS
DR
SG
CD
ER
FG
5
6
1
3
7
9
SDB
RDA
RDB
SG
FG
SDA
0 V 0 V
RS-232C
RS-422
0 V
LG
FG
5 V
24 V
0 V
200 VAC
100 VAC
Optical Fiber Cable
C500 CPU Rack
Transmission
Reception
Optical Host Link Unit To next Host Link Unit 3G2A9-AL004-(P)E Link Adapter
Fuse
AC power
supply
Ground
(100 Ω or less)
Termination resistance
OR/
switching
circuit
External
CTS
switching
Be sure to use a wire of at least 1.25 mm2 in thickness.
Use M4 screws for tightening crimp terminals.
Use ring crimp terminals for wiring. Do not connect bare stranded wires directly
to terminal blocks.
Caution Tighten the screws on the terminal block of the AC Power Supply Unit to a torque
of 1.2 N⋅m. The loose screws may result in burning or malfunction.
Switch Settings
Set to “0 V” when the CTS (Clear-To-Send) signal will usually be ON. Set to “Ex-
ternal” when the signal is received externally. This switch is normally set to “0 V.”
Note Always cap unused Optical Connectors. If the connectors are not capped,
ambient light interference can enter the Optical Connectors and cause trans-
mission errors.
CTS (CS) Switching (Link
Adapter Settings)

20
The following diagram shows a 1:1 connection of a host computer and a Host
Link Unit (C200H-LK202-V1, 3G2A5-LK201-EV1, C500-LK203, or 3G2A6-
LK202-EV1).
Wiring Example
RS-
232C
inter-
face
1
2
3
4
5
6
7
8
20
1
2
3
4
5
6
7
8
20
FG
SD
RD
RS
CS
SG
ER
RS-
232C
inter-
face
Shield
Host computer
Host Link Unit
C200H-LK201-V1
3G2A5-LK201-EV1
C500-LK203
3G2A6-LK201-EV1
See note
Note It is not necessary to connect the RS and CS signals if the CTS switch on the
back of the Host Link Unit is set to 0 V.
Set the I/O port switch on the back of 3G2A5-LK201-EV1/C500-LK203 Host
Link Units to “RS-232C.”
Set to 0 V when the CTS (Clear-To-Send) signal will usually be ON. Set to Exter-
nal when the signal is received externally. This switch is normally set to 0 V.
Wiring Example
Transmission
LG
FG
1
2
3
4
5
6
7
8
20
1
2
3
4
5
6
7
8
20
FG
SD
RD
RS
CS
DR
SG
CD
ER
9
5
6
1
3
7
SDA
SDB
RDA
RDB
SG
FG
9 5 6 1 3 7
9
5
6
1
3
7
9
5
6
1
3
7
9
5
6
1
3
7
Shield
Shield Shield
0 V 0 V
0 V
5 V
24 V
100 VAC
200 VAC
0V
RS-
232C
inter-
face
RS-
422
inter-
face
RS-
422
inter-
face
RS-232C RS-422
Fuse
Host computer
To a 3G2A9-AL001 Link
Adapter or a Host Link Unit
Reception
OR
switching
circuit
Ex-
ternalCTS
Switch
ing
AC power
supply
Ground
(100 Ω or less)
Host Link Unit
C200H-LK202-V1
3G2A5-LK201-EV1
C500-LK203
3G2A6-LK202-EV1
Link Adapter
3G2A9-AL001
1:1 Connection of Host
Computer and Host Link
Unit
1:N Connection of Host
Computer and Host Link
Unit

!
21
Note Set the I/O port switch on the back of 3G2A5-LK201-EV1/C500-LK203 Host
Link Units to “RS-422.”
to terminal blocks.

23
SECTION 2
Host Link Unit Characteristics
This section provides the switch location and setting details for each group of Host Link Units. The Units are grouped accord-
ing the operating characteristics. C200H Units are dealt with first, followed by C500 and 3G2A5 models, and 3G2A6 models
are included at the end of the section.
For each grouping, labelled pictures of the different models show the positions and names of the switches and connections.
The functions of the switches are then explained. The effects of the Host Link Units and other peripheral devices on the operat-
ing mode of the PC System are discussed, followed by a section on the I/O Response Times.
The systems and PCs that apply to each Host Link Unit are given in the table at the beginning of Section 1.
2-1 C200H Host Link Units 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1-1 Nomenclature and External Appearance 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1-2 Switch Settings 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1-3 Indicators 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1-4 PC Operating Modes 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1-5 Restart Bits and Error Flags 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1-6 I/O Response Time 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2-2 Switch Settings 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2-3 Indicators 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2-6 I/O Response Time 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3-2 Switch Settings 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3-3 Indicators 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3-6 I/O Response Time 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4 Installing and Removing Host Link Units 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24
2-1 C200H Host Link Units
2-1-1 Nomenclature and External Appearance
The following figures give details of switch types, selectors, and connectors for
your Host Link Unit. It will be necessary to refer to these diagrams from time to
time as you read further in the manual, particularly when reading the section on
2-1-2 Switch Settings.
C200H-LK201-V1
RUN indicator
SW3
Baud rate
Unit number (00 to 31)
SW1 SW2
x10 x1
SW4 Command level, parity,
and transmission code
XMT (transmit) indicator
ERROR indicator
RCV (receive) indicator
1 and 2 not used.
3: Link type (see p 27)
4: 5-V power supply (see later)
CTS selector
RUN indicator
SW3
Baud rate
SW1 SW2
x10 x1
ERROR indicator
Optical fiber connectors
APF, PCF or H-PCF
C200H-LK101-PV1
Front Panels
RS-232C
cable connector
DIP switch
ON (Single-link
System)
OFF (Multiple-link
System)
Link type
(see p 27)
Rear Panels
LK101-PV1
LK201-V1
LK101-PV1
C200H Host Link Units Section 2-1

25
C200H-LK202-V1
RUN indicator
SW3
Baud rate
SW1 SW2
x10 x1
ERROR indicator
RCV (receive)
indicator
ON (Single-link
System)
OFF (Multiple-link
System)
Termination
resistance switch
(see p 27)
ON
OFF
Front Panel
Link type selector
(see p 27)
RS-422 connector
Rear Panel
LK202-V1
2-1-2 Switch Settings
The following information provides details on correct settings for the range of
Host Link Units covered by this manual. Pay particular attention to the RUN/
STOP and MONITOR/NORMAL switches on the C1000H-style cards.
SW1 and SW2
These switches are used to set the Unit number. The same unit number must not
be specified for more than one Unit.
SW3: Baud Rate
The baud rate of the Host Link Unit, as determined by the following switch set-
tings, must match that of the host computer.
SW3 Baud rate
0 300 bps
1 600 bps
2 1,200 bps
3 2,400 bps
4 4,800 bps
5 9,600 bps
6 19,200 bps
7
8 Do not set
9

26
SW4: Command Level, Parity and Transmission Code
SW4 Command Level* Parity Transmission Code
0 1 Even ASCII 7 bit, 2 stop bits
1 1,2
2 1,2,3**
3 Do not set
4 1 Odd
5 1,2
6 1,2,3
7 Do not set
8 1 Even JIS 8 bit, 1 stop bit
9 1,2
A 1,2,3
B Do not set
C 1 Odd
D 1,2
E 1,2,3
F Do not set
* See descriptions of Command Levels at the end of this sub-section.
** Use this setting when using LSS (Ladder Support Software)
Mode Selection
C200H Units are automatically set to HOST mode. See 2-1-4 PC Operating
Mode for further details.

27
Termination Resistance
When using a RS-422 cable (C200H-LK202-V1 Host Link Units) throughout a
system, the Host Link Unit at each end of the cable system (as detailed in the
following diagram) must have the termination resistances connected by turning
ON the switch on the back of the panel. When this switch is set to ON, a built-in
termination resistance of 220 Ω is connected. When set to OFF, the termination
resistance is disconnected.
Host computer
RS-232C cable
Link Adapter
3G2A9-AL004-(P)E
C-series PC
with Host Link
Unit
RS-422 cable
RS-422 cable
Link Adapter
3G2A9-AL004-(P)E
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
Turn the termination resistance ON for these two Host Link Units.
CTS Selector
For RS-232C models (C200H-LK201-V1), the selector is set to 0 V, the
clear-to-send (CTS) signal is continuously ON. When the selector is set to exter-
nal, the Unit will respond to externally generated CTS signals. This is normally
set to CTS always ON, i.e., the switch is set to ON.
5-V Power Supply Switch
When using a Z3RN-A-5 Optical Interface with an RS-232C Host Link Unit, the
5 V power supply switch should be set to ON; otherwise it should be set to OFF.
On the C200H-LK201-V1, pin 4 on the back-panel DIP switch functions as the
5 V power supply switch.
Link Type Selector
Pin 3 on the back-panel DIP switch of the C200H-LK201-V1 (RS-232C connec-
tion), and the Link Type Selector on the rear of the C200H-LK101-PV1 (optical
fiber connection) provide the same functions as described below.
OFF (Single-link):
If set to OFF, the Host Link Unit is connected to the host computer on a
one-to-one basis (see Example 3 and Example 5 under 1-2 System Configura-
tion. The Unit number and Frame Checksum (FCS) settings are not required.
The normal setting is ON (see below).

28
ON (Multiple-link):
If set to ON, up to 32 Host Link Units can be connected to one host computer. The
unit number and FCS must be specified, even if only one Host Link Unit is con-
nected to the host computer. When using Ladder Support Software, LSS, the
switch must be set to ON.
Command Levels
1, 2, 3... 1. Enables data areas to be read and, when the CPU has been correctly set
via the SC (Status Write) command, data can also be written.
2. Enables program transfers and reading or writing of I/O tables.
3. I/O READs can be performed and I/O tables can be registered. The Com-
mand Level should be set to “1, 2, 3” for running LSS software, program
transfers, etc. Other levels may be used for Systems Control Software,
monitoring, Data Acquisition Software, etc.
Note Commands valid for each level are listed in 3-1 Command Levels.
2-1-3 Indicators
Indicator Function
RUN ON when the Unit is operating. Depending on the settings of switches 1 to 4, this
indicator will blink when an error occurs. (See notes.)
RCV ON when the Host Link Unit is receiving data.
XMT ON when the Host Link Unit is transmitting data.
ERROR Goes ON when a transfer error is detected (See note 1.); goes OFF when a new
command is received normally.
Goes ON when an error is detected in communications with the CPU. The RUN
indicator will blink in this case. (See note 2.)
Note 1. Transfer errors include parity, framing, overrun, and FCS errors.
2. Operation of the Unit is stopped when the RUN indicator is OFF or blinking.
Restart the Unit after setting switches 1 to 4 correctly.
3. Refer to 5-4 Troubleshooting for details on correcting the following problems.
• The RUN indicator does not light.
• The Host Link Unit’s RCV indicator does not light when data is transmitted
from the host computer.
• The RCV indicator lights, but the XMT indicator does not.
• The ERROR indicator lights.
• The XMT indicator lights, but the host computer does not receive the data.
2-1-4 PC Operating Modes
The operating mode of the PC depends on the Memory Unit’s Initial Mode set-
ting, the RUN/STOP on the any CPU-mounted Host Link Unit, and the status of
any peripheral device connected to the PC. Refer to the following table for de-
tails.
PC Mode on Applying Power with the Host Link Unit Mounted
System configuration Memory Unit Initial Mode setting
and Host Link Unit setting Normal (OFF) Run (ON)
With no CPU-mounted device RUN RUN
With CPU-mounting Host Link Unit RUN RUN
STOP PROGRAM
With CPU-mounting peripheral device PROGRAM
With Programming Console The mode is determined by the mode selector on the Console,
i.e., RUN, MONITOR or PROGRAM.

29
Data Flow
The diagram below shows the flow of data between the system using C200H
Host Link Units, and a Programming Console. As can be seen, the Programming
Console can be used for monitoring, or for writing to the PC System.
Write data
PC operation mode,
program and I/O data,
set value and present
value data
FORCED SET/RESET
Monitoring the PC Controlling the PC
Read data
Program, I/O data,
error, etc.
Host computer
C-series PC with
Host Link Unit
Programming Console
Controlling PC Start-up
PROGRAM mode cannot be achieved manually when C200H Rack-mounting
Host Link Units are used without a Programming Console or other peripheral de-
vice. Programming can be implemented, however, to prevent the PC from
automatically starting when the power is applied. This allows greater control and
the Unit can be started later with a command from the host computer. The
following is an example of a programmed start-up for a C1000H PC.
Initialization
12800
12801
DIFU(13) 12801
JMP(04) **
12800
JMP(05) **
END(01)
Appropriate initialization codes must be programmed between JMP(04) and
JME(05). IR area bit 12800 can then be turned on to start PC operation from the
host computer. The PC must be set in MONITOR mode for this to be possible. To
initialize the PC when starting operation, use DIFU with the Always ON Flag; the
Reset Flag cannot be used. Refer to your PC’s operation manual for specific
bits. The PC’s operating mode can then be changed from the host computer af-
ter operation has begun. When programming in this fashion, note the following
conditions:
1, 2, 3... 1. Before turning on the IR area bit 12800, set the C200H Host Link Units to
MONITOR mode using the host computer.
2. JMP command numbers must be between 01 and 99 for C200H/HS,
C1000H, and C2000H PCs.

30
Sending a RUN Start Command to the PC
The following flowchart shows the computer decision making processes for en-
suring that the PC is in RUN mode after start-up.
Power application
Read PC operation
mode.
PC in RUN
mode?
END
STATUS WRITE
(RUN)
YES
NO
2-1-5 Restart Bits and Error Flags
Host Link Units use some of the Special Relay (SR) area and Auxiliary Relay
(AR) area bits of the PC to restart the communications control program of the
Host Link Unit and to indicate the occurrence of communications errors between
the Unit and the computer. The word (Wd) addresses and bit numbers of these
bits are as follows:
Bit 15 Bit 14 Bit 12Bit 13 Bit 11 Bit 10 Bit 1Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 2Bit 3 Bit 0
RM* #0
connection
error flag
CM*
restart
bit
CM*
error
flag
RM* #1
connec-
tion error
flag
RM* #1
HC**
error flag
RM* #0
HC**
error flag
RM* #0
CPU**
error flag
RM* #1
CPU**
error flag
* RM: Rack-mounting Host Link Unit
** HC: Error between the Host Link Unit and the host computer
CPU: Error between the Host Link Unit and the CPU of the PC
SRWd252SRWd253ARWd00ARWd24
RM* #1
connection
error flag
CM*
restart
bit
RM* #0
connection
error flag
CM: CPU-mounting Host Link Unit
RM* #1
Transmis-
sion ready
(C200HS/
HX/HG/HE
only)
RM* #0
Transmis-
sion ready
(C200HS/
HX/HG/HE
only)
ARWd267

!
31
Host Link Unit Restart Bit
When this bit is turned ON, the Host Link Unit is reset to its initial conditions, as if
the power had just been applied.
Caution Do not turn this bit ON in the user program; doing so could cause the memory to
be lost.
Host Link Unit Error Flag
This flag turns ON if a transmission error occurs between the PC and the Host
Link Unit. It turns ON the error indicator on the front of the Unit.
Note 1. When the Host Link Unit Restart bit is turned ON, the Host Link Unit Error
Flag is turned OFF.
2. Set the Host Link Unit to LOCAL mode before force setting or force resetting
an error flag.
3. With all but C200H Rack-mounting Host Link Units, communications be-
tween the Host Link Unit and the host computer will not be resumed until the
Restart bit is turned OFF. The initialization process is repeated as long as the
Restart bit is ON.
ON(=1)
OFF(=0)Restart bit
C200H Units restart.
4. If the error condition does not clear, disconnect and then reconnect the power
to the PC.
Error Location
The following example for a Rack-mounting Host Link Unit with an assigned op-
erating level 0, indicates the process flow used in locating errors.
Error in
communications data
between Host Link Unit
and host computer.
CPU doesn’t recognize
Host Link Unit.
Start
AR0013
OFF?
END
AR2414
ON?
25311
OFF?
ON
OFF
OFF
OFF
ON
ON
Host Link Unit not
mounted correctly.
Host Link Unit faulty;
replace it.
Error in refresh
operation between CPU
and Host Link Unit.
Restart Host Link Unit.
Check the command.
Host Link
Unit
connection
error
Error
between
Host Link
Unit and
PC’s CPU
Error
between
Host Link
Unit and
host
computer
•
•
•
•
•
•
•

32
2-1-6 I/O Response Time
The processing that determines and the methods for calculating the minimum
and maximum times required from an input on one PC with a Host Link Unit to an
output on another PC with a Host Link Unit are described below. The transfer
between the PCs is handled through a host computer connected to both these
PCs.
Processing and calculations are described by PC model in the first subsection
and for Systems combining C200H/HS/HX/HG/HE and C1000H PC models in
the last subsection. Although more precise equations may be written if required,
those used in the following calculations do not consider fractions of a cycle.
The calculations used in this section assume that all host computer commands
and PC responses require no more than one host link servicing period to com-
plete transmission. To compute response times for situations involving a longer
command and/or response, the number of host link servicing periods (i.e., the
number of cycles) required to complete the command or response would have to
be incorporated into the equations.
In considering response times, it is important to remember the sequence of pro-
cessing that occurs during the PC cycle. The main factor that affects the re-
sponse time is the timing of inputs and outputs and of host computer processing
in relation to this sequence.
The following diagram illustrates the setup used in response time calculations
Host computer
Host Link
Unit # 0
PC
Host Link
Unit # 31
PCcycle time
(50 ms)
cycle time
(30 ms)
x +Input
Output
The following equations can be used as required to calculate the minimum and
maximum response times with the C200H. The maximum response time is an
approximation.
Minimum response time = Input ON delay + Command transmission time + (cycle time of PC for Unit #0 x 3) + Response transmis-
sion time + Host computer processing time + Command transmission time + (cycle time of PC for Unit #31
x 3) + Output ON delay
Maximum response time = Input ON delay + Command transmission time + (cycle time of PC for Unit #0 x 10) + Response transmis-
sion time + Host computer processing time + Command transmission time + (cycle time of PC for Unit #31
x 10) + Output ON delay
Combined Systems
When transferring data from one model of PC through a host computer and then
out to a different model of PC, all that is necessary is to combine the first half of
the minimum/maximum equation for the origin PC with the second half of that for
the destination PC. For example, the following equation can be used for the mini-
mum response time when transferring from a C200H/HS/HX/HG/HE to a
C1000H.
Minimum response time = Input ON delay + Command transmission time + (cycle time of PC for Unit #0 x 3) + Response transmis-
sion time + Host computer processing time + Command transmission time + Output ON delay

33
2-2 C500 (3G2A5) Host Link Units
2-2-2 Switch Settings. These Units are suitable for use with C500, C1000H, and
C2000H PCs.
RUN indicator
ERROR indicator
(Parity, framing, overrun, and FCS errors)
Reset switch
* APF or PCF can be connected
to the LK103-PEV1.
Only PCF can be connected
to the LK103-EV1.
C500-LK103(-P)
3G2A5-LK101-(P)EV1
C500-LK103(-P)
3G2A5-LK101-(P)EV1
RUN indicator
ERROR indicator
(Parity, framing, overrun, and FCS errors)
Reset switch
to the LK101-PEV1.
Only PCF can be connected to
the LK101-EV1.
Mode selector
SW1
SW2
Front Panels Rear Panels
C500 (3G2A5) Host Link Units Section 2-2

34
3G2A5-LK201-EV1
RUN indicator
ERROR indicator
(Parity, framing, overrun,
and FCS errors)
Mode selector
RS-232C cable connector
See Example 3 in 1-2
System Configuration
for restrictions with RS-232C
cable.
RS-422 cable connector
I/O port selector
RS-422
RS-232C
Synchronization
selector
Internal
External
Termination
resistance switch
OFF
ON
CTS selector
0V (always ON)
External
SW1
SW2
RUN indicator
ERROR indicator
(Parity, framing, overrun,
and FCS errors)
for restrictions with RS-232C
cable.
Reset switch
C500-LK203
SW1
SW2
5-V power supply
ON
OFF
I/O port selector
RS-422
RS-232C
Synchronization
selector
Internal
External
Termination
resistance switch
OFF
ON
C500-LK203
CTS selector
0V (always ON)
External
Front Panels Rear Panels
3G2A5-LK201-EV1

35
Host Link Units covered by this manual. Pay particular attention to the RUN/
STOP and MONITOR/NORMAL switches on the C1000H-style cards.
SW1
SW1 will perform one of two different functions depending on the Unit. In both
instances, the first five pins are used to set the Unit number as shown below.
Details about SW1 and SW2 settings are included following the diagram.
1 2 3 4 5 Unit No.
OFF OFF OFF OFF OFF 0
OFF OFF OFF OFF ON 1
OFF OFF OFF ON OFF 2
OFF OFF OFF ON ON 3
OFF OFF ON OFF OFF 4
OFF OFF ON OFF ON 5
OFF OFF ON ON OFF 6
OFF OFF ON ON ON 7
OFF ON OFF OFF OFF 8
OFF ON OFF OFF ON 9
OFF ON OFF ON OFF 10
OFF ON OFF ON ON 11
OFF ON ON OFF OFF 12
OFF ON ON OFF ON 13
OFF ON ON ON OFF 14
OFF ON ON ON ON 15
ON OFF OFF OFF OFF 16
ON OFF OFF OFF ON 17
ON OFF OFF ON OFF 18
ON OFF OFF ON ON 19
ON OFF ON OFF OFF 20
ON OFF ON OFF ON 21
ON OFF ON ON OFF 22
ON OFF ON ON ON 23
ON ON OFF OFF OFF 24
ON ON OFF OFF ON 25
ON ON OFF ON OFF 26
ON ON OFF ON ON 27
ON ON ON OFF OFF 28
ON ON ON OFF ON 29
ON ON ON ON OFF 30
ON ON ON ON ON 31
ON MONITOR
OFF NORMAL
6 7 Parity Transmission code
OFF OFF Even ASCII 7-bit
OFF ON Odd 2 stop bits
ON OFF Even JIS 8-bit
ON ON Odd 1 stop bit
Parity/Transmission Code Selector
(C500 models)
MONITOR/NORMAL
selector
(C500 models)Unit No.
C500-LK103(-P)/-LK203 and
3G2A5-LK101-(P)EV1/-LK201-EV1 Host Link Units
ON RUN
OFF STOP
OR
RUN/STOP
selector
(3G2A5 models)
OFF ON OFF ON 300bps
ON OFF OFF ON 600bps
OFF OFF OFF ON 1,200bps
ON ON ON OFF 2,400bps
OFF ON ON OFF 4,800bps
ON OFF ON OFF 9,600bps
OFF OFF ON OFF 19,200bps
OFF: Multiple-link
ON: Single-link
7 8 Valid levels
OFF OFF ---
ON OFF 1
OFF ON 1 and 2
ON ON 1, 2, and 3
Command Levels
Operating Level
ON: Level 0
OFF: Level 1
C500-LK103(-P))/-LK203 and
3G2A5-LK101-(P)EV1/-LK201-EV1
Host Link Units
SW1
SW2
Note Each Unit must be given
a different unit number.
Baud rate
Link Type Selector

!
36
When pin 8 is set to RUN (ON), the CPU will start in RUN mode upon power
application. When set to STOP (OFF), the CPU will start operation in PRO-
GRAM mode. (Refer to to the 2-2-4 PC Operation Mode for further details.)
When pin 8 is set to MONITOR (ON), the PC will operate in MONITOR mode
upon the application of power. When the pin is set to NORMAL (OFF), the PC is
no longer controlled by the Host Link Unit (i.e., the mode of operation will be de-
termined by other system conditions). Refer to the 2-2-4 PC Operating Mode for
details.
SW2
Operating Level Set pin 5 of SW2 to OFF (operating level 1) when using a C500 PC and ON (op-
erating level 0) when using the Host Link Unit together with a SYSMAC NET Link
Unit. When using two Rack-mounting Host Link Units, set this pin to ON for one
of the Units, and to OFF for the other.
Caution Failure to set pin 5 correctly may damage components or prevent operation.
ON (Single-link)
If pin 6 is set to ON, the Host Link Unit is connected to the host computer on a
one-to-one basis (see Example 3 under 1-2 System Configuration). The Unit
number and Frame Checksum (FCS) settings are not required. The normal set-
ting is OFF (see below).
OFF (Multiple-link)
If pin 6 is set to OFF, up to 32 Host Link Units can be connected to one host com-
puter. The unit number and FCS must be specified, even if only one Host Link
Unit is connected to the host computer. When using Ladder Support Software,
LSS, pin 6 must be set to OFF.
1. Enables data areas to be read and, when the CPU has been correctly set via
the SC (Status Write) command, data can also be written.
2: Enables program transfers and reading or writing of I/O tables.
3: I/O reads can be performed and I/O tables can be registered. The Com-
mand Level should be set to 1, 2, and 3 for running LSS software, program trans-
fers, etc. Other levels may be used for Systems Control Software, monitoring,
Data Acquisition Software, etc.
Mode Selector
The Mode Selector (3G2A5-LK101/201) sets the Host Link Unit in to HOST or
LOCAL mode. In HOST mode, the host computer can set the operating mode of
the PC or write data to its memory. In LOCAL mode, the operating mode is speci-
fied by a programming device connected to the PC; such as a Programming
Console. This switch is locked by removing the key with the HOST mode se-
lected. See 2-2-4 PC Operating Mode for further details.
Reset Switch
By pressing the Reset Switch the Host Link Unit is forced to the initial status.
Synchronization Selector
Sets the Host Link Unit to either an internal or external clock. Normally, an inter-
nal clock is employed. But, when a synchronization modem with a baud rate of
2,400 bps or higher is used, the external clock setting must be selected.
RUN/STOP Selector
(3G2A5-LK101/-LK201)
MONITOR/NORMAL
Selector (C500-LK103(-P),
C500-LK203)
Link Type Selector
Command Levels

37
When this switch is set to ON, a built-in termination resistance of 220 Ω is con-
nected. When set to OFF, the termination resistance is disconnected. When us-
ing a RS-422 cable throughout a system, the Host Link Unit at each end of the
cable system must have the termination resistances connected by turning ON
the switch as detailed in the following diagram. RS-232C systems provide point-
to-point connections and do not require a termination resistance.
Host computer
RS-232C cable
Link Adapter
3G2A9-AL004-(P)E
C-series PC
with Host Link
Unit
RS-422 cable
RS-422 cable
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
CTS Selector
When the selector is set to 0 V, the clear-to-send (CTS) signal is continuously
ON. When the selector is set to external, the Unit will respond to externally gen-
erated CTS signals. This is normally set to CTS always ON, i.e., the switch is set
to ON.
5-V Power Supply Switch
When using a Z3RN-A-5 Optical Interface, the 5 V power supply switch should
be set to ON; otherwise it should be set to OFF.
I/O Port Selector
Sets the Host Link Unit (3G2A5-LK201-EV1 or C500-LK203) to either the
RS-232C or the RS-422 interface.

38
2-2-3 Indicators
Indicator Function
RUN ON when the Unit is operating.
The operating mode of the PC depends an the setting of the mode selector on
the Host Link Unit, the RUN/STOP or MONITOR/NORMAL selector on the Host
Link Unit, and the status of any peripheral device connected to the PC. Refer to
the following tables for details.
Host Link Units in C500, C1000H, or C2000H Systems
(Except C500-LK103(-P) and C500-LK203 Host Link Units)
For Rack-mounting Host Link Units set to Host mode, the PC mode on initial
application of power is as set on the Host Link Unit, i.e., RUN if the setting is
RUN, and PROGRAM if the setting is STOP. (RUN/STOP setting is selected via
pin 8 of DIP switch 1 for all models.) If the Host Link Unit is set to LOCAL, start-up
mode will be as shown below.
System configuration and Host Link Unit setting* Rack-mounting Host Link Unit in LOCAL mode
No CPU-mounting device RUN
With CPU-mounting Host Link Unit RUN RUN
STOP PROGRAM
With CPU-mounting peripheral device PROGRAM
With Programming Console** The mode is determined by the mode selector on the Console,
i.e., RUN, MONITOR or PROGRAM.
* If there is no Rack-mounting Host Link Unit mounted, the data for the Rack-mounting Host Link Unit LOCAL mode applies.
** With the Host Link Unit mode set to HOST, a MODE SET ERR alarm occurs if the Programming Console is set to MONTR or PROG
and RUN is selected on the DIP switch, or if the Programming Console is set to RUN or MONTR with STOP selected.
The operating mode can be set from a host computer as long as the Host Link
Unit is set to HOST mode. If the Host Link Unit is set to LOCAL mode, the operat-
ing mode cannot be set from the host computer and must be set from the host
computer and must be set from a Peripheral Device, such as the Programming
Console.
C500-LK103(-P) and C500-LK203 Host Link Units
System configuration Host Link Unit mode
and Host Link Unit setting MONITOR NORMAL
No other mounted device MONITOR RUN
Programming Console The mode is determined by the mode selector on the Console., i.e.,
RUN, MONITOR, or PROGRAM.
CPU-mounting Host Link Unit RUN * RUN
STOP MONITOR PROGRAM
Host Link Unit MONITOR MONITOR** MONITOR**
NORMAL MONITOR** RUN**
CPU-mounted peripheral device MONITOR PROGRAM

39
* A CPU-mounting Host Link Unit must be set to STOP mode when used together with a Rack-mounting Host Link Unit
that is set to MONITOR mode.
** If a Programming Console is also mounted, the mode selector on the Programming Console determines the PC
operating mode.
If a peripheral device other than a CPU-mounting Host Link Unit is attached to
the CPU, the PC’s operating mode is determined by the peripheral device when
the Host Link Unit’s mode selector is set for LOCAL. With the mode selector set
for HOST, the PC’s operating mode is determined by the RUN/STOP selector on
the Host Link Unit.
Unless programming is implemented to prevent starting, if the PC is in RUN
mode, it will begin operation immediately the power is applied. Refer to
Controlling PC Start-up at the end of this subsection for details on programming
methods. These methods do not apply when using a 3G2A5-LK101-(P)EV1 or
3G2A5-LK201-EV1 Host Link Unit.
PC Mode When Mounting a CPU-mounting Host Link Unit with the Power ON
System configuration Rack-mounting Host Link Unit*
LOCAL HOST
V1 PCs** Operating mode unchanged Operating mode unchanged
Other PCs Mounting for the first time RUN RUN
STOP PROGRAM
Remounting (the Host Link Unit has been
mounted before)
Operating mode unchanged
* If there is no Rack-mounting Host Link Unit mounted, data for the Rack-mounting Host Link Unit LOCAL mode applies.
** V1 PCs are the C200H/HS/HX/HG/HE, C1000H, C2000H, and any other building-block PC with the suffix “V1” in the
model number.
Data Flow
HOST Mode The following figures show the flow of data between the system and a Program-
ming Console with the Host Link Unit set in HOST mode. As can be seen, the
Programming Console can be used for monitoring or writing in this mode.
Write data
PC operation mode,
program and I/O data,
set value and present
value data
FORCED SET/RESET
Monitoring the PC Controlling the PC
Read data
Program, I/O data,
error, etc.
Host computer
C-series PC with
Host Link Unit
Programming Console

40
LOCAL Mode The following diagram shows the flow of data while the Host Link Unit is in LO-
CAL mode. Note that in this mode the Programming Console can be used for
monitoring only.
Read data
Program, I/O data,
erros, etc.
Host computer
C-series PC with
Host Link Unit
Monitoring the PC
No write operations from host computer.
Programming Console
C500-LK103(-P) and C500-LK203 Host Link Unit Modes
These Units do not have mode selectors, i.e., PC operating modes can be set,
data can be written, and similar operations can be performed without regard to
HOST/LOCAL mode settings. Data flow is the same as that for HOST mode,
shown above.
Controlling PC Start-up
PROGRAM mode cannot be achieved manually when these Rack-mounting
Host Link Units are used without a Programming Console or other peripheral de-
vice. Programming can be implemented, however, to prevent the PC from
automatically starting when the power is applied. This allows greater control and
the Unit can be started later with a command from the host computer. The
following is an example of a programmed start-up of a C1000H PC.
Initialization
12800
12801
DIFU(13) 12801
JMP(04) **
12800
JMP(05) **
END(01)

41
Appropriate initialization codes must be programmed between JMP(04) and
JME(05). IR area bit 12800 can then be turned on to start PC operation from the
host computer. The PC must be set in MONITOR mode for this to be possible. To
initialize the PC when starting operation, use DIFU with the Always ON Flag; the
Reset Flag cannot be used. Refer to your PC’s operation manual for specific
bits. The PC’s operating mode can then be changed from the host computer af-
ter operation has begun. When programming in this fashion, note the following
conditions:
1, 2, 3... 1. Pin 8 of SW1 on C500-LK103(-P) or C500-LK203 Units should be set to
MONITOR. If it is not, use the host computer to change it to the MONITOR
mode before turning on IR area bit 12800.
2. JMP command numbers must be between 01 and 99 for C200H/HS,
C1000H and C2000H PCs.
3. This programming example cannot be applied to C500 PCs, which do not
support direct jumps. In this case, use a 3G2A5-LK101-(P)EV1 or
3G2A5-LK201-EV1 Host Link Unit so that the mode can be set manually.
The following flowcharts show the computer decision making processes for en-
3G2A5-LK101-(P)EV1 and 3G2A5-LK201-EV1 Host Link Units
Power application
Read PC operation
mode.
PC in RUN
mode?
Host
Link Unit in
HOST mode?
Set mode to HOST
STATUS WRITE
(RUN)
END
YES
YES
NO
NO

42
Power application
Read PC operation
mode.
PC in RUN
mode?
END
STATUS WRITE
(RUN)
YES
NO
C500
RM*
re-
start
bit
RM*
error
flag
CM*
restart
bit
CM*
error
flag
SRWd60SRWd61
C1000H and C2000H
RM* #0
error
flag
CM*
restart
bit
CM*
error
flag
RM* #1
error
flag
RM*
re-
start
bit
SRWd252SRWd253

!
43
C120
CM*
restart
bit
CM*
error
flag
* CM: CPU-mounting Host Link Unit
SRWd60
be lost.
Link Unit. It turns ON the error indicator on the front of the Unit.
Flag is turned OFF.
an error flag.
3. Communications between the Host Link Unit and the host computer will not
be resumed until the Restart bit is turned OFF. The initialization process is
repeated as long as the Restart bit is ON.
ON(=1)
OFF(=0)Restart flag
Host Link Unit stops and stands by.
Host Link Unit restarts.
4. If a reset switch is provided, pressing it should reset the Host Link Unit and
clear the error state.
5. If the Unit still won’t reset, disconnect and then reconnect the power to the
PC.
PCs.
Processing and calculations are described by PC model in the first subsection.
An example combining a C200H/HS/HX/HG/HE PC with a C1000H PC is in-
cluded in the C200H section. Although more precise equations may be written if
required, those used in the following calculations do not consider fractions of a
cycle.

44
Host computer
Host Link
Unit # 0
PC
Host Link
Unit # 31
PCCycle time
(50 ms)
Cycle time
(30 ms)
x +Input
Output
C120 and C500
Although the C120 and C500 equations for the minimum and maximum re-
sponse times are the same as those for the C1000H and C2000H, the break-
down of the CPU’s cycle differs. These groups are thus treated in different sec-
tions.
Minimum Response Time The data flow that will produce the minimum response time is shown below. This
flow assumes that all signals and data transmissions are processed as soon as
they occur. The equation for the minimum response time is given below the dia-
gram.
Cycle time
Input
signal
Output
signal
Cycle time
I/O refresh
I/O refresh
I/O response time
CPU reads
input signal
CPU writes
output signal
Output ON delayInput ON delay
Host link service
Buffer for Host
Link Unit # 0
Cycle time Cycle time
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Command/response for Unit # 0 Command/response for Unit # 31
Host link service
Overseeing
Minimum response time = Input ON delay + Command transmission time + Cycle time of PC for Unit #0 + Response transmission
time + Host computer processing time + Command transmission time + Output ON delay

45
Maximum Response Time The data flow that will produce the maximum response time is shown below. De-
lays over the minimum response time occur because the input to be transferred
through the host computer is received immediately following the I/O refresh peri-
od (requiring a wait to the next cycle) and because the command from the host
computer to write the bit to be output from PC for Unit #31 is received immediate-
ly following host link servicing (again requiring a wait to the next cycle). The
equation for the maximum response time is given below the diagram.
Cycle time
Input
signal
Output
signal
Cycle time
I/O refresh
I/O refresh
I/O response time
CPU reads
input signal CPU writes
output signal
Input ON delay
Host link service
Buffer for Host
Link Unit # 0
Cycle time
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Host link service
Cycle time
Output ON delay
Maximum response time = Input ON delay + Command transmission time + (Cycle time of PC for Unit #0 x 2) + Response
transmission time + Host computer processing time + Command transmission time + Cycle time of PC for
Unit #31 + Output ON delay

46
C1000H and C2000H
Although the C1000H and C2000H equations for the minimum and maximum
response times are the same as those for the 3G2A6 and C500, the breakdown
of the CPU’s cycle differs. These groups are thus treated in different sections.
gram.
Cycle time
Input
signal
Output
signal
Cycle time
Output refresh
Output refresh
I/O response time
CPU reads
input signal
CPU writes
output signal
Host link service
Buffer for Host
Link Unit # 0
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Input refresh
Input refresh
Host link service

47
ly following host link servicing (again requiring a wait to the next cycle). The
Cycle time
Input
signal
Output
signal
Cycle time
Output refresh
Output refresh
I/O response time
CPU reads
output signal
Input ON delay
Host link service
Buffer for Host
Link Unit # 0
Cycle time
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Host link service
Input refresh
Input refresh
Cycle time
Output ON delay

48
2-3 C120 (3G2A6) Host Link Units
2-3-2 Switch Settings. These Units can be used with all of the C-series
Rack-mounting PCs. (C120 Host Link Units are sometimes referred to as
3G2A6 Host Link Units.)
READY indicator
ERROR indicator
(Parity, framing,
overrun, and
FCS errors)
to the LK101-PEV1.
Only PCF can be connected to
the LK101-EV1.
for restrictions with
RS-232C cable.
3G2A6-LK101-(P)EV1 3G2A6-LK201-EV1 3G2A6-LK-202-EV1
SW2
SW1
Front Panels
Rear Panels
SW1 SW1
SW2 SW2
SW3SW3
3G2A6-LK101-(P)EV1 3G2A6-LK201-EV1 3G2A6-LK-202-EV1

49
3G2A6 Host Link Units covered by this manual.
SW1
For SW1, the first five pins are used to set the Unit number as shown below. De-
tails about SW2 settings are given following the diagram.
1 2 3 4 5 Unit No.
OFF OFF OFF OFF OFF 0
OFF OFF OFF OFF ON 1
OFF OFF OFF ON OFF 2
OFF OFF OFF ON ON 3
OFF OFF ON OFF OFF 4
OFF OFF ON OFF ON 5
OFF OFF ON ON OFF 6
OFF OFF ON ON ON 7
OFF ON OFF OFF OFF 8
OFF ON OFF OFF ON 9
OFF ON OFF ON OFF 10
OFF ON OFF ON ON 11
OFF ON ON OFF OFF 12
OFF ON ON OFF ON 13
OFF ON ON ON OFF 14
OFF ON ON ON ON 15
ON OFF OFF OFF OFF 16
ON OFF OFF OFF ON 17
ON OFF OFF ON OFF 18
ON OFF OFF ON ON 19
ON OFF ON OFF OFF 20
ON OFF ON OFF ON 21
ON OFF ON ON OFF 22
ON OFF ON ON ON 23
ON ON OFF OFF OFF 24
ON ON OFF OFF ON 25
ON ON OFF ON OFF 26
ON ON OFF ON ON 27
ON ON ON OFF OFF 28
ON ON ON OFF ON 29
ON ON ON ON OFF 30
ON ON ON ON ON 31
ON RUN
OFF STOP
RUN/
STOP
selectorUnit No.
SW1
OFF ON OFF ON 300bps
ON OFF OFF ON 600bps
OFF OFF OFF ON 1,200bps
ON ON ON OFF 2,400bps
OFF ON ON OFF 4,800bps
ON OFF ON OFF 9,600bps
OFF OFF ON OFF 19,200bps
OFF: Multiple-link
ON: Single-link
7 8 Valid levels
OFF OFF ---
ON OFF 1
OFF ON 1 and 2
ON ON 1, 2, and 3
Command levels
SW2
Note Each Unit must be given
a different unit number.
Link Type Selector
Baud rate
RUN/STOP Selector Refer to 2-3-4 PC Operating Modes for details.

!
50
SW2
Operating Levels Set pin 5 of SW2 to OFF (operating level 1) when using a C500(F) PC and ON
(operating level 0) when using the Host Link Unit together with a SYSMAC NET
Link Unit. When using two Rack-mounting Host Link Units, set this pin to ON for
one of the Units, and to OFF for the other.
Caution Failure to set pin 5 correctly may damage components or prevent operation.
MONITOR/NORMAL Selector When this switch is set to MONITOR, the PC will operate in MONITOR mode
upon the application of power. When the pin is set to NORMAL, the PC is no
longer controlled by the Host Link Unit (i.e., the mode of operation will be deter-
mined by other system conditions). Refer to 2-3-4 PC Operating Mode for de-
tails.
ON (Single-link) If pin 6 is set to ON, the Host Link Unit is connected to
the host computer on a one-to-one basis (see Example 3 and Example 5 under
1-2 System Configuration. The Unit number and Frame Checksum (FCS) set-
tings are not required. The normal setting is OFF (see below).
OFF (Multiple-link) If pin 6 is set to OFF, up to 32 Host Link Units can be
connected to one host computer. The unit number and FCS must be specified,
even if only one Host Link Unit is connected to the host computer. When using
Ladder Support Software, LSS, pin 6 must be set to OFF.
Pins 7 and 8 on SW2 control the operating command levels according to the fol-
lowing:
1: Enables data areas to be read and, when the CPU has been correctly set via
the SC (Status Write) command, data can also be written.
2: Enables program transfers and reading or writing of I/O tables.
3: I/O reads can be performed and I/O tables can be registered. The Com-
mand Level should be set to 1, 2, and 3 for running LSS software, program trans-
fers, etc. Other levels may be used for Systems Control Software, monitoring,
Data Acquisition Software, etc.
SW3
ON
OFF
OFF
ON
OFF
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
OFF
Unused
Internal synchronization
External synchronization
CTS always ON
External CTS signal
Unused
Termination resistance ON
Termination resistance OFF
3G2A6-LK201-EV1 3G2A6-LK202-EV1
Sets the Host Link Unit to either an internal or external clock. Normally, an inter-
nal clock is employed. But, when a synchronization modem with a baud rate of
2,400 bps or higher is used, the external clock setting must be selected.
Link Type Selector
Command Level
Synchronization Selector

51
When this switch is set to ON, a built-in termination resistance of 220 Ω is con-
nected. When set to OFF, the termination resistance is disconnected. When us-
ing a RS-422 cable throughout a system, the Host Link Unit at each end of the
cable system must have the termination resistances connected by turning ON
the switch as detailed in the following diagram. RS-232C systems provide point-
to-point connections and do not require a termination resistance.
Host computer
RS-232C cable
Link Adapter
3G2A9-AL004-(P)E
C-series PC
with Host Link
Unit
RS-422 cable
RS-422 cable
Link Adapter
3G2A9-AL004-(P)E
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
Link Adapter
3G2A9-AL001
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
C-series PC
with Host Link
Unit
When the selector is set to 0 V, the clear-to-send (CTS) signal is continuously
ON. When the selector is set to external, the Unit will respond to externally gen-
erated CTS signals. This is normally set to CTS always ON, i.e., the switch is set
to ON.
2-3-3 Indicators
Indicator Function
Ready ON when the power is on and the Unit is ready to transmit.
CTS Selector

52
The operating mode of the PC depends an the setting of the mode selector on
the Host Link Unit, the RUN/STOP or MONITOR/NORMAL selector on the Host
Link Unit, and the status of any peripheral device connected to the PC. Refer to
the following tables for details.
C500-LK103(-P), C500-LK203, and 3G2A6 Host Link Units
System configuration Host Link Unit mode
and Host Link Unit setting MONITOR NORMAL
No other mounted device MONITOR RUN
Programming Console The mode is determined by the mode selector on the Console., i.e.,
RUN, MONITOR, or PROGRAM.
CPU-mounting Host Link Unit RUN * RUN
STOP MONITOR PROGRAM
Host Link Unit MONITOR MONITOR** MONITOR**
NORMAL MONITOR** RUN**
CPU-mounted peripheral device MONITOR PROGRAM
* A CPU-mounting Host Link Unit must be set to STOP mode when used together with a Rack-mounting Host Link Unit
that is set in MONITOR mode.
** If a Programming Console is also mounted, the mode selector on the Programming Console determines the PC
operating mode.
If a peripheral device other than a CPU-mounting Host Link Unit is attached to
the CPU, the PC’s operating mode is determined by the peripheral device when
the Host Link Unit’s mode selector is set for LOCAL. With the mode selector set
for HOST, the PC’s operating mode is determined by the RUN/STOP selector on
the Host Link Unit.
Unless programming is implemented to prevent starting, if the PC is in RUN
mode, it will begin operation immediately the power is applied. Refer to
Controlling PC Start-up at the end of this subsection for details on programming
methods.
PC Mode When Mounting a CPU-mounting Host Link Unit with the Power ON
System configuration Rack-mounting Host Link Unit*
LOCAL HOST
V1 PCs** Operating mode unchanged Operating mode unchanged
Other PCs Mounting for the first time RUN RUN
STOP PROGRAM
Remounting (the Host Link Unit has been
mounted before)
Operating mode unchanged
* If there is no Rack-mounting Host Link Unit mounted, data for the Rack-mounting Host Link Unit LOCAL mode applies.
** V1 PCs are the C200H/HS/HX/HG/HE, C1000H, C2000H, and any other building-block PC with the suffix “V1” in the
model number.

53
Caution Sticker The CPU-mounting 3G2A6-LK101-(P)EV1 Host Link Unit is supplied with a cau-
tion sticker. The caution sticker should be attached as shown below if the RUN/
STOP selector is set to RUN. This is to avoid the potential danger of the Host
Link Unit being mounted to an unprepared system.
Attach here
The following flowchart shows the computer decision making processes for en-
Power application
Read PC operation
mode.
PC in RUN
mode?
Host
Link Unit in
HOST mode?
Set mode to HOST
STATUS WRITE
(RUN)
END
YES
YES
NO
NO

!
54
C120 (3G2A6)
CM*
restart
bit
CM*
error
flag
* CM: CPU-mounting Host Link Unit
SRWd60
be lost.
Link Unit. The error indicator on the front panel of the Unit lights while this flag is
ON.
Flag is turned OFF.
an error flag.
3. Communications between the Host Link Unit and the host computer will not
be resumed until the Restart bit is turned OFF. The initialization process is
repeated as long as the Restart bit is ON.
ON(=1)
OFF(=0)Restart bit
Host Link Unit stops and stands by.
Host Link Unit restarts.
4. To reset error condition on the Host Link Unit, disconnect and then reconnect
the power to the PC.

55
PCs.
Processing and calculations are described by PC model. Although more precise
equations may be written if required, those used in the following calculations do
not consider fractions of a cycle.
Host computer
Host Link
Unit # 0
PC
Host Link
Unit # 31
PCCycle time
(50 ms)
Cycle time
(30 ms)
x +Input
Output

56
C120 and C500
Although the C120 and C500 equations for the minimum and maximum re-
sponse times are the same as those for the C1000H and C2000H, the break-
down of the CPU’s cycle differs. These groups are thus treated in different sec-
tions.
gram.
Cycle time
Input
signal
Output
signal
Cycle time
I/O refresh
I/O refresh
I/O response time
CPU reads
input signal
CPU writes
output signal
Host link service
Buffer for Host
Link Unit # 0
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Host link service
Overseeing

57
ly following host link servicing (again requiring a wait until the next cycle). The
Cycle time
Input
signal
Output
signal
Cycle time
I/O refresh
I/O refresh
I/O response time
CPU reads
output signal
Input ON delay
Host link service
Buffer for Host
Link Unit # 0
Cycle time
Buffer for Host
Link Unit # 31
PC for Host
Link Unit # 31
PC for Host
Link Unit # 0
Host computer
Host computer
processing time
Command Command
Response Response
Host link service
Cycle time
Output ON delay
2-4 Installing and Removing Host Link Units
This section explains the proper installation and removal of CPU-mounting Host
Link Units.
Note Never install or remove Rack-mounting Host Link Units when the power supply
is on.
Follow the procedure below when installing a CPU-mounting Host Link Unit on a
PC.
1, 2, 3... 1. Remove the Connecting Cables.
2. Recheck the settings of the DIP switches on the back of the Unit.
In particular, check the RUN/STOP switch. If the switch is set to RUN, the
PC might begin operating when the Host Link Unit is inserted. The PC’s
mode will not change if the switch is set to STOP.
Refer to 2-1-4 PC Operating Modes for details on the Host Link Unit’s effect
on the PC’s mode.
Installation of a
CPU-mounting Host Link
Unit
Installing and Removing Host Link Units Section 2-4

58
3. Connect the Host Link Unit to the PC’s Peripheral Device port and tighten
the mounting screws.
4. Connect the Connecting Cable and tighten the mounting screws.
Follow the procedure below when removing a CPU-mounting Host Link Unit
from a PC.
1, 2, 3... 1. Remove the Connecting Cable.
2. Remove the Host Link Unit.
When a CPU-mounting Host Link Unit is installed or removed during transmis-
sion, a transmission error will occur after removal if the host computer initiated
communications with the affected Unit. The following table describes the ap-
propriate procedure to follow.
Event Host Link Unit Indicator
Status
Host Computer Status Corrective Action
Host Link Unit installed. ERROR indicator lit. Transmission error occurs. Retransmit from the host
computer.
Host Link Unit was
removed.
--- Transmission error occurs. Ignore the affected Host
Link Unit’s transmission
Host Link Unit has been
removed.
--- Transmission error occurs.
error or reconfigure so that
transmission to that Unit will
not be attempted.
It is recommended to prepare a program that processes transmission errors in
order to prevent an error with one Unit from stopping the entire system. Refer to
Section 5 Error Processing for details.
Removal of CPU-mounting
Host Link Units
Transmission Errors
Installing and Removing Host Link Units Section 2-4

59
SECTION 3
Programming
This section gives the information required for effective programming of the Host Link Units. It lists the commands and re-
sponses for Host Link Units. The basic formats for that they can take are described and the data representation explained. 3-1
Command Levels lists all of the commands and responses which apply to Host Link Units and the operation level at which they
operate. Also refer to 3-2 Communications Protocol for basic format information (see also Section 4 Commands and Re-
sponses for the command and response formats of each instruction).
3-1 Command Levels 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2 Communications Protocol 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2-1 Block Format 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2-2 Block Format With More Than One Frame 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2-3 Data Representation 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2-4 System Checks 66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2-5 Data Transaction Test Program 66. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3 Communications Protocol (C200HS/HX/HG/HE only) 67. . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3-1 Command Timing 68. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-4 Frame Checksum (FCS) Calculation 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-4-1 FCS Calculation Program Example 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

60
3-1 Command Levels
The following tables give the commands and responses available for the Host
Link Units, the command levels, and the modes in which they are applicable. De-
tails of the command and response formats are given in Section 4 Commands
and Responses.
Level 1
Header Name PC Mode Applicable
Code RUN MNTR PROG PCs
TS TEST Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
MS STATUS READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
MF ERROR READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
RR IR/SR AREA READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
RH HR AREA READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
RJ AR AREA READ Valid Valid Valid H-type: C200H/HS/
HX/HG/HE, C1000H,
C2000H
RL LR AREA READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
RG TC STATUS READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
RD DM AREA READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
RX FM INDEX READ Valid Valid Valid C1000H, C2000H
RF FM DATA READ Valid Valid Valid C1000H, C2000H
RC TC PV READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
R# SV READ 1 Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
R$ SV READ 2 Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
R% SV READ 3 Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
SC STATUS WRITE Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WR IR/SR AREA WRITE Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WH HR AREA WRITE Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WJ AR AREA WRITE Not valid Valid Valid H-type: C200H(S),
C1000H, C2000H
Command Levels Section 3-1

61
Header ApplicablePC ModeName
Code PCsPROGMNTRRUN
WL LR AREA WRITE Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WG TC STATUS WRITE Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WD DM AREA WRITE Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WF FM AREA WRITE Not Valid Valid Valid C1000H, C2000H
WC TC PV WRITE Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
W# SV CHANGE 1 Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
W$ SV CHANGE 2 Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
W% SV CHANGE 3 Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
KS FORCED SET Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
KR FORCED RESET Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
FK MULTIPLE FORCED SET/RESET Not Valid Valid Valid C200H/HS
FR MULTIPLE FORCED SET/RESET STATUS READ Not Valid Valid Valid C200H/HS
KC FORCED SET/RESET CANCEL Not Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
MM PC MODEL READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
CR DM AREA HIGH-SPEED READ Valid Valid Valid C1000H, C2000H
XZ ABORT and INITIAL (command only) Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
IC Undefined command (response only) Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
EX TRANSMIT Valid Valid Not valid C200HS
Varies Unprocessed command (response only) Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
Level 2
RP PROGRAM READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
WP PROGRAM WRITE Not valid Not valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
Command Levels Section 3-1

62
Header ApplicablePC ModeName
Code PCsPROGMNTRRUN
RI I/O TABLE READ Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
MI I/O TABLE GENERATE Not valid Not valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
Level 3
QQ COMPOUND COMMAND Valid Valid Valid All: C120, C200H/HS/
HX/HG/HE, C500,
C1000H, C2000H
3-2 Communications Protocol
The host computer has initial transmission priority. Data transfer between the
host computer and the Host Link System is, therefore, initiated when the com-
puter sends a command to a PC in the Host Link System.
A set of data in a transmission is called a block. The data block sent from the host
computer to the Host Link System is called a command block. The block sent
from the Host Link System to the computer is called a response block. In a multi-
ple-link communications system, each block starts with a unit number and a
header, and ends with a Frame Checksum (FCS) code and a terminator (: and
CR). In a single-link system, however, each block starts with only a header, and
ends with only a terminator. The terminator in the command block enables the
PC to send a response. The terminator in the response block enables the host
computer to send another command. Examples of communications are in-
cluded at the end of Section 4 Commands and Responses.
3-2-1 Block Format
X101 X100
Unit no. 00 to 31 Header Text FCS Terminator
FCS calculation range
@ X X X X X X CR
*
A block is usually made up of one unit called a frame, but long blocks of data
(over 131 characters) must be divided into more than one frame before trans-
mission. In a multiple-link system, the first frame can have up to 131 characters,
and subsequent frames can have up to 128 characters. In a single-link system,
however, every frame (the first included) has up to 128 characters. The data
must then be divided into more than one frame when there is a block consisting
of more than 131 characters in a multiple-link system, and of more than 128
characters in a single-link system. In this case, the beginning and intermediate
blocks end with a delimiter (CR), instead of a terminator (:CR).
Communications Protocol Section 3-2

63
3-2-2 Block Format With More Than One Frame
Multiple-link System
First Frame (131 Characters or Less)
X101 X100
Unit no. 00 to 31 Header Text no. 1 (123 characters max.) FCS
@ X X X X X X CR
Delimiter
Intermediate Frame(s) (128 Characters or Less)
Text no. 2 to M–1 (125 characters max.) FCS
X X CR
Delimiter
Last Frame (128 Characters or Less)
Text no. M (124 characters max.) Terminator
X X CR
*
FCS
Single-link System
First Frame (128 Characters or Less)
Header Text no. 1 (125 characters max.)
X X CR
Delimiter
Intermediate Frame(s) (128 Characters or Less)
Text no. 2 to M–1 (127 characters max.)
CR
Delimiter
Last Frame (128 Characters or Less)
Text no. M (126 characters max.) Terminator
CR
*

64
Sending Commands To send a command block with more than one frame from the computer, initially
send only the first frame in the block. Do not send the next frame until the host
computer has received the delimiter which should have been sent back from the
PC. Do not separate data from a single word into different frames for any write
command.
UnitNo.
Header
Text
FCS
Delimiter
Text
FCS
Delimiter
Text
FCS
UnitNo.
Header
Text
FCS
Delimiter
Delimiter
HostcomputerHostLinkUnit
Next frame transmis-
sion
enabled
Next frame transmis-
sion
enabled
Response
block
Terminator
Terminator
First frame Intermediate frame End frame
Command block
Receiving Commands To receive a response block consisting of more than one frame from the PC, the
host computer must send the carriage return code (delimiter) to the PC after re-
ceiving the delimiter from the PC. This enables the PC to send the next frame.
UnitNo.
Header
Text
FCS
Text
FCS
Delimiter
Delimiter
HostcomputerHostLinkUnit
Next frame
transmission enabled
Intermediate
frame End frame
Command block
Terminator
UnitNo.
Header
Text
FCS
Delimiter
First frame
Text
FCS
Terminator
Delimiter
Response
block
Next frame
transmission enabled
3-2-3 Data Representation
The format examples in this manual apply to multiple-link systems. The explana-
tion for each command/response includes the ranges of the possible data (e.g.,
program instructions to be read, operand values, etc.). The actual data that is
valid for the system depends on the PCs being used. Therefore, it is important
that you check that the program instructions and the data areas (and sizes) are
available for the PCs in your system.

65
Numerical data within a transmission is expressed in hexadecimal, decimal, or
binary format. Refer to the format example of each command for details. The
appropriate range is indicated in the following manner. Conversion tables in Ap-
pendix C give data conversions from ASCII to hex, binary, and decimal, and
those in Appendix D give conversions between hex, BCD, binary, and decimal
up to the value 32dec.
Note All ASCII data is stored as hex in the PCs.
Hexadecimal Data
X163 X162 X161 X160
In the above diagram, the elements X163 to X160 indicate that the data is ex-
pressed in hexadecimal. Each digit can, therefore, be in the range from 0 (ASCII
48dec, binary 0000) to 9 (ASCII 49dec, binary 1001), or A (ASCII 65dec, binary
1010) to F (ASCII 70dec, binary 1111).
Decimal Data
X103 X102 X101 X100
In this figure, X103 to X100 indicate that the data is expressed in decimal. Each
digit can, therefore, be in the range from 0 (binary 0000) to 9 (binary 1001).
Binary Data
X23 X22 X21 X20
ON/
OFF
ON/
OFF
ON/
OFF
ON/
OFF
In the above figure, the ON/OFF and X23 to X20 indicate that the data is binary.
Each box therefore represents either 0 or 1 as follows:
0 (ASCII 48dec): OFF
1 (ASCII 49dec): ON.
Data Areas Data area codes must be entered in capital letters and must be 4 characters
wide. Names shorter than 4 characters must be followed by spaces (ASCII
32dec) to make up the 4 characters. Data areas valid for each command are
listed with the command.
A maximum of 29 words of PC data can be sent at the same time. If a command
is used to read or write more than 29 words, the transmission will be divided into
units of 29 words or less each.
Although the C200H/HS/HX/HG/HE, C1000H, and C2000H will complete pro-
cessing a read or write command in one cycle, other PCs may require up to three
cycles to complete processing for all the data being transferred.
If separate commands are used to read data from a PC, the data may not all
result from the same PC program cycle.

66
3-2-4 System Checks
Prior to an actual data transaction between the Host Link Unit and host comput-
er, check the system by following the nine steps listed below.
1, 2, 3... 1. Check the settings of the Host Link Unit’s DIP switches and selectors. make
sure the transmission speeds, specified interfaces, and data formats of
both the Host Link Unit and host computer match.
2. Mount the Host Link Unit to the PC.
3. Connect the Host Link Unit to the host computer with the proper cable. For
details, refer to Sections 1 Introduction and 2 Host Link Unit Characteris-
tics.
4. Apply power to the PC and the host computer.
5. If the ERROR or ALARM indicators on the PC illuminate, rectify the error
and then clear the alarm.
6. If the Host Link Unit is ready, the RUN indicator will illuminate. Confirm that
this is ready before proceeding.
7. Prepare and execute a test program on the host computer.
8. If the data test is completed successfully, the system is operational.
9. If an error occurs, perform the required error processing as detailed in Sec-
tion 5 Error Processing.
3-2-5 Data Transaction Test Program
The following program example is designed to send test data to the Host Link
Unit and return it, unaltered, to the host computer. By executing this program, the
transmit and receive data are both displayed on the screen of the host computer.
If the transmit data and the receive data match, the system is operational. The
example uses a multiple-link system, and the program is executed by Host Link
Unit number 0. The following program is for NEC computers. For IBM compa-
tibles, four lines must be changed as shown after the program.
NEC
10 CLOSE #1
20 CLS
30 ON ERROR GOTO *EROPE
40 OPEN ”COM:E73” FOR OUTPUT AS #1 Opens RS-232C. ....................
50 ’*********************************************
60 *KEYIN
70 INPUT ”TEST DATA INPUT –––––”,TDS Test data input. .................
80 ICS=”@OUTS” Creation of Unit no. and header code. ............................................
90 TS=TCS+TDS Creation of test command. .............................................
100 GOSUB *FCSSET Calculation of Frame Checksum. ........................................
110 TXDS=TS+FCSS+”*” Send data set. .....................................
120 PRINT TXDS Send data display. ............................................
130 PRINT #1,TXDS Transmission. ........................................
140 INPUT #1,RXDS Reception. ........................................
150 LINE PRINT RXDS Receive data display. ......................................
160 GOTO *KEYIN
170 ’*********************************************
180 *FCSSET *. ...............................................
190 L=LEN(TS) Number of transmit data before FCS. .............................................
200 A=0 Setting of initial value for EOR calculation. ....................................................
210 FOR J=I TO L
220 TJS=MIDS(TS,J,1)
230 A=ASC(TJS) XOR A
240 NEXT J
250 FCSS=HEXS(A)

67
260 IF LEN(FCSS)=1 THEN FCSS=”0”+FCSS
270 RETURN
280 ’*********************************************
290 *EROPE
300 PRINT ”ERL=”;ERL,”ERR=”;ERR Display of line no. containing error and error no.. .......................
310 CLOSE #1
320 END Closes RS-232C. ....................................................
330 ’*********************************************
* The FCS calculation subroutine starting from statement 180 is for data transmission. The data length L will differ for the response
because the response contains other data such as FCS and *.
To adjust the above program for IBM compatibles replace the following four
lines.
30 ON ERROR GOTO 300
40 OPEN “COM:E72” FOR OUTPUT AS#1
100 GOSUB 190
160 GOTO 70
3-3 Communications Protocol (C200HS/HX/HG/HE only)
Commands from the PC The C200HS/HX/HG/HE allows the PC to issue commands to the host computer
under the following conditions. The command makes it possible to send the PC’s
data to the host computer without using any command from the host computer.
1, 2, 3... 1. The C200HS/HX/HG/HE must be connected to the host computer via a
C200H-LK101-PV1, C200H-LK2jj-V1 Host Link Unit or the peripheral
port of the C200HS/HX/HG/HE’s CPU. Refer to the C200HS Operation
Manual or C200HX/HG/HE Operation Manual for details.
2. The TRANSMIT (TXD (––)) must be executed from the user ladder-dia-
gram program. Refer to 4-36 TRANSMIT for details.
When the TXD (––) instruction is executed, data is transmitted to the host com-
puter in the following format.
Command Format
X101 X100
FCS CR
*Data@ E XUnit no.
Designated data in
ASCII code.
The data (61 bits maximum) specified by the TXD (––) instruction is converted
into ASCII (122 characters maximum) and transmitted. There will be no re-
sponse from the host computer for the above command.
IBM
Communications Protocol (C200HS/HX/HG/HE only) Section 3-3

68
3-3-1 Command Timing
When the Host Link Unit is receiving a command from the host computer at the
time the execution of the TRANSMIT instruction has been completed, command
transmission to the host computer is possible only after the Host Link Unit com-
pletes receiving the command from the host computer. After receiving the com-
mand from the host computer, the Host Link Unit starts command transmission
to the host computer. The transmission of a response for the command from the
host computer is possible only after the command transmission to the host com-
puter is completed.
PC Data Transmission
Host Link Unit
Host computer
Command
Command
1
0
Response
Transmission Ready Flag 0: 26705
1: 26713
TXD instruction
received
TXD instruction
completed
When the Host Link Unit is transmitting a response for a command transmitted
from the host computer at the time the execution of the TRANSMIT instruction
has been completed, command transmission to the host computer is possible
only after the Host Link Unit completes transmitting the response to the host
computer. After transmitting the response, the Host Link Unit starts command
transmission to the host computer.
PC Data Reception
Host Link Unit
Host computer
Command
Response
1
0
Command
Transmission Ready Flag 0: 26705
1: 26713
TXD instruction
received
TXD instruction
completed
The transmission flag is ON when a command to the host computer is delivered
from the PC to the Host Link Unit.
Communications Protocol (C200HS/HX/HG/HE only) Section 3-3

69
3-4 Frame Checksum (FCS) Calculation
The Frame Checksum is 8-bit data converted into two ASCII characters. The
8-bit data is the result of an EXCLUSIVE OR sequentially performed between
each character, from the first character in the frame to the last character of the
text in that frame.
@ 1 0 R H 0 0 3 1 0 0 0 1 5 8 * CR
Unit no. TextHeader FCS Terminator
@ 0100 0000
XOR
1 0011 0001
XOR
0 0011 0000
XOR
R 0101 0010
0 0011 0000
XOR
1 0011 0001
0101 1000
0011 0101 0011 1000
FCS
Conversion
to ASCII
:
5 8
Calculation result
3-4-1 FCS Calculation Program Example
The following program is an example of how Frame Checksum calculations can
be performed on received data. For an example of a program to calculate the
FCS for Transmit Data, refer to 3-2-4 System Checks.
Transmit/receive data
Number of characters in FCS calculation range.
Receive data contains an FCS, delimiter,
terminator, etc. The ABORT command,
however, does not contain an FCS.
FCS calculation result
Receive FCS data
A space follows the semicolon if the
FCS reception is performed normally. If
it is not performed, ERR is displayed.
Note: in this example, CR (CHR$(13))
is not included in RESPONSE$.
FCS Calculation Section 3-4

71
SECTION 4
Commands and Responses
This section provides the command and response formats for all of the instructions covered by this manual. A table of the
responses produced for different errors is included in 4-45 Response Code List. Examples of communications between a Host
Link Unit and PC, for several commands, are given at the end of the 4-46 Communications Examples. The levels at which the
commands are applicable are given in table form in 3-1 Command Levels.
4-1 TEST 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2 STATUS READ 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3 ERROR READ 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4 IR AREA READ 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-5 HR AREA READ 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-6 AR AREA READ 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-7 LR AREA READ 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-8 TC STATUS READ 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-9 DM AREA READ 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-10 FM INDEX READ 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-11 FM DATA READ 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-12 PV READ 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-13 SV READ 1 78. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-14 SV READ 2 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-15 SV READ 3 80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-16 STATUS WRITE 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-17 IR AREA WRITE 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-18 HR AREA WRITE 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-19 AR AREA WRITE 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-20 LR AREA WRITE 82. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-21 TC STATUS WRITE 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-22 DM AREA WRITE 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-23 FM AREA WRITE 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-24 PV WRITE 84. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-25 SV CHANGE 1 85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-26 SV CHANGE 2 86. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-27 SV CHANGE 3 87. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-28 FORCED SET 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-29 FORCED RESET 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-30 MULTIPLE FORCED SET/RESET 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-31 MULTIPLE FORCED SET/RESET STATUS READ 90. . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-32 FORCED SET/RESET CANCEL 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-33 PC MODEL READ 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-34 DM HIGH-SPEED READ 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-35 ABORT and INITIALIZE 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-36 TRANSMIT (C200HS/HX/HG/HE only) 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-37 Response to an Undefined Command 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-38 Response Indicating an Unprocessed Command 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-39 PROGRAM READ 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-40 I/O TABLE READ 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-41 PROGRAM WRITE 94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-42 I/O TABLE GENERATE 94. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-43 I/O REGISTER 95. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-44 I/O READ 96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-45 Response Code List 97. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-46 Communications Examples 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

72
4-1 TEST
Transmits one block of data to the PC and then returns it, unaltered, to the host
computer. Each frame is treated as a block regardless of whether it uses a termi-
nator or delimiter.
Command Format
@ T S
X101 X100
Unit no. FCS CR
*Any characters (122 max.) other than a carriage return
Response Format
@ T S
X101 X100
Unit no. FCS CR
*Any characters (122 max.) other than a carriage return
Response if Error Occurs
@ T S
X101 X100
Unit no. CR
*
Response
code
X161 X160
4-2 STATUS READ
Reads the operating status of the PC.
Command Format
@ M S
X101 X100
Unit no. FCS CR
*
Response Format
@ M S
14 13 12 11 10 9 815
None: 0 0 0
8 kbytes: 0 0 1
16 kbytes: 0 1 0
24 kbytes: 0 1 1
32 kbytes: 1 0 0
48 kbytes: 1 0 1
64 kbytes: 1 1 0
6 5 4 3 2 1 07
Fixed to 16 characters
Not used
Program area
size
Program
area
RAM: 1
ROM: 0
Duplex System
Active: 1
Standby: 0
0 0: PROGRAM mode
0 1: None
1 0: RUN mode
1 1: MONITOR mode
1: Generation of
FALS instruction
1: Duplex
0: Simplex
1: Start switch is OFF
1: Error diagnosis in progress
1: FORCED SET/RESET in progress
1: Remote I/O waiting for power application
X101 X100
Response
code
0 1 15
Status data Message FCS CR
*X161 X160
Unit no.
X163 X162 X161 X160
*1
*2
*1
*1. Only possible for the C2000H
*2. Not possible for the C200H/HS/HX/HG/HE
STATUS READ Section 4-2

73
4-3 ERROR READ
Reads and clears errors in the PC. Also checks whether previous errors have
already been cleared. When both Rack- and CPU-mounting Host Link Units are
used in combination, errors in either type of Unit are indicated in the same man-
ner.
Command Format
@ M F
X101 X100
Unit no. FCS CR
*Error clear
00: Error is not
cleared
01: Error is cleared
X101 X100
Response Format
@ M F
X101 X100
1: FALS (CPU stops)
1: END instruction missing (F0)
1: Program error (F3)
1: Host Link Unit transmission error
1: RTI instruction error (F4)
1: PC link error
1: I/O bus error (C0 to 4)
1: JMP instruction error (F2)
1: Memory error (F1)
X161 X160
Response
code Error (first word)
FCS CR
*
14 13 12 11 10 9 815
1: FAL error
1: Duplex bus error
(C2000H only)
Intelligent I/O unit error
(C200H/HS only)
1: Battery failure (F7) 0 0 0: CPU Rack
0 0 1: Expansion I/O Rack 1
(Data from I/O bus)
0 0: Group 1 (control signal error)
0 1: Group 2 (data bus failure)
1 0: Group 3 (address bus failure)
1: Remote I/O error
(B0 to 3)
14 13 12 11 10 9 815
6 5 4 3 2 1 07
6 5 4 3 2 1 07
FAL, FALS No
X163 X162 X161 X160
Error (second word)
X163 X162 X161 X160
1: I/O verify error (F7)
1: cycle time over (F8)
1: I/O Unit over (E1)
1: I/O setting error (E0)
Unit no.
X161 X160
9900 ~
$99$00 ~
(C1000H, C2000H
only)
ERROR READ Section 4-3

74
4-4 IR AREA READ
Reads the contents of the specified number of IR area words, starting from the
specified word.
Command Format
@ R R
X101 X100
Unit no. FCS CR
*
Beginning word
X103 X102 X101 X100 X103 X102 X101 X100
No. of words
Response Format
@ R R
X101 X100
Unit no.
FCS CR
*
X161 X160 X163 X162 X161 X160 X163 X162 X161 X160
Response
code
Data from beginning
word
Data from second
word
4-5 HR AREA READ
Reads the contents of the specified number of HR area words, starting from the
specified word.
Command Format
@ R H
X101 X100
Unit no. FCS CR
*
Beginning word
X103 X102 X101 X100 X103 X102 X101 X100
No. of words
Response Format
@ R H
X101 X100
Unit no.
FCS CR
*
Data from beginning
word
X163 X162 X161 X160
Data from second
word
X163 X162 X161 X160
Response
code
X161 X160
4-6 AR AREA READ
Reads the contents of the specified number of AR area words, starting from the
specified word.
Command Format
@ R J
X101 X100
Unit no. FCS CR
*
Beginning word
X103 X102 X101 X100 X103 X102 X101 X100
No. of words
AR AREA READ Section 4-6

75
Response Format
@ R J
X101 X100
Unit no.
FCS CR
*
Data from
beginning word
X163 X162 X161 X160
Data from second
word
X163 X162 X161 X160
Response
code
X161 X160
4-7 LR AREA READ
Reads the contents of the specified number of LR area words, starting from the
specified word.
Command Format
@ R L
X101 X100
Unit no. FCS CR
*
Beginning word
X103 X102 X101 X100 X103 X102 X101 X100
No. of words
Response Format
@ R L
X101 X100
Unit no.
FCS CR
*
Data from
beginning word
X163 X162 X161 X160
Data from second
word
X163 X162 X161 X160
Response
code
X161 X160
4-8 TC STATUS READ
Reads the status of the Completion Flags of the specified number of timers/
counters, starting from the specified timer/counter.
Command Format
@ R G
X101 X100
FCS CR
*
Beginning
timer/counter
X103 X102 X101 X100 X103 X102 X101 X100
No. of
timers/counters
Unit no.
Response Format
@ R G
X101 X100
Unit no. ON/
OFF
ON/
OFF
FCS CR
*
Data from second timer/counter
Data from beginning timer/counter
X161 X160
Response
code
TC STATUS READ Section 4-8

76
4-9 DM AREA READ
Reads the contents of the specified number of DM words, starting from the spe-
cified word.
Command Format
@ R D
X101 X100
Unit no. Beginning word
X103 X102 X101 X100 X103 X102 X101 X100
No. of words
FCS CR
*
Response Format
@ R D
X101 X100
Unit no.
FCS CR
*
Response
code
X161 X160
Data from beginning
word
Data from second
word
X163 X162 X161 X160 X163 X162 X161 X160
4-10 FM INDEX READ
Reads the contents of the specified number of FM index blocks, starting from the
specified block.
Command Format
@ R X
X101 X100
Unit no. FCS CR
*
Beginning block
X103 X102 X101 X100 X103 X102 X101 X100
No. of blocks
Response Format
@ R X
X101 X100
Unit no.
FCS CR
*
Number of unused
blocks
X103 X102 X101 X100
Total number of
blocks
X103 X102 X101 X100
Response
code
X161 X160
0: All RAM
1: First half: RAM
Last half: EEPROM
If applicable
7 6 5 4 3 2 1 0
1: Write
protected
0: Not write
protected
1: END block
of PC program
X161 X160
Repeated for each block
0 0 0 No data stored. . .
0 0 1 I/O data. . .
0 1 0 PC program. . .
0 1 1 Comments. . .
1 0 0
1 0 1
1 1 0
1 1 1
Undefined. .
Memory
type
X160
X161 X160
Comments
No. per block
Data
type
X161 X160
FM INDEX READ Section 4-10

77
4-11 FM DATA READ
Reads the contents of the specified number of FM blocks, starting from the spe-
cified block. The “data type” and “comments per block” information can be add-
ed to each block, separated by a delineator, i.e., a comma (,).
Command Format
@ R F
X101 X100
Unit no. FCS CR
*
Beginning block
X103 X102 X101 X100 X103 X102 X101 X100
No. of unused
blocks
Response Format
0 0 0 No data stored. . .
0 0 1 I/O data. . .
0 1 0 PC program. . .
0 1 1 Comments. . .
1 0 0
1 0 1
1 1 0
1 1 1
No. of blocks: 0000, 1000, 2000
Read data
X161 X160 ,
Delineator
(end of
data block)
X163 X162
Read data
X161 X160 X163 X162
Read data
X161 X160
X163 X162
@ R F
X101 X100
Unit no.
FCS CR
*
Number of blocks
X103 X102 X101 X100
Response
code
X161 X160
Memory
type
0: All RAM
1: First half: RAM
Last half: EEPROM
X161 X160
Data type
X161 X160
Comments
per block
If applicable
7 6 5 4 3 2 1 0
1: Wrote
protected
0: Not write
protected
1: END block
of PC program
X161 X160
Undefined. .
X160
X163 X162
Read data
X161 X160 ,
Delineator
(end of
data block)
X161 X160
Data type
X161 X160
Comments
per block
4-12 PV READ
Reads the specified number of timer/counter PVs (present values), starting from
the specified timer/counter.
Command Format
@ R C
X101 X100
Unit no. FCS CR
*
Beginning
timer/counter
X103 X102 X101 X100 X103 X102 X101 X100
No. of
timers/counters
PV READ Section 4-12

78
Response Format
@ R C
X101 X100
Unit no.
FCS CR
*
Data from beginning
timer/counter
X103 X102 X101 X100
Data from second
timer/counter
X103 X102 X101 X100
Response
code
X161 X160
4-13 SV READ 1
Reads the set value (a constant) of the specified timer/counter instruction.
Reads from the beginning of the program and can therefore take up to 20 sec-
onds to produce a response. Refer also to 4-14 SV READ 2 and 4-15 SV READ
3.
Command Format
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
@ R #
X101 X100
TIM/CNT FCS CR
*
Word address
OR3 OR4OR1 OR2OP3 OP4OP1 OP2
Unit no.
0 0 0 0
to
0 1 2 7
0 0 0 0
to
0 5 1 1
Note 1. Dashes represent spaces.
2. The data in the brackets apply to the C200H, C200HS, C200HX, C200HG,
C200HE, C1000H, and C2000H.
Response Format
@ R #
X101 X100 X101 X100X103 X102
FCS CR
*X161 X160
Unit no.
Response
code Set value
If the command is used more than once, the set value of only the first instruction
will be read.
SV READ 1 Section 4-13

79
4-14 SV READ 2
Reads the set value (a constant, or data area and word) of the specified timer/
counter instruction. The timer/counter instruction is designated by its program
address. If the program has more than 9,999 addresses, use SV READ 3, de-
scribed in the next section.
Command Format
@ R $
FCS CR
X101 X100X101 X100
Address
X103 X102
*
TIM/CNT
OP3 OP4OP1 OP2
Unit no. Word address
0 0 0 0
to
0 1 2 7
0 0 0 0
to
0 5 1 1
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
X101 X100X103 X102
C200HE, C1000H, and C2000H.
Response Format
@ R $
X101 X100 X101
X103 X102 X101
Data area
FCS CR
*
C I O – IR area. . .
L R – – LR area. . .
H R – – HR area. . .
A R – – AR area. . .
D M – – DM area. . .
D M : – :DM area. . .
C O N – Constant. . .
Note: Dashes represent spaces.
X161 X160
Set valueUnit no.
Response
code
OP3 OP4OP1 OP2

80
4-15 SV READ 3
Reads the set value (a constant, or data area and word) of the specified timer/
counter instruction. The operation is similar to SV READ 2, but the SV READ 3 is
capable of reading from higher program addresses (up to 6 digits).
Command Format
@ R %
X101 X100 X105 X104 X103 X102
FCS CR
*
Address
X103 X102 X101 X100
X101 X100
TIM/CNT
OP1 OP2 OP3 OP4
Unit no.
Always 0
Word address
0 0 0 0
to
0 1 2 7
0 0 0 0
to
0 5 1 1
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
C200HE, C1000H, and C2000H.
Response Format
@ R %
X101 X100
FCS CR
*
Data area
X101
X103 X102 X101
Set value
X161 X160
Unit no.
Response
code
D M : – :DM area. . .
OP1 OP2 OP3 OP4

81
4-16 STATUS WRITE
Changes the operating mode of the PC according to the information entered into
word X160.
Command Format
@ S C Mode data
X161 X160
FCS CR
*
7 6 5 4 3 2 1 0
X161 X162
0 0 0 0 0 0
0 0: PROGRAM mode
1 0: MONITOR mode
1 1: RUN mode
X101 X100
Unit no.
Response Format
@ S C FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-17 IR AREA WRITE
Writes data to the IR area, starting from the specified word. Writing is done word
by word.
Command Format
@ W R
X101 X100
Unit no.
X103 X102 X101 X100 X161 X160
FCS CR
*
Beginning word
X163 X162 X161 X160X163 X162
Data for beginning
word
Data for second
word
Response Format
@ W R
X101 X100
FCS CR
*X161 X160
Unit no.
Response
code
IR AREA WRITE Section 4-17

82
4-18 HR AREA WRITE
Writes data to the HR area, starting from the specified word. Writing is done word
by word.
Command Format
X101 X100 X103 X102 X101 X100
FCS CR
*
Beginning word Data for beginning
word
Data for second
word@ W HUnit no.
X163 X162 X161 X160 X163 X162 X161 X160
Response Format
@ W H FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-19 AR AREA WRITE
Writes data to the AR area, starting from the specified word. Writing is done word
by word.
Command Format
X101 X100 X103 X102 X101 X100
FCS CR
*
word
Data for second
word@ W JUnit no.
X163 X162 X161 X160 X163 X162 X161 X160
Response Format
@ W J FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-20 LR AREA WRITE
Writes data to the LR area, starting from the specified word. Writing is done word
by word.
Command Format
X101 X100 X103 X102 X101 X100
FCS CR
*
word
Data for second
word@ W LUnit no.
X163 X162 X161 X160 X163 X162 X161 X160
LR AREA WRITE Section 4-20

83
Response Format
@ W L FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-21 TC STATUS WRITE
Writes the status of the Completion Flags to the TC area, starting form the speci-
fied timer/counter.
Command Format
@ W G FCS CR
X101 X100 X103 X102 X101 X100 *
Status of second timer/counter
Status of beginning timer/counter
Beginning timer/counter
0: OFF
1: ON
ON/
OFF
ON/
OFF
Timer/CounterUnit no.
Response Format
@ W G FCS CR
X101 X100 *X161 X160
Unit no.
Response
code
4-22 DM AREA WRITE
Writes data to the DM area, starting from the specified word. Writing is done
word by word. If the Program Memory is in an EPROM chip, or if the write enable
switch is set to OFF, the the writing range extends up to DM 0999 only.
Command Format
@ W D
X101 X100
Unit no.
X103 X102 X101 X100 X161 X160
FCS CR
*
Beginning word
X163 X162 X161 X160X163 X162
Data for beginning
word
Data for second
word
Response Format
@ W D FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
DM AREA WRITE Section 4-22

84
4-23 FM AREA WRITE
Writes data to a single specified word, or to an entire file memory block.
Command Format
@ W F
X101 X100
Unit no.
X103 X102 X101 X100 X161 X160
FCS CR
*
Number of blocks Data type Beginning byte
X161 X160 X103 X102 X101 X100
Comments
per block
Only even numbers can be specified
(Multiply the number of the beginning
word by two)
If applicable
7 6 5 4 3 2 1 0
1: END block *
X163 X162
Write data
X161 X160 X163 X162
Write data
X161 X160
*The END block of the PC
program, or the last block.
Writes a single word, or a full block per com-
mand execution.
0 0 1....I/O data
0 1 0....PC program
0 1 1....Comments
0000 to 1999
Response Format
@ W F FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-24 PV WRITE
Writes PVs (present values) of timers/counters, starting from the specified timer/
counter.
Command Format
X101 X100 X103 X102 X101 X100
FCS CR
*
word
Data for second
word@ W CUnit no.
X103 X102 X101 X100 X103 X102 X101 X100
Response Format
@ W C
X101 X100
Response
code FCS CR
*X161 X160
Unit no.
PV WRITE Section 4-24

85
4-25 SV CHANGE 1
Changes the set value (constant only) of the specified timer/counter instruction.
Reads from the beginning of the program and therefore take up to 20 seconds to
produce a response. Refer also to 4-26 SV CHANGE 2 and 4-27 SV CHANGE 3.
Command Format
@ W # CRSet value FCS
*TIM/CNT Word addressUnit no.
X103 X102 X101 X100X101 X100
0 0 0 0
to
0 1 2 7
0 0 0 0
to
0 5 1 1
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
OR3 OR4OR1 OR2OP3 OP4OP1 OP2
0 0 0 0
to
9 9 9 9
C200HE, C1000H, and C2000H.
Response Format
@ W #
X101 X100
FCS CR
*X161 X160
Response
codeUnit no.
SV CHANGE 1 Section 4-25

86
4-26 SV CHANGE 2
Changes the set value (a constant, or data area and word) of the specified timer/
counter instruction. The instruction is specified by its program address. If the
program has more than 9,999 addresses, use SV CHANGE 3, described in the
next subsection.
Command Format
@ W $
X101 X100 X103 X102 X101 X100
FCS CR
*
Address
X101 X100X103 X102
TIM/CNT
Data area Set value
X103 X102 X101 X100
Unit no. Word address
0 0 0 0
to
0 1 2 7
0 0 0 0
to
0 5 1 1
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
D M : – :DM area. . .
OP1 OP2 OP3 OP4
OP1 OP2 OP3 OP4
C200HE, C1000H, and C2000H.
Response Format
@ W $
X101 X100
FCS CR
*X161 X160
Response
codeUnit no.

87
4-27 SV CHANGE 3
Changes the set value (a constant, or data area and word) of the specified in-
struction. The operation is similar to SV CHANGE 2, but SV CHANGE 3 can
change SVs at higher program addresses (up to 5 digits, note that the leftmost,
i.e., the sixth, address bit is always zero).
Command Format
@ W %
X101 X100 X105 X104 X103 X102
FCS CR
*
Address TIM/CNT
Data area Set value
X103 X102 X101 X100
X101 X100
Number
X103 X102 X101 X100
Unit no.
Always 0
0 0 0 0
to
0 1 2 7
0 0 0 0
to
0 5 1 1
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
D M : – :DM area. . .
OP1 OP2 OP3 OP4
OP1 OP2 OP3 OP4
C200HE, C1000H, and C2000H.
Response Format
@ W %
X101 X100
FCS CR
*X161 X160
Response
codeUnit no.

88
4-28 FORCED SET
Forced sets a bit in an IR, LR, HR, AR, or TC area. Bits need to be force set one at
a time.
Command Format
@ K S
X101 X100 X103 X102
Data area
C I O –...IR area
L R – –...LR area
H R – –...HR area
A R – –...AR area
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
X101 X100
BitWord
X101 X100
FCS CR
*
TC area
Unit no.
OP1 OP2 OP3 OP4
Response Format
@ K S FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-29 FORCED RESET
Force resets a bit in an IR, LR, HR, AR, or TC area. Bits can only be force reset
one at a time. If an attempt is made to simultaneously force reset more than one
bit, none of the bits will reset.
Command Format
@ K R
X101 X100
Unit no.Unit no.
X103 X102
Data area
X101 X100
BitWord
X101 X100
FCS CR
*
C I O –...IR area
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
TC area
OP1 OP2 OP3 OP4
FORCED RESET Section 4-29

89
87Response Format
@ K R FCS CR
*X161 X160
Response
codeUnit no.
X101 X100
4-30 MULTIPLE FORCED SET/RESET
(C200H, C200HS, C200HX, C200HG, C200HE, and Mini H-type only.) This
command force sets or resets bits in the IR, LR, HR, AR, or TC areas.
Command Format
@ F K
X101 X100 X103 X102
T I M –
T I M H
C N T –
C N T R
T T I M
X101 X100
Word
TC area
X160 X160 X160 X160
X160 X160
FCS CR
*
... 2 1 0
3 2 1 0
0 0 0 0....Ignored
0 0 1 0....Data “0”
0 0 1 1....Data “1”
0 1 0 0....Forced reset
0 1 0 1....Forced set
1 0 0 0....Forced set/reset clear
Data area
Bit 15 14 13 12
Forced set/reset/data clear
X160
Unit no.
OP1 OP2 OP3 OP4
Response Format
@ F K
X101 X100 X161 X160
FCS CR
*
Response
codeUnit no.
MULTIPLE FORCED SET/RESET Section 4-30

90
4-31 MULTIPLE FORCED SET/RESET STATUS READ
(C200H, C200HS, C200HX, C200HG, C200HE, and Mini H-type only.) Reads
the forced set or forced reset status of the PC to which the specified Host Link
Unit is mounted. When the operand is a timer/counter instruction (i.e., TIM(SP),
TIMH, CNT(SP), CNTR, or TTIM), only the operands and words being force set/
reset will be read.
Command Format
@ F R
X101 X100
FCS CR
*
Unit no.
Response Format
@ F R
Bit 15 14 13 12
X101 X100
X103 X102
Data area
X101 X100
Word
0P1 0P2 0P3 0P4
Forced set/reset status
0/1 0/1 0/1 0/1
1: Forced set/reset
0: Not forced set/reset
,0/1 0/1
Bit 1 0
Delineator Only when applicable
Data area
0P1 0P2 0P3 0P4
Word
X103 X102 X101 X100
C I O –...IR area
T I M –
T I M H
C N T –
C N T R
T T I M
TC area
X161 X160
Response
code
FCS CR
*
Unit no.
4-32 FORCED SET/RESET CANCEL
Cancels all forced set and forced reset bits (including those achieved via MULTI-
PLE FORCED SET/RESET for the C200H, C200HS, C200HX, C200HG,
C200HE, and Mini H-type).
Command Format
@ K C
X101 X100
FCS CR
*Unit no.
Response Format
FCS CR
*X161 X160
Response
code
X101 X100
@ K CUnit no.
FORCED SET/RESET CANCEL Section 4-32

91
4-33 PC MODEL READ
Reads the model type of the PC.
Command Format
X101 X100
@ M M FCS CR
*Unit no.
Response Format
@ M M
X101 X100 X161 X160
Response
code FCS CR
*X161 X160
PC model
codeUnit no.
0 1 C250 or P-type
0 2 C500
0 3 C120
1 0 C1000H
1 1 C2000H
1 2 C200H/HS/HX/HG/HE
4-34 DM HIGH-SPEED READ
(C1000H and C2000H only) Reads a fixed group of eight DM area words at
high-speed. The group of words to be read depends on the Host Link Unit and
the PC as follows:
Host Link Unit C1000H/C2000H
3G2A5-LK101-(P)EV1
3G2A5-LK201-EV1
Wd DM 0008 to 0015
C500-LK103(-P) Operating level 0 Wd DM 0008 to 0015
C500-LK203 Operating level 1 Wd DM 0000 to 0007
3G2A6-LK101-(P)EV1
3G2A6-LK201-EV1
3G2A6-LK202-EV1
Wd DM 0016 to 0023
Command Format
@ C RUnit no.
X101 X100
FCS CR
*
Response Format
@ C R
X101 X100
Unit no.
FCS CR
*
Data from word n
X163 X162 X161 X160
Data from word n+1
X163 X162 X161 X160
Response
code
X161 X160
Data from word n+7
X163 X162 X161 X160 Word n: Fixed beginning word
Response time is not affected by the operating mode of the PC or the cycle time.
The response transmission begins less than 10 ms after the reception of the
command.
DM HIGH-SPEED READ Section 4-34

92
4-35 ABORT and INITIALIZE
The ABORT command is used to abort the process being performed by the Host
Link Unit and to then enable reception of the next command. The INITIALIZE
command initializes the transmission control procedure of all the PCs con-
nected to the host computer. Neither command receives a response.
A processing time of 100 ms is required between reception of the ABORT or INI-
TIALIZE commands, and reception of the next command. If INITIALIZE is used
in a single-link system, it will be regarded as undefined.
ABORT Command Format
X101 X100
@ X Z FCS CR
*Unit no.
INITIALIZE Command Format
@ CR
* *
4-36 TRANSMIT (C200HS/HX/HG/HE only)
The Host Link Unit will transmit the specified data sent from the PC via the TXD
(––) instruction in ASCII format. When the (TXD(––) instruction is executed in
the ladder diagram, data is transmitted to the host computer in the following for-
mat. Refer to the C200HS Operation Manual or C200HX/HG/HE Operation
Manual for further details on the TXD (––) instruction.
Response Format
X101 X100
FCS CR
*Data@ E XUnit no.
Data (122 ASCII characters max.)
The data (61 bits maximum) specified in the operands of the TXD (––) instruction
is converted into ASCII (122 characters maximum) and transmitted. There will
be no response required from the host computer for TXD (––) instruction.
4-37 Response to an Undefined Command
This response is sent if the Host Link Unit cannot read the command’s header
code, or if the specified command is not valid for the command level or model of
PC. If this response is received check the header code, command level, and PC
model, then execute the correct command.
Response Format
X101 X100
@ I C FCS CR
*Unit no.
Response to an Undefined Command Section 4-37

93
4-38 Response Indicating an Unprocessed Command
This response is sent when the Host Link Unit cannot process a command. The
type of error encountered by the Host Link Unit can be identified via the response
code.
Response Format
@
X101 X100 X161 X160
FCS CR
*Header code
Response
codeUnit no.
The header code varies according to the command which was sent. The head-
ers of some commands include subheader codes (e.g., I/O REGISTER, I/O
READ, and DM SIZE CHANGE).
4-39 PROGRAM READ
Transmits the contents of the PC program memory.
Command Format
X101 X100
@ R P FCS CR
*Unit no.
Response Format
@ R P
X101 X100
FCS CR
*
Program
X161 X160 X161 X160
Memory size
X161 X160
Response
codeUnit no.
4-40 I/O TABLE READ
Reads the registered I/O table and the actual I/O table (i.e., the I/O Unit configu-
ration connected to the PC).
Command Format
X101 X100
@ R I FCS CR
*Unit no.
Response Format
@ R I
X101 X100
Unit no. FCS CR
*
Registered
I/O table
X161 X160
Response
code
X161 X160 X161 X160
Actual I/O table
Registered I/O table Actual I/O table
930 1408 characters
336 358
C1000H/C2000H, C200H:
All others:
I/O TABLE READ Section 4-40

94
4-41 PROGRAM WRITE
Writes the received program into the PC program memory.
Command Format
FCS CR@ W P
Up to maximum memory capacity
X101 X100
Unit no.
*X161 X160 X161 X160
Program
Response Format
@ W P
X101 X100
FCS CR
*X161 X160
Response
codeUnit no.
4-42 I/O TABLE GENERATE
Corrects the registered I/O table to match the actual I/O table.
Command Format
@ M I
X101 X100
FCS CR
*
0 to 3 0 to 3 0 to 3 0 to 3 0 to 3 0 to 3 0 to 3 0 to 3
Unit no.
Applicable only to C1000H,C2000H
Remote
0
Rack
No.
Remote
3
Rack
No.
Remote
4
Rack
No.
Remote
5
Rack
No.
Remote
6
Rack
No.
Remote
7
Rack
No.
Rack number
Remote
1
Rack
No.
Remote
2
Rack
No.
Note When the Rack number is to remain unspecified, assign an ASCII character oth-
er than 0 to 3 to it.
Response Format
@ M I
X161 X160
Response
codeUnit no.
X101 X100
FCS CR
*
I/O TABLE GENERATE Section 4-42

95
4-43 I/O REGISTER
Registers the IR, LR, HR, AR, or TC area bit, or the DM word that is to be read via
I/O READ (described in the next subsection). Registered data is retained until
new data is registered, or the power is turned OFF.
Command Format
@ Q Q M R
TC area
X101 X100 X103 X102
Data area
X101 X100
Word
,
Data area
OP1 OP2 OP3 OP4
Word
X103 X102 X101 X100
,Operand
Subheader
code
Operand FCS CR
*OR1 OR2
Unit no.
C I O –....IR area
L R – –....LR area
A R – –....AR area
T I M –
T I M H
C N T –
C N T R
T M S –
T I M W
C N T W
T M H W
T T I M
D M – –....DM area
Delineator
OP1 OP2 OP3 OP4 OR1 OR2
Delineator
0 0
0 1
: :
1 5
C H
Bit no.
Word
setting
Setting Table
Data Area Word Operand Response
Bit IR 0000 to max. Wd 00 to 15 ON/OFF status of specified bit
LR 0000 to max. Wd 00 to 15 ON/OFF status of specified bit
HR 0000 to max. Wd 00 to 15 ON/OFF status of specified bit
AR 0000 to max. Wd 00 to 15 ON/OFF status of specified bit
TIM/CNT 0000 to max. Wd Anything other than “CH” ON/OFF status of specified bit
Wd IR 0000 to max. Wd “CH” Word contents
LR 0000 to max. Wd “CH” Word contents
HR 0000 to max. Wd “CH” Word contents
AR 0000 to max. Wd “CH” Word contents
TIM/CNT 0000 to max. Wd “CH” ON/OFF status of Completion Flag and PV
DM 0000 to max. Wd Any characters Word contents
The maximum number of data items for the C120 and C500 PCs is 140; and for
the C200H, C200HS, C200HX, C200HG, C200HE, C1000H, C2000H PCs the
maximum is 128. However, the C200H, C200HS, C200HX, C200HG, C200HE,
C1000H, C2000H PCs count the TC area word specification as two items.
The data is registered in the same sequence in which it was specified.
I/O REGISTER Section 4-43

96
Response Format
X101 X100
FCS CR
*X161 X160
Response
code
Subheader
code
@ Q Q M RUnit no.
4-44 I/O READ
Reads the data specified by I/O REGISTER.
Command Format
Subheader code
X101 X100
@ Q Q I R FCS CR
*Unit no.
Response Format
@ Q Q I R
,
Read word data
X163 X162 X161 X160
FCS CR
*
ON/
OFF
Present value
X103 X102 X101 X100X101 X100
Subheader code
,
ON/
OFF
, ,
Read bit status
0: OFF
1: ON
Delineator
X161 X160
Response
codeUnit no.
For TIM/CNT status read
I/O READ Section 4-44

97
4-45 Response Code List
A response code is returned with each response to a command to indicate the
results of executing the command. A response code of 00 indicates that the
command was completed normally. All other response codes indicate errors that
prevented proper command execution and tell something about the cause of the
error.
x161 x160 Description
0 0 Command completed normally.
0 1 Execution was not possible because the PC is in RUN mode. Change the PC mode.
0 2 Execution was not possible because the PC is in MONITOR mode. Change the PC mode.
0 3 Execution was not possible because PROM is mounted. Change the unit to RAM or EEPROM.
0 4 Address overflow (data overflow). Check the program.
0 B Execution was not possible because the PC is in PROGRAM mode. Change the PC mode.
0 C Execution was not possible because the PC is in DEBUG mode. Change the PC mode.
0 D Execution was not possible because the Host Link Unit’s keyswitch is set to LOCAL mode or because the
command was sent to a C2000H CPU that was on standby. Change the mode or send the command to
the active CPU.
1 0 Parity error.
1 1 Framing error (stop bit(s) not detected).
1 2 Overrun (the next command was received too soon).
1 3 FCS error (checksum error).
1 4 Command format error.
1 5 An incorrect data area designation was made for READ or WRITE.
1 6 Instruction not found.
1 8 Frame length error (maximum length exceeded).
1 9 Execution was not possible because of an unexecutable error clear, memory error, EEPROM write dis-
abled, etc.
2 0 I/O table generation was not possible (unrecognized Remote I/O Unit, word overflow, duplicated word
allocation).
2 1 An error occurred in the PC’s CPU.
2 2 The specified Memory Unit does not exist.
2 3 The specified Memory Unit is write-protected.
A 0 Aborted due to parity error in transmit data.
A 1 Aborted due to framing error in transmit data.
A 2 Aborted due to overrun in transmit data.
A 3 Aborted due to FCS (checksum) error in transmit data.
A 4 Aborted due to format error in transmit data.
A 5 Aborted due to entry number data error in transmit data.
A 8 Aborted due to frame length error in transmit data.
B 0 Not executable because the program area is not 16 kbytes.
Other Remove any possible causes of noise and resend the command.
Response Code List Section 4-45

98
4-46 Communications Examples
The following are examples of commands from the host computer (first line) and
the responses that would be given by the Host Link Unit (second line). The ar-
rows indicate the transfer of the right to transmit.
Reading Data from Multiple PC Words (Wd IR 04 to 06) (Normal Completion)
@ 1 0 R R 0 0 0 4 0 0 0 3 4 6
FCS
@ 1 0 R R 0 0 F E D C B A 9 8 7 6 5 4 4 7
Data in Wd 04 FCSData in Wd 05 Data in Wd 06
* CR
* CR
Wd 9000 Specified by Mistake in a DM AREA WRITE Command
@ 1 0 W D 9 0 0 0 A B C D 5 F
@ 1 0 W D 1 5 5 6
FCS
FCS
* CR
* CR
Header Code Destroyed During ERROR READ Operation
* CR@ 1 0
(M)(F)
* CR@ 1 0 I C 4 B
FCS
(Communication Error)
Communications Examples Section 4-46

99
Writing Data into PC Words (“0123” to Wd DM 400 and “FEDC” to Wd DM 401) and Confirming with
DM AREA READ.
FCS
@ 1 0 R D 0 4 0 0 0 0 0 2 5 1
@ 1 0 W D 0 0 5 2
@ 1 0 W D 0 4 0 0 0 1 2 3 F E D C 5 2
@ 1 0 R D 0 0 0 1 2 3 F E D C 5 3
FCS
FCS
FCS
* CR
* CR
* CR
* CR
Communications Examples Section 4-46

101
SECTION 5
Error Processing
This section describes errors that can occur in a computer-linked system employing one or more Host Link Units and how to
remedy them.
5-1 Development of an Error-processing Program 102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2 Error Control 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2-1 Invalid Processing 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2-2 Process Interruption 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2-3 Time Monitoring 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2-4 Retries 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-3 Example Host Computer Program 104. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-4 Troubleshooting 105. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

102
5-1 Development of an Error-processing Program
Errors that occur in Host Link systems are classified into the following three cate-
gories:
1, 2, 3... 1. Errors indicated by the Host Link Unit (see 5-4 Troubleshooting).
2. Errors processed by the PC (see the Restart and Error Flags sub-section
for each group of models in Section 2 Host Link Unit Characteristics).
3. Errors processed by the host computer (see 5-2 Error Control, 3-2 Commu-
nications Protocol, and all of Section 4 Commands and Responses, espe-
cially 4-35 ABORT and INITIALIZE, and 4-45 Response Code List).
Programs to monitor communication times and error handling need to be devel-
oped on the host computer. Be sure that these include processes that can re-
spond appropriately to errors and other abnormalities from the PC by taking into
consideration the kinds of errors described in the sections listed above. An ex-
ample of the logic processes that need to be considered is given in the in the
following flow-chart.
expired?
Response?
ERROR?
Process
Send command.
Tries=n?
Error processing
Start timer.
Next command.
Time
Tries=m?
Timeout
response.
processing
N
Y
Y N
N
Y
Y
N
N
Y
Input command.
Development of an Error-processing Program Section 5-1

103
5-2 Error Control
The host computer is responsible for ensuring system recovery after errors oc-
cur in the Host Link Unit.
The Host Link Unit runs the following checks to detect errors:
1, 2, 3... 1. Parity check
2. Framing check
3. Overrun check
4. Format check
5. Entry data check (The start word, read word, etc., in the command format.)
6. Frame Checksum (An Exclusive OR check is performed on all command or
response data, from the unit number to the end of the text.)
Of the above commands, 1 to 3 are performed on a character by character basis.
Checks 4 to 6, however, are performed on each block (frame).
Transmit data in a multiple-link system is checked by means of a parity check
and a Frame Checksum (FCS). The FCS check is not performed in single-link
systems.
5-2-1 Invalid Processing
If the Host Link Unit detects an error in a single-frame command or the first frame
of a command block, it will regard the command as invalid. The command will not
be processed and, after the terminator is received, an error response will be sent
to the host computer. (For details of the error response, refer to 4-38 Response
Indicating an Unprocessed Command.
5-2-2 Process Interruption
If the Host Link Unit detects an error in an intermediate frame, the commands up
to that point will be processed normally. Those following the erroneous frame,
however, will not be processed. After the Host Link Unit has received the termi-
nator of the erroneous block, it responds with a response code that informs the
host computer of the process interruption. (For details, refer to 4-45 Response
Code List.)
5-2-3 Time Monitoring
If the Host Link Unit does not receive a delimiter or terminator, it cannot send a
response to the host computer. Similarly, if the computer does not receive a deli-
miter or terminator, it cannot transmit further commands to the Host Link Unit. To
allow transmission to alternate smoothly between the computer and the Host
Link Unit, the process times need to be monitored. It is therefore necessary to
have a time-monitoring program on the host computer side. Its purpose is to initi-
ate remedial action if the right to transmit is not transferred quickly enough.
5-2-4 Retries
An error response will be returned to the originating device if the Host Link Unit
detects any communications line data that has been destroyed (e.g., by noise).
If, however, the Unit number has also been lost, no response will be made at all.
It is therefore necessary to have response monitoring and retry processing in the
host computer to check for error responses.
Error Control Section 5-2

104
5-3 Example Host Computer Program
This example program causes arbitrary data to be written from the host comput-
er to DM 0001. A timer is included to retry transmission if the timer times out. An
error message is displayed after 3 time outs.
• OMRON FC-986 Host Computer
Host Link Unit:
C200H-LK101-PV1/LK201-V1/LK202-V1
3G2A5-LK101-(P)EV1/LK201-EV1/LK103(-P)
C500-LK203
3G2A6-LK101-(P)EV1/LK201-EV1/LK202-EV1
10 OPEN ”CQM1:E37NN” AS #1 Opens RS-232C. ............
20 NG=0:I=0:CNT=0
30 INPUT ”TEST DATA INPUT-----”;TD$ Inputs test data...
40 TC$=”@00WD0001”
50 TC$=TC$+TD$
60 GOSUM *FCSSET Calculates FCS.. ........................
70 TXD$=T$+FCS$+”*”+CHR$(13)
80 PRINT ”TXD$=”;TXD$
90 PRINT #1,TXD$; Transmission. ......................
100 IF LOC(1)<>0 GOTO 140 Determines whether data was received.. .............
110 CNT=CNT+1
120 IF CNT=1000 GOTO 1000 The value of CNT determines the timer setting.. .............
130 GOTO 100
140 INPUT #1,RXD$
150 R$=MID$(RXD$,6,2)
160 IF R$<>”00” GOTO 2000 Determines whether communications were completed normally.. .............
170 PRINT ”RXD$=”;RXD$+” OK”
180 GOTO 20
1000 REM *****TIME UP*****
1005 CNT=0
1020 ER$(NG)=”TIME UP”
1025 NG=NG+1
1030 IF NG=3 GOTO 3000 Sets 3 retries.. ................
1040 GOTO 80
2000 REM *****ERROR RESPONSE****
2020 ER$(NG)=RXD$+” NG”
2025 NG=NG+1
2030 IF NG=3 GOTO 3000 Sets 3 retries.. ................
2040 GOTO 80
3000 REM *****ERROR MESSAGE*****
3010 PRINT ”AN ERROR OCCURRED”
3020 PRINT ”RXD$–1=”;ER$(0)
3030 PRINT ”RXD$–2=”;ER$(1)
3040 PRINT ”RXD$–3=”;ER$(2)
3050 GOTO 20
4000 REM *****FCS CALCULATION*****
4010 *FCSSET
4020 L=LEN(T$)
4030 A=0
4040 FOR J=1 TO L
4050 TJ$=MID$(T$,J,1)
4060 A=ASC(TJ$) XOR A
4070 NEXT J
4080 FCS$=HEX$(A)
Example Host Computer Program Section 5-3

105
4090 IF LEN(FCS$)=1 THEN FCS$=”0”+FCS$
4100 RETURN
5-4 Troubleshooting
The following troubleshooting guide outlines the basic steps for remedying the
errors most likely to occur when using Host Link Units.
Problem Possible Cause Remedy Reference
RUN indicator does not
light. (When power is
applied to the Host
Link Unit, and the reset
is released, the indica-
tor should illuminate.)
Power is not applied to the PC.
Faulty contact in the connector between
the PC and the Host Link Unit.
PC is resetting the Host Link Unit.
Host Link Unit is defective.
Apply power to the PC.
Check and repair connections.
Turn the PC OFF, then ON. If
necessary, check the PC for an error
or abnormal reset.
Replace the Host Link Unit.
RCV indicator does not
blink. (When a signal is
input at the receive
connector, the indicator
should blink regardless
of the nature of the sig-
nal.)
No signal is being output form the host
computer.
The signal from the host computer is not
reaching the Host Link Unit.
The indicator circuit is defective.
Check the program and output of the
host computer.
Check the wiring:
• Cable not connected?
• Cable damaged?
• Cable incorrectly connected?
• Faulty contact in connector?
If the signal is being transmitted and
received normally, the Host Link Unit
is faulty and needs to be replaced.
Sections 1
and 2
XMT indicator does not
illuminate after the
RCV indicator. (If the
Unit number on the
computer side matches
that of the Host Link
Unit, the Host Link Unit
receives the termina-
tor, the CTS signal
then goes ON, and the
Host Link Unit sends
data irrespective of its
nature.)
The unit numbers of the computer and the
Host Link Unit do not match.
The Host Link Unit is not receiving a termi-
nator.
The signal is ignored because the Host
Link Unit cannot correctly read it.
• Transmission speeds of the host comput-
er and the Host Link Unit do not match.
• Incorrect wiring.
• Incorrect setting for the termination resis-
tance.
Parities or transmission codes don’t match.
Error in operating level setting.
Check the unit number settings.
Check whether the host computer is
outputting a terminator.
Check the settings of the Host Link
Unit and the Link Adapter.
Check the wiring for the CTS signal.
Check the parity or transmission
code settings.
Check the operating level settings.
Section 2
Section 1
Section 2
ERR indicator illumi-
nates.
Parity error (even parity).
Framing error.
Overrun error.
Occurrence of momentary power failure.
Send correct data. If a momentary
power failure occurs, both the PC
and the Host Link Unit are reset and
initialized. The ERRor indicator will
turn off.
Sections 2
and 3
Although the XMT indi-
cator illuminates, the
Host Link Unit cannot
send a response to the
host computer.
Operation error on the host computer side.
• I/O channel processing error.
• Program error.
The correct signal is not reaching the host
computer.
• Cable damage.
• Incorrect cable wiring.
• Faulty contact in connector.
--- Section 2
RUN
indicator
blinking.
Error in-
dicator
not lit.
Error in unit number, transmission speed,
command level, parity, or transmission
code setting.
Correct the setting and restart the
Host Link Unit.
Section 2
(C200H-
LK101-PV1/
LK201-V1/
LK202-V1
only)
Error in-
dicator
lit.
Error detected between the Host Link Unit
and CPU.
Turn power off and then back on.
Replace the Host Link Unit.
Troubleshooting Section 5-4

107
Appendix A
Standard Models
Product Description Model Number
Host Link Unit C200H Rack-mounting (two per PC) (APF/PCF/H-PCF) C200H-LK101-PV1
C200H-LK201-V1
C200H-LK202-V1
C500 Rack-mounting (one per PC) 3G2A5-LK101-PEV1
3G2A5-LK101-EV1
3G2A5-LK201-EV1
C500 Rack-mounting (two per PC) (APF/PCF/H-PCF) C500-LK103-P
C500-LK103
C500-LK203
CPU-mounting (APF/PCF/H-PCF) 3G2A6-LK101-PEV1
3G2A6-LK101-EV1
3G2A6-LK201-EV1
3G2A6-LK202-EV1
Link Adapter RS-422 (3 connectors) 3G2A9-AL001
Optical (PCF/H-PCF) (3 connectors) 3G2A9-AL002-E
Optical (APF/PCF/H-PCF) (3 connectors) 3G2A9-AL002-PE
Optical (PCF/H-PCF), RS-232C, RS-422 (1 connector each) 3G2A9-AL004-E
Optical (APF/PCF/H-PCF), RS-232C, RS-422 (1 connector each) 3G2A9-AL004-PE
Optical (PCF/H-PCF), optical (AGF) (1 connector each) 3G2A9-AL005-E
Optical (APF/PCF/H-PCF), optical (AGF) (1 connector each) 3G2A9-AL005-PE
Optical (PCF/H-PCF) (1 connector), optical (AGF) (2 connectors) 3G2A9-AL006-E
Optical (APF/PCF/H-PCF) (1 connector), optical (AGF) (2 connec-
tors)
3G2A9-AL006-PE
Optical Interface
(Used to interface C500-LK203, 3G2A5-LK201-EV1, and 3G2A6-LK201-EV1 Host Link Units.)
Optical Interface RS-232C to optical converter Z3RN-A-5
Optical Fiber Cable 1, 5, 10, 20, 30, 50, 100, 200, 400, or 500 m. (Replace “j” in model number
with the desired cable length)
Z3F2-4DjM
AC Adapter For Optical Interface power supply.
One required for C500-LK203; two for 3G2A5-LK201-EV1 or 3G2A6-LK201-EV1
Host Link Units.
Z3GP-01
Connecting Cable
RS-422 and RS-232C connecting cables must be provided by the user.
I/O Cables
RS-422 and RS-232C connecting cables must be provided by the user.
Type Connector Connector cover Maker
RS-232C XM2A-2501 XM2S-2511 OMRON
DB-25P DB-C2-J9 JAE
RS-422 XM2A-0901 XM2S-0911 OMRON
DE-9E DE-C1-J6 JAE

Standard Models Appendix A
108
Plastic Optical Fiber Cable
Host Link Units with the suffix -P in the model number can be extended up to 20 m. The optical connector of
the 3G5A2-PF002 must supplied by the user.
Plastic optical fiber cable Cable only (without optical connector). Order in multiples
of 5 m (from 5 to 100 m), or in lengths of 200 m or 500 m.
3G5A2-PF002
Optical connector A 2 Optical connectors (brown).
For plastic optical fiber cable 8 to 20 m long.
3G5A2-CO001
Optical connector B 2 Optical connectors (black).
For plastic optical fiber cable 8 to 20 m long.
3G5A2-CO002
Plastic optical fiber set 1 m cable with connector ‘A’ attached. 3G5A2-PF101
Hard-clad Plastic Optical Fiber (H-PCF)
Hard-clad plastic optical fiber Two-core optical cord type. Length: 1,000 m; color: black S3200-HBCB103
(H-PCF) Two-core optical cord type. Length: 10 m; color: black S3200-HBCB101
Two-core optical cord type. Length: 50 m; color: black S3200-HBCB501
Without tension member type (for fit). Length: 10 m; color: orange S3200-HCCO101N
Without tension member type (for fit). Length: 50 m; color: orange S3200-HCCO102N
Without tension member type (for fit). Length: 100 m;
color: orange
S3200-HCCO501N
Without tension member type (for fit). Length: 500 m;
color: orange
S3200-HCCO502N
Without tension member type (for fit) Length: 1,000 m;
color: orange
S3200-HCCO103N
With tension member type (for fit). Length: 10 m; color: black S3200-HCCB101
With tension member type (for fit) Length: 50 m; color: black S3200-HCCB501
With tension member type (for fit). Length: 1,000 m; color: black S3200-HCCB103
With tension member type (for fit). Length: 10 m; color: orange S3200-HCCO101
With tension member type (for fit) Length: 1,000 m; color: orange S3200-HCCO103
Optical connector SYSMAC BUS or SYSMAC WAY connector S3200-COCH82
Optical power tester SYSMAC BUS or SYSMAC WAY optical characteristics measure-
ment power tester
S3200-CAT2820
Head set SYSMAC BUS or SYSMAC WAY optical power tester head set S3200-CAT2822
Master fiber set SYSMAC BUS or SYSMAC WAY optical power tester master
fiber
S3200-CAT2821
In the case of SYSMAC WAY and SYSMAC BUS, the maximum available
length between units is 200 m.
Note

Appendix AStandard Models
109
Plastic-clad Optical Fiber Cable
Host Link Units with the suffix -P in the model number can be extended up to 200 m by using plastic-clad opti-
cal fiber cable. Those without the suffix -P in the model number can be extended up to 800 m.
Cable Type Description Operating Environment Model Number
Indoor 0.1 m, with connector Operating temperature: –10o to 70oC 3G5A2-OF011
1 m, with connector 3G5A2-OF101
Indoor/outdoor 1 to 500 m, with connector
(order in multiples of 1 m)
Operating temperature: –10o to 70oC 3G5A2-OF002
501 to 800 m, with connector
(order in multiples of 1 m)
Operating temperature: 0o to 55oC
(Do not expose to direct sunlight)
Since the optical fiber cable cannot be spliced as easily as ordinary cables
when damaged or extended, be sure to install an adequate length. The cable
lengths above do not include connectors.
Crystal Fiber Cable (AGF)
Crystal fiber cable is not available from OMRON. It must be obtained from an alternative supplier.
Note

111
Appendix B
Specifications
Communications
Communications 2-fiber, half duplex: -LK10j models
4-wire, half duplex: -LK20j models
Synchronization Start/stop: 1 stop bit (JIS) or 2 bits (ASCII)
Transmission
speed
300, 600, 1,200, 2,400, 4,800, 9,600, or 19,200 bps (switch-selectable)
Character code ASCII (7 bits) or JIS (8 bits)
Error check Parity and FCS
Interface* Optical fiber: -LK10j models
RS-232C, RS-422: -LK20j models
*Model numbers indicate the maximum transmission distance as given in the following tables.
Transmission Distance
Optical Fiber Cables
Model Number APF H-PCF PCF
C200H-LK101-PV1 20 m 100 m 200 m
3G2A5-LK101-PEV1 20 m 100 m 200 m
3G2A6-LK101-PEV1 20 m 100 m 200 m
C500-LK103-P 20 m 100 m 200 m
3G2A5-LK101-EV1 Cannot be connected 200 m 800 m
3G2A6-LK101-EV1 Cannot be connected 200 m 800 m
C500-LK103 Cannot be connected 200 m 800 m
Wire Cables
Model Number Interface Transmission Distance
C200H-LK202-V1 RS-422 10 m/branch (500 m total*)
C200H-LK201-V1 RS-232C 15 m
3G2A5-LK201-EV1 RS-232C 15 m
C500-LK203 RS-422 10 m/branch (500 m total*)
3G2A6-LK201-EV1 RS-232C 15 m
3G2A6-LK202-EV1 RS-422 10 m/branch (500 m total*)
*Total in the system.
Weight
C200H-LK101-PV1
C200H-LK201-V1
C200H-LK202-V1
400 g max.
3G2A5-LK101-(P)EV1
3G2A5-LK201-EV1
C500-LK103(-P)
C500-LK203
800 g max.
3G2A6-LK101-(P)EV1
3G2A6-LK201-EV1
3G2A6-LK202-EV1
600 g max.

Specifications Appendix B
112
Power Consumption
C200H-LK101-PV1
C200H-LK201-V1*
C200H-LK202-V1
0.25 A max. at 5 VDC
3G2A5-LK101-(P)EV1
3G2A5-LK201-EV1
C500-LK103(-P)
C500-LK203*
3G2A6-LK101-(P)EV1
3G2A6-LK201-EV1
3G2A6-LK202-EV1
1 A max. at 5 VDC
*Internal power consumption increases by 0.1 A when using the Z3RN-A-5.
Host Link Unit Dimensions
C200H
All C200H Units have dimensions as given below.
** Including Connector
* Including backplane
ÉÉ
ÉÉ
ÉÉÉÉ
ÉÉ
ÉÉ
ÉÉ
ÉÉÉÉ
ÉÉ
117*
100.5
130
35
Approx. 160**
Approx. 130**

Appendix BSpecifications
113
C500 (3G2A5)
The dimensions for C500 (3G2A5) Units are as given below.
250
** Including Backplane and connector
* Including Backplane
Approx. 100*
93
34.5
ÉÉ
ÉÉ
ÉÉ
ÉÉÉÉ
ÉÉ
ÉÉ
ÉÉÉÉ
ÉÉ
ÉÉ
ÉÉ
ÉÉ
ÉÉ
ÉÉ
Backplane
Approx. 165**
C120 (3G2A6)
The dimensions for C120 (3G2A6) CPU-mounting Units are as detailed in the following diagrams.
CPU

114
Link Adapter
The following gives the specifications for Link Adapters suitable for use with the Host Link Units. Care should
be taken to to choose a Link Adapter with the appropriate connections for the Units in the System. Other Link
Adapters may be included in the System in association with other types of Host Link Units (refer to the appli-
cable Host Link Manual or Link Adapter Manual).
Link Adapter Connection Supply voltage Operating volt-
age range
Power Con-
sumption
Weight
3G2A9-AL001 RS-422
RS-422RS-422
Not required --- --- 250 g
max.
3G2A9-AL002-PE Optical Fiber (APF/PCF/H-PCF)
Optical Fiber
(APF/PCF/
H-PCF)
Optical Fiber
(APF/PCF/
H-PCF)
100/200 VAC or
12 to 24 VAC/DC
85 to 132
/170 to 264 VAC or
10.2 to
26.4 VAC/DC
10 VA max. 900 g
max.
3G2A9-AL002-E Optical Fiber (PCF/H-PCF)
Optical Fiber
(PCF/
H-PCF)
Optical Fiber
(PCF/
H-PCF)
3G2A9-AL004-PE
Optical Fiber
(APF/PCF/
H-PCF)
RS-232C
RS-422 110 to 120 VAC/
220 to 240 VAC
94 to 132 VAC
187 to 264 VAC
10 VA max. 1 kg max.
3G2A9-AL004-E
Optical Fiber
(PCF/H-PCF) RS-232C
RS-422
3G2A9-AL005-PE Optical Fiber (APF/PCF/H-PCF)
Optical fiber
(AGF)
100/200 VAC or
12 to 24 VAC/DC
85 to 132
/170 to 264 VAC
or 10.2 to
26.4 VAC/DC
10 VA max. 1.5 kg
max.
3G2A9-AL005-E Optical Fiber (PCF/H-PCF)
Optical fiber
(AGF)
3G2A9-AL006-PE Optical Fiber (AGF)
Optical Fiber
(AGF)
Optical Fiber
(APF/PCF/
H-PCF)
100/200 VAC or
12 to 24 VAC/DC
85 to 132
/170 to 264 VAC
or 10.2 to
26.4 VAC/DC
10 VA max. 1.5 kg
max.
3G2A9-AL006-E Optical Fiber (AGF)
Optical Fiber
(AGF)
Optical Fiber
(PCF/
H-PCF)

115
3G2A9-AL001 Link Adapter
Dimensions
63
77
87
74.6 58
20.5
Approx. 100
Four, 3.5 dia.
Cable Wiring
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9
RS-422 Link Adapter 3G2A9-AL001
Applicable Connector
Connector Cover Maker
XM2A-0901 XM2S-0911 OMRON
DE-9P DE-C1-J6 JAE
Three RS-422 connectors are included with the 3G2A9-AL001.

116
3G2A9-AL002-(P)E Link Adapter
Dimensions
63
Approx. 140
150
164
178
43
101
100VAC
200VAC
4.5
Fuse
AC power
supply
Repeater
input
Auxiliary power supply
in case of power failure
Power
supply Auxiliary
power supply
12 to
24 VAC/VDC
Main line
Branch line
Main line
Main line optical
connector
Branch line
optical
connector
Main line optical
connector
LG FG Repeater
input
Mounting Holes
10 dia.
7
Internal Configuration
Power
supply
LG
FG
5 V
0 V
100 VACFuse
Optical
/Electrical
convertor
Optical
/Electrical
convertor
Optical
/Electrical
convertor
Switching
circuit
N2
N1
H
Ground (100 Ω or less)
200 VAC
AC power supply
12 to 24 VAC/VDC
Main signal line (APF/PCF/H-PCF) Main signal line (APF/PCF/H-PCF)Branch line (APF/PCF/H-PCF)
Repeater input
Link Adapter 3G2A9-AL002-(P)E
Always short circuit the repeater input terminals.
Power Supply Connection
100 V 200 V
← Ground power line
← Live power line ← Live power line
The fuse is located on the common side of the power supply, so connect the live AC power line (HOT LINE) to
the common terminal.

!
!
117
to terminal blocks.
Installing the Link Adapter
Use the Link Adapter with a supply of either 100/200 VAC or 12 to 24 VDC/VAC power.
Short circuit the repeater input terminals.
When installing the Link Adapter anywhere it could come into contact with people, be sure to set the Link
Adapter up so that the terminal block won’t be touched accidentally.
Cable Length
Cable 3G2A9-AL002-PE 3G2A9-AL002-E
APF 20 m Not available
H-PCF 100 m 200 m
PCF 200 m 800 m
Note 1. Always short circuit the repeater input terminals. The Unit will not operate
unless these terminals are shorted.
2. Always cap unused Optical Connectors. If the connectors are not capped,
ambient light interference can enter the Optical Fiber Cable and cause
transmission errors.
Dimensions
63
Approx. 140
160
174
188
120
52.5
RS232C RS422
POWER
FUSE 0.3A
200 VAC
Fuse Terminal block
LG FG
100
VAC
4.5
Mounting Holes
10 dia.
7
0 V
Exter-
nal
CTS
ON
OFF
Termi-
nator
to terminal blocks.

!
118
Transmission
2
3
4
5
6
7
8
20
1
SD
RD
RS
CS
DR
SG
CD
ER
FG
5
6
1
3
7
9
SDB
RDA
RDB
SG
FG
SDA
0 V 0 V
RS-232C
RS-422
0 V
LG
FG
N2
N1
H
5 V
24 V
Fuse
OR
/switching
circuit
200 VAC
100 VAC
External
CTS
Switching
0 V
Reception
AC power supply
CTS (CS) Switching
Set to 0 V when the CTS (Clear-To-Send) signal will usually be ON. Set to External when the signal is re-
ceived externally.
Termination Resistance Setting
Set to ON to connect the internal termination resistance (220 Ω ) and set to OFF to disconnect the internal
termination resistance.
Power Supply Connection
100 V 200 V
← Live power line ← Live power line
The fuse is located on the common side of the power supply, so connect the live AC power line (HOT LINE) to
the common terminal.
to terminal blocks.
When installing the Link Adapter anywhere it could come into contact with people, be sure to set the Link
Adapter up so that the terminal block won’t be touched accidentally.
Never use the Unit when the Terminal Block Cover is off. Be sure that the Terminal Block Cover is securely
attached.

119
Cable Length
H-PCF 100 m 200 m
PCF 200 m 800 m
Always cap unused Optical Connectors. If the connectors are not capped,
ambient light interference can enter the Optical Fiber Cable and cause trans-
mission errors.
Dimensions
110
47.5
153
164
178
63
Approx. 140
4.5
7
10 dia.
FUSE 0.1A
Wiring
Branch lines
Power
Reception Transmission
Mounting Holes
Internal circuit
Power
supply
5 V
0 V
Transmission Reception Reception
Fuse
LG
FG
100 VAC
Branch lines
(APF/PCF/H-PCF)
To SYSMAC PC
To Link Adapter
Wiring
(AGF)
AC power supply
200 VAC
12 to 24 VAC/VDC
Transmission
Note

!
120
to terminal blocks.
Use FC connectors for the AGF cables.
Connect the AGF cables correctly to the transmission and reception terminals.
Branch lines Wiring
Fuse 0.1A
Power
Cable Length (Max.)
H-PCF 100 m 200 m
PCF 200 m 800 m
AGF 3 km 3 km
Dimensions
110
47.5
153
164
178
63
Approx. 140
Fuse 0.1A
Power
Auxiliary power
Wiring
Branch lines
4.5
10 dia.
7
Mounting Holes
Wiring
Repeater
input
supply

!
121
Power
supply
5 V
0 V
Transmission Reception Reception Transmission
Fuse
LG
FG
100 VAC
Branch lines
(APF/PCF/H-PCF)
To SYSMAC PC
To Link
Adapter
Wiring
(AGF)
AC power
supply
200 VAC
Auxiliary
power
supply
12 to 24
VAC/VDC
Ground
(100 Ω or
less)
TransmissionReception
Wiring
(AGF)
Switching circuit
To Link
Adapter
Repeater
input
to terminal blocks.
Short circuit the repeater input terminals.
Use FC connectors for the AGF cables.
Connect the AGF cables correctly to the transmission and reception terminals.
Fuse
Power
Branch lines Wiring
Reception TransmissionReception Transmission
Wiring
Transmission
Reception Reception
Transmission
Auxiliary power
Repeater
input
supply
Cable Length (Max.)
H-PCF 100 m 200 m
PCF 200 m 800 m
AGF 3 km 3 km

123
Appendix C
ASCII Conversions
This appendix gives data conversions for ASCII characters. The decimal, binary and hexadecimal equivalents
are given. Refer to Appendix D for conversions between binary, hexadecimal, binary-coded hexadecimal, and
decimal data, up to 32dec.
Extended ASCII to Binary and Hexadecimal
The following table gives the conversions for the standard ASCII character set to both binary and hexadeci-
mal. In the Programmable Controller, all ASCII data is stored in it’s hexadecimal equivalent.
Bits 0 to 3 Bits 4 to 7
BIN 0000 0001 0010 0011 0100 0101 0110 0111 1010 1011 1100 1101 1110 1111
HEX 0 1 2 3 4 5 6 7 A B C D E F
0000 0 NUL DLE Space
0 @ P ` p 0 @ P ` p
0001 1 SOH DC1 ! 1 A Q a q ! 1 A Q a q
0010 2 STX DC2 " 2 B R b r " 2 B R b r
0011 3 ETX DC3 # 3 C S c s # 3 C S c s
0100 4 EOT DC4 $ 4 D T d t $ 4 D T d t
0101 5 ENQ NAK % 5 E U e u % 5 E U e u
0110 6 ACK SYN & 6 F V f v & 6 F V f v
0111 7 BEL ETB ' 7 G W g w ' 7 G W g w
1000 8 BS CAN ( 8 H X h x ( 8 H X h x
1001 9 HT EM ) 9 I Y i y ) 9 I Y i y
1010 A LF SUB * : J Z j z * : J Z j z
1011 B VT ESC + ; K [ k { + ; K [ k {
1100 C FF FS , < L l | , < L l |
1101 D CR GS Ć = M ] m } Ć = M ] m }
1110 E S0 RS . > N ^ n « . > N ^ n
1111 F S1 US / ? O _ o ~ / ? O _ o ~

ASCII Conversions Appendix C
124
ASCII to Decimal
The following table gives the decimal equivalents of the range of English language ASCII characters. The Pro-
grammable Controller stores ASCII data in hexadecimal form. Care should be taken when inputting ASCII
data in equivalent forms.
ASCII Decimal ASCII Decimal ASCII Decimal ASCII Decimal ASCII Decimal ASCII Decimal
Space 32 0 48 @ 64 P 80 ‘ 96 p 112
! 33 1 49 A 65 Q 81 a 97 q 113
” 34 2 50 B 66 R 82 b 98 r 114
# 35 3 51 C 67 S 83 c 99 s 115
$ 36 4 52 D 68 T 84 d 100 t 116
% 37 5 53 E 69 U 85 e 101 u 117
& 38 6 54 F 70 V 86 f 102 v 118
’ 39 7 55 G 71 W 87 g 103 w 119
( 40 8 56 H 72 X 88 h 104 x 120
) 41 9 57 I 73 Y 89 i 105 y 121
* 42 : 58 J 74 Z 90 j 106 z 122
+ 43 ; 59 K 75 [ 91 k 107 { 123
, 44 < 60 L 76 92 l 108 | 124
- 45 = 61 M 77 ] 93 m 109 } 125
. 46 > 62 N 78 ^ 94 n 110 « 126
/ 47 ? 63 O 79 _ 95 o 111 ~ 127

125
Appendix D
Data Conversion Table
Decimal BCD Hex Binary
00 0000 0000 00 0000 0000
01 0000 0001 01 0000 0001
02 0000 0010 02 0000 0010
03 0000 0011 03 0000 0011
04 0000 0100 04 0000 0100
05 0000 0101 05 0000 0101
06 0000 0110 06 0000 0110
07 0000 0111 07 0000 0111
08 0000 1000 08 0000 1000
09 0000 1001 09 0000 1001
10 0001 0000 0A 0000 1010
11 0001 0001 0B 0000 1011
12 0001 0010 0C 0000 1100
13 0001 0011 0D 0000 1101
14 0001 0100 0E 0000 1110
15 0001 0101 0F 0000 1111
16 0001 0110 10 0001 0000
17 0001 0111 11 0001 0001
18 0001 1000 12 0001 0010
19 0001 1001 13 0001 0011
20 0010 0000 14 0001 0100
21 0010 0001 15 0001 0101
22 0010 0010 16 0001 0110
23 0010 0011 17 0001 0111
24 0010 0100 18 0001 1000
25 0010 0101 19 0001 1001
26 0010 0110 1A 0001 1010
27 0010 0111 1B 0001 1011
28 0010 1000 1C 0001 1100
29 0010 1001 1D 0001 1101
30 0011 0000 1E 0001 1110
31 0011 0001 1F 0001 1111
32 0011 0010 20 0010 0000

127
Glossary
address The location in memory where data is stored. For data areas, an address
consists of a two-letter data area designation and a number that designate
the word and/or bit location. For the UM area, an address designates the in-
struction location (UM area); for the FM area, the block location (FM area),
etc.
AGF All-glass optical fiber cable, also known as crystal optical fiber cable.
allocation The process by which the PC assigns certain bits or words in memory for
various functions. This includes pairing I/O bits to I/O points on Units.
AND A logic operation whereby the result is true if and only if both premises are
true. In ladder-diagram programming the premises are usually ON/OFF
states of bits or the logical combination of such states called execution condi-
tions.
APF Acronym for all-plastic optical fiber cable.
AR area A PC data area allocated to flags, control bits, and word bits.
arithmetic shift A shift operation wherein the carry flag is included in the shift.
ASCII Short for American Standard Code for Information Interchange. ASCII is
used to code characters for output to printers and other external devices.
ASCII Unit An Intelligent I/O Unit used to program in BASIC. When connected to an
NSU on a Net Link System, commands can be sent to other nodes.
Backplane A base onto which Units are mounted to form a Rack. Backplanes provide a
series of connectors for these Units along with wiring to connect them to the
CPU. Backplanes also provide connectors used to connect them to other
Backplanes. In some Systems, different Backplanes are used for different
Racks; in other Systems, Racks differ only according to the Units mounted to
them.
BCD Short for binary-coded decimal.
BCD calculation An arithmetic calculation that uses numbers expressed in binary-coded deci-
mal.
binary A number system where all numbers are expressed to the base 2, i.e., any
number can be written using only 1’s or 2’s. Each group of four binary bits is
equivalent to one hexadecimal digit.
binary calculation An arithmetic calculation that uses numbers expressed in binary.
binary-coded decimal A system used to represent numbers so that each four binary bits is numeri-
cally equivalent to one decimal digit.
bit A binary digit; hence a unit of data in binary notation. The smallest unit of
information that can be electronically stored in a PC. The status of a bit is
either ON or OFF. Different bits at particular addresses are allocated to spe-
cial purposes, such as holding the status input from external devices, while
other bits are available for general use in programming.

Glossary
128
bit address The location in memory where a bit of data is stored. A bit address must
specify (sometimes by default) the data area and word that is being ad-
dressed as well as the number of the bit.
bit designator An operand that is used to designate the bit or bits of a word to be used by
an instruction.
bit number A number that indicates the location of a bit within a word. Bit 00 is the right-
most (least-significant) bit; bit 15 is the leftmost (most-significant) bit.
block Block can refer to one of three aspects of PC operation: a block in the FM
area, a block instruction (program), or a logic block. A block in the FM is the
unit used to transfer data to and from the File Memory Unit and equals 128
words. Refer to block instruction, block program, and logic block for defini-
tions of these.
block instruction A special class of instruction used within ladder-diagram programming to al-
low flowchart-like coding, which is often difficult to write with ladder diagrams.
Function codes for block instructions are indicated between pointed paren-
theses <like this>.
block program A section of program written within a ladder diagram but based on block in-
structions. Block programs can also contain some, but not all, of the lad-
der-diagram instructions.
buffer A temporary storage space for data in a computerized device.
building-block PC A PC that is constructed from individual components, or “building blocks.”
With building-block PCs, there is no one Unit that is independently identifi-
able as a PC. The PC is rather a functional assembly of components.
bus bar The line leading down the left and sometimes right side of a ladder diagram.
Instruction execution proceeds down the bus bar, which is the starting point
for all instruction lines.
call A process by which instruction execution shifts from the main program to a
subroutine. The subroutine may be called by an instruction or by an interrupt.
carry flag A flag that is used with arithmetic operations to hold a carry from an addition
or multiplication operation, or to indicate that the result is negative in a sub-
traction operation. The carry flag is also used with certain types of shift oper-
ations.
clock pulse A pulse available at a certain bit in memory for use in timing operations. Vari-
ous clock pulses are available with different pulse widths.
clock pulse bit A bit in memory that supplies a pulse that can be used to time operations.
Various clock pulse bits are available with different pulse widths, and there-
fore different frequencies.
condition An message placed in an instruction line to direct the way in which the termi-
nal instructions, on the right side, are to be executed. Each condition is as-
signed to a bit in memory that determines its status. The status of the bit as-
signed to each condition determines, in turn, the execution condition for each
instruction up to a terminal instruction on the right side of the ladder diagram.

Glossary
129
constant An operand for which the actual numeric value is specified by the user, and
which is then stored in a particular address in the data memory.
control bit A bit in a memory area that is set either through the program or via a Pro-
gramming Device to achieve a specific purpose, e.g., a Restart bit is turned
ON and OFF to restart a Unit.
Control System All of the hardware and software components used to control other devices.
A Control System includes the PC System, the PC programs, and all I/O de-
vices that are used to control or obtain feedback from the controlled system.
controlled system The devices that are being controlled by a PC System.
control signal A signal sent from the PC to effect the operation of the controlled system.
counter Either a dedicated number of digits or words in memory used to count the
number of times a specific process has occurred or a location in memory ac-
cessed through a TC bit and used to count the number of times the status of
a bit or an execution condition has changed from OFF to ON.
CPU An acronym for central processing unit. In a PC System, the CPU executes
the program, processes I/O signals, communicates with external devices,
etc.
CPU Backplane A Backplane used to create a CPU Rack.
CPU Rack Part of a building-block PC, the CPU Rack contains the CPU, a power sup-
ply, and other Units. With most PCs, the CPU Rack is the only Rack that pro-
vides linkable slots.
crystal optical fiber cable See AGF.
CTS An acronym for clear-to-send, a signal used in communications between
electronic devices to indicate that the receiver is ready to accept incoming
data.
cycle The process used to execute a ladder-diagram program. The program is ex-
amined sequentially from start to finish and each instruction is executed in
turn based on execution conditions.
cycle time The time required for a single cycle of the ladder-diagram program.
data area An area in the PC’s memory that is designed to hold a specific type of data,
e.g., the LR area is designed to hold common data in a PC Link System.
Memory areas that hold programs are not considered data areas.
data area boundary The highest address available in a data area. When designating an operand
that requires multiple words, it is necessary that the highest address in the
data area is not exceeded.
data sharing An aspect of PC Link Systems and of Data Links in Net Link Systems in
which common data areas or common data words are created between two
or more PCs.
debug A process by which a draft program is corrected until it operates as intended.
Debugging includes both removal of syntax errors, as well as fine-tuning of
timing and coordination of control operations.

Glossary
130
decimal A number system where all numbers are expressed to the base 10. Although
in a PC all data is ultimately stored in binary form, four binary bits are often
used to represent one decimal digit, via a system called binary-coded deci-
mal.
decrement Decreasing a numeric value.
default A value assumed and automatically set by the PC when a specific value is
not input by the user. Many devices will assume such default conditions upon
the application of power.
definer A number used as an operand for an instruction but that serves to define the
instruction itself rather that the data on which the instruction is to operate.
Definers include jump numbers, subroutine numbers, etc.
delimiter A carriage return (CR) indicating the end of the current frame within a mul-
ti-frame block of information. A terminator indicates the end of the block.
destination The location where data in an instruction is to be placed, as opposed to the
location from which data is to be taken, for use in the instruction. The location
from which data is to be taken is called the source.
differentiated instruction An instruction that is executed only once each time its execution condition
goes from OFF to ON. Nondifferentiated instructions are executed each cycle
as long as the execution condition stays ON.
differentiation instruction An instruction used to ensure that the operand bit is never turned ON for
more than one cycle after the execution condition goes either from OFF to
ON for a Differentiate Up instruction or from ON to OFF for a Differentiate
Down instruction.
digit A unit of storage in memory that consists of four bits.
digit designator An operand that is used to designate the digit or digits of a word to be used
by an instruction.
distributed control An automation concept in which control of each portion of an automated sys-
tem is located near the devices actually being controlled, i.e., control is de-
centralized and ‘distributed’ over the system. Distributed control is a concept
basic to PC Systems.
DM area A data area used to hold word data. A word in the DM area cannot be ac-
cessed bit by bit.
download The process of transferring a program or data from a higher-level computer
to a lower-level computer or PC.
Duplex CPU A CPU arrangement available for a C2000H PC in which there is actually two
CPUs. Each of the CPUs holds the same program and the same data. One
of the CPUs is active and controls current PC operation; the other CPU
serves as a backup and takes over PC operation if the active CPU fails.
Duplex System A C2000H PC System that uses a Duplex CPU.
Duplex Unit The Unit that coordinates the CPU activities of a Duplex System.

Glossary
131
electrical noise Electrical ‘static’ that can disturb electronic communications. The ‘snow’ that
can appear on a TV screen is an example of the effects of electrical noise.
error code A numeric code output to indicate the existence, and something about the
nature, of an error. Some error codes are generated by the system; others
are defined in the program by the operator.
exclusive OR A logic operation whereby the result is true if one and only one of the prem-
ises is true. In ladder-diagram programming the premises are usually ON/
OFF states of bits, or the logical combination of such states, called execution
conditions.
exclusive NOR A logic operation whereby the result is true if and only if both of the premises
are true or both of the premises are false. In ladder-diagram programming
the premises are usually ON/OFF states of bits, or the logical combination of
such states, called execution conditions.
exection condition The ON or OFF status under which an instruction is executed. The execution
condition is determined by the logical combination of conditions on the same
instruction line and up to the instruction being executed.
execution time The time required for the CPU to execute either an individual instruction or
an entire program.
Expansion I/O Backplane A Backplane used to create an Expansion I/O Rack.
Expansion I/O Rack Part of a building-block PC, an Expansion I/O Rack is connected to either a
CPU Rack or another Expansion I/O Rack to increase the number of slots
available for mounting Units.
extended counter A counter created in a program that counts higher than any of the standard
counters provided by the individual instructions.
extended timer A timer created in a program that times longer than any of the standard tim-
ers provided by the individual instructions.
Factory Intelligent Terminal A programming device provided with advanced programming and debugging
capabilities to facilitate PC operation. The Factory Intelligent Terminal also
provides various interfaces for external devices, such as floppy disk drives.
fatal error An error that will stop PC operation and require correction before operation
can be continued.
FCS Acronym for Frame Checksum.
File Memory see FM area.
FIT Abbreviation for Factory Intelligent Terminal.
flag A dedicated bit in memory that is set by the system to indicate some type of
operating status. Some flags, such as the carry flag, can also be set by the
operator or program.
flicker bit A bit that is programmed to turn ON and OFF at a specific frequency.

Glossary
132
floating point decimal A decimal number expressed as a number between 0 and 1 (the mantissa)
multiplied by a power of 10, e.g., 0.538 x 10–5.
Floppy Disk Interface Unit A Unit used to interface a floppy disk drive to a PC so that programs and/or
data can be stored on floppy disks.
FM area A memory area located in a File Memory Unit used to store/backup programs
and/or data.
force reset The process of forcibly turning OFF a bit via a programming device. Bits are
usually turned OFF as a result of program execution.
force set The process of forcibly turning ON a bit via a programming device. Bits are
usually turned ON as a result of program execution.
Frame Checksum The result of exclusive ORing all data within the FCS calculation range. Used
to confirm that the correct data is transmitted.
function code A two-digit number used to input an instruction into the PC.
GPC Acronym for Graphic Programming Console.
A programming device provided with advanced programming and debugging
capabilities to facilitate PC operation. A Graphic Programming Console is
provided with a large display onto which ladder-diagram programs can be
written directly in ladder-diagram symbols for input into the PC without con-
version to mnemonic form.
hardware error An error originating in the hardware structure (electronic components) of the
PC, as opposed to a software error, which originates in software (i.e., pro-
grams).
hexadecimal A number system where all numbers are expressed to the base 16. Although
in a PC all data is ultimately stored in binary form, displays on and inputs
through Programming Devices are often expressed in hexadecimal to facili-
tate operation. Each group of four binary bits is numerically equivalent to one
hexadecimal digit.
Host Link System One or more host computers connected to one or more PCs through Host
Link Units so that the host computer can be used to transfer data to, and to
receive data from, the PC(s). Host Link Systems enable centralized manage-
ment and control of PC Systems.
Host Link Unit An interface used to connect a PC to a host computer in a Host Link System.
host computer A computer that is used to transfer data or programs to or receive data or
programs from a PC in a Host Link System. The host computer is used for
data management and overall system control. Host computers are generally
personal or business computers.
HR area A data area used to store and manipulate data, and to preserve data when
power to the PC is turned OFF.
increment Increasing a numeric value.
Graphic Programming
Console

Glossary
133
indirect address An address whose contents indicates another address. The contents of the
second address will be used as the operand. Indirect addressing is possible
in the DM area only.
initialization error An error that occurs either in hardware or software during the PC System
startup, i.e., during initialization.
initialize Part of the startup process whereby some memory areas are cleared, system
setup is checked, and default values are set.
input The signal coming from an external device into the PC. The term input is of-
ten used abstractly or collectively to refer to incoming signals.
input bit A bit in the IR area that is allocated to hold the status of an input.
input device An external device that sends signals into the PC System.
input point The point at which an input enters the PC System. Input points correspond
physically to terminals or connector pins.
input signal A change in the status of a connection entering the PC. Generally an input
signal is said to exist when, for example, a connection point goes from low to
high voltage or from a nonconductive to a conductive state.
instruction A direction given in the program that tells the PC of an action to be carried
out, and which data is to be used in carrying out the action. Instructions can
be used to simply turn a bit ON or OFF, or they can perform much more com-
plex actions, such as converting and/or transferring large blocks of data.
instruction block A group of instructions that is logically related in a ladder-diagram program.
Although any logically related group of instructions could be called an instruc-
tion block, the term is generally used to refer to blocks of instructions called
logic blocks that require logic block instructions to relate them to other in-
structions or logic blocks.
instruction execution time The time required to execute an instruction. The execution time for any one
instruction can vary with the execution conditions for the instruction and the
operands used within it.
instruction line A group of conditions that lie together on the same horizontal line of a ladder
diagram. Instruction lines can branch apart or join together to form instruction
blocks.
Intelligent I/O Unit A Unit, such as an ASCII Unit or Ladder Diagram I/O Unit, that is equipped
with its own CPU and can be programmed.
interface An interface is the conceptual boundary between systems or devices and
usually involves changes in the way the communicated data is represented.
Interface devices such as NSBs perform operations like changing the coding,
format, or speed of the data.
interlock A programming method used to treat a number of instructions as a group so
that the entire group can be reset together when individual execution is not
required. An interlocked program section is executed normally for an ON ex-
ecution condition and partially reset for an OFF execution condition.

Glossary
134
interrupt (signal) A signal that stops normal program execution and causes a subroutine to be
run.
Interrupt Input Unit A Rack-mounting Unit used to input external interrupts into a PC System.
inverse condition see normally closed condition.
I/O capacity The number of inputs and outputs that a PC is able to handle. This number
ranges from around one hundred for smaller PCs to two thousand for the
largest ones.
I/O Control Unit A Unit mounted to the CPU Rack in certain PCs to monitor and control I/O
points on Expansion I/O Units.
I/O devices The devices to which terminals on I/O Units, Special I/O Units, or Intelligent
I/O Units are connected. I/O devices may be either part of the Control Sys-
tem, if they function to help control other devices, or they may be part of the
controlled system.
I/O Interface Unit A Unit mounted to an Expansion I/O Rack in certain PCs to interface the Ex-
pansion I/O Rack to the CPU Rack.
I/O Link Created in an Optical Remote I/O System to enable input/output of one or
two IR words directly between PCs. The words are input/output between the
PC controlling the Master and a PC connected to the Remote I/O System
through an I/O Link Unit or an I/O Link Rack.
I/O Link Unit A Unit used with certain PCs to create an I/O Link in an Optical Remote I/O
System.
I/O point The place at which an input signal enters the PC System, or at which an out-
put signal leaves the PC System. In physical terms, I/O points correspond to
terminals or connector pins on a Unit; in terms of programming, an I/O points
correspond to I/O bits in the IR area.
I/O response time The time required for an output signal to be sent from the PC in response to
an input signal received from an external device.
I/O table A table created within the memory of the PC that lists the IR area words allo-
cated to each Unit in the PC System. The I/O table can be created by, or mo-
dified from, a Programming Device.
I/O Unit The most basic type of Unit mounted to a backplane to create a Rack. I/O
Units include Input Units and Output Units, each of which is available in a
range of specifications. I/O Units do not include Special I/O Units, Link Units,
etc.
I/O word A word in the IR area that is allocated to a Unit in the PC System.
IR area A data area whose principal function is to hold the status of inputs coming
into the system and that of outputs that are to be set out of the system. Bits
and words in the IR that are used this way are called I/O bits and I/O words.
The remaining bits in the IR area are work bits.
JIS Acronym for Japanese Industrial Standards.

Glossary
135
jump A type of programming where execution moves directly from one point in a
program to another, without sequentially executing any instructions inbe-
tween. Jumps are usually conditional on an execution condition.
jump number A definer used with a jump that defines the points from and to which a jump
is to be made.
ladder diagram (program) A form of program arising out of relay-based control systems that uses cir-
cuit-type diagrams to represent the logic flow of programming instructions.
The appearance of the program is similar to a ladder, and thus the name.
ladder diagram symbol A symbol used in a ladder-diagram program.
ladder instruction An instruction that represents the ‘rung’ portion of a ladder-diagram program.
The other instructions in a ladder diagram fall along the right side of the dia-
gram and are called terminal instructions.
Ladder Support Software A software package that provides most of the functions of the Factory Intelli-
gent Terminal on an IBM AT, IBM XT, or compatible computer.
LAN An acronym for local area network.
leftmost (bit/word) The highest numbered bits of a group of bits, generally of an entire word, or
the highest numbered words of a group of words. These bits/words are often
called most-significant bits/words.
Link Adapter A Unit used to connect communications lines, either to branch the lines or to
convert between different types of cable. There are two types of Link
Adapter: Branching Link Adapters and Converting Link Adapters.
link A hardware or software connection formed between two Units. “Link” can
refer either to a part of the physical connection between two Units (e.g., opti-
cal links in Wired Remote I/O Systems) or a software connection created to
data existing at another location (Network Data Links).
linkable slot A slot on either a CPU or Expansion I/O Backplane to which a Link Unit can
be mounted. Backplanes differ in the slots to which Link Units can be
mounted.
Link System A system that includes one or more of the following systems: Remote I/O
System, PC Link System, Host Link System, or Net Link System.
Link Unit Any of the Units used to connect a PC to a Link System. These are Remote
I/O Units, I/O Link Units, PC Link Units, Host Link Units, and Net Link Units.
load The processes of copying data either from an external device or from a stor-
age area to an active portion of the system such as a display buffer. Also, an
output device connected to the PC is called a load.
local area network A network consisting of nodes or positions in a loop arrangement. Each node
can be any one of a number of devices, which can transfer data to and from
each other.
logic block A group of instructions that is logically related in a ladder-diagram program
and that requires logic block instructions to relate it to other instructions or
logic blocks.

Glossary
136
logic block instruction An instruction used to locally combine the execution condition resulting from
a logic block with a current execution condition. The current execution condi-
tion could be the result of a single condition, or of another logic block. AND
Load and OR Load are the two logic block instructions.
logic instruction Instructions used to logically combine the content of two words and output
the logical results to a specified result word. The logic instructions combine
all the same-numbered bits in the two words and output the result to the bit of
the same number in the specified result word.
loop A group of instructions that can be executed more than once in succession
(i.e., repeated) depending on an execution condition or bit status.
LR area A data area that is used in a PC Link System so that data can be transferred
between two or more PCs. If a PC Link System is not used, the LR area is
available for use as work bits.
LSS Abbreviation for Ladder Support Software.
main program All of a program except for the subroutines.
masking ‘Covering’ an interrupt signal so that the interrupt is not effective until the
mask is removed.
Master Short for Remote I/O Master Unit.
memory area Any of the areas in the PC used to hold data or programs.
mnemonic code A form of a ladder-diagram program that consists of a sequential list of the
instructions without using a ladder diagram. Mnemonic code is required to
input a program into a PC when using a Programming Console.
MONITOR mode A mode of PC operation in which normal program execution is possible, and
which allows modification of data held in memory. Used for monitoring or de-
bugging the PC.
most-significant (bit/word) See leftmost (bit/word).
NC input An input that is normally closed, i.e., the input signal is considered to be
present when the circuit connected to the input opens.
nest Programming one loop within another loop, programming a call to a subrou-
tine within another subroutine, or programming an IF-ELSE programming
section within another IF-ELSE section.
Net Link System An optical LAN formed from PCs connected through Net Link Units. A Net
Link System also normally contains nodes interfacing computers and other
peripheral devices. PCs in the Net Link System can pass data back and forth,
receive commands from any interfaced computer, and share any interfaced
peripheral device.
Net Link Unit The Unit used to connect PCs to a Net Link System. The full name is “SYS-
MAC Net Link Unit.”
Network Service Board A device with an interface to connect devices other than PCs to a Net Link
System.

Glossary
137
Network Service Unit A Unit that provides two interfaces to connect peripheral devices to a Net
Link System.
node One of the positions in a LAN. Each node incorporates a device that can
communicate with the devices at all of the other nodes. The device at a node
is identified by the node number. One loop of a Net Link System (OMRON’s
LAN) can consist of up to 126 nodes. Each node is occupied by a Net Link
Unit mounted to a PC or a device providing an interface to a computer or
other peripheral device.
NO input An input that is normally open, i.e., the input signal is considered to be pres-
ent when the circuit connected to the input closes.
noise interference Disturbances in signals caused by electrical noise.
nonfatal error A hardware or software error that produces a warning but does not stop the
PC from operating.
normally closed condition A condition that produces an ON execution condition when the bit assigned
to it is OFF, and an OFF execution condition when the bit assigned to it is
ON.
normally open condition A condition that produces an ON execution condition when the bit assigned
to it is ON, and an OFF execution condition when the bit assigned to it is
OFF.
NOT A logic operation which inverts the status of the operand. For example, AND
NOT indicates an AND operation with the opposite of the actual status of the
operand bit.
NSB An acronym for Network Service Board.
NSU An acronym for Network Service Unit.
OFF The status of an input or output when a signal is said not to be present. The
OFF state is generally represented by a low voltage or by non-conductivity,
but can be defined as the opposite of either.
OFF delay The delay between the time when a signal is switched OFF (e.g., by an input
device or PC) and the time when the signal reaches a state readable as an
OFF signal (i.e., as no signal) by a receiving party (e.g., output device or
PC).
ON The status of an input or output when a signal is said to be present. The ON
state is generally represented by a high voltage or by conductivity, but can be
defined as the opposite of either.
ON delay The delay between the time when an ON signal is initiated (e.g., by an input
device or PC) and the time when the signal reaches a state readable as an
ON signal by a receiving party (e.g., output device or PC).
one-shot bit A bit that is turned ON or OFF for a specified interval of time which is longer
than one cycle.
on-line removal Removing a Rack-mounted Unit for replacement or maintenance during PC
operation.

Glossary
138
operand Bit(s) or word(s) designated as the data to be used for an instruction. An op-
erand can be input as a constant expressing the actual numeric value to be
used or as an address to express the location in memory of the data to be
used.
operand bit A bit designated as an operand for an instruction.
operand word A word designated as an operand for an instruction.
operating error An error that occurs during actual PC operation as opposed to an initializa-
tion error, which occurs before actual operations can begin.
Optical I/O Unit A Unit that is connected in an Optical Remote I/O System to provide 8 I/O
points. Optical I/O Units are not mounted to a Rack.
Optical Slave Rack A Slave Rack connected through an Optical Remote I/O Slave Unit.
OR A logic operation whereby the result is true if either of two premises is true, or
if both are true. In ladder-diagram programming the premises are usually ON/
OFF states of bits or the logical combination of such states called execution
conditions.
output The signal sent from the PC to an external device. The term output is often
used abstractly or collectively to refer to outgoing signals.
output bit A bit in the IR area that is allocated to hold the status to be sent to an output
device.
output device An external device that receives signals from the PC System.
output point The point at which an output leaves the PC System. Output points corre-
spond physically to terminals or connector pins.
output signal A signal being sent to an external device. Generally an output signal is said
to exist when, for example, a connection point goes from low to high voltage
or from a nonconductive to a conductive state.
overseeing Part of the processing performed by the CPU that includes general tasks re-
quired to operate the PC.
overwrite Changing the content of a memory location so that the previous content is
lost.
parity Adjustment of the number of ON bits in a word or other unit of data so that
the total is always an even number or always an odd number. Parity is gener-
ally used to check the accuracy of data after being transmitted by confirming
that the number of ON bits is still even or still odd.
PC An acronym for Programmable Controller.
PCB An acronym for printed circuit board.
PC configuration The arrangement and interconnections of the Units that are put together to
form a functional PC.

Glossary
139
PCF Acronym for plastic-clad optical fiber cable.
PC Link System A system in which PCs are connected through PC Link Units to enable them
to share common data areas, i.e., each of the PCs writes to certain words in
the LR area and receives the data of the words written by all other PC Link
Units connected in series with it.
PC Link Unit The Unit used to connect PCs in a PC Link System.
PC System With building-block PCs, all of the Racks and independent Units connected
directly to them up to, but not including the I/O devices. The boundaries of a
PC System are the PC and the program in its CPU at the upper end; and the
I/O Units, Special I/O Units, Optical I/O Units, Remote Terminals, etc., at the
lower end.
peripheral device Devices connected to a PC System to aid in system operation. Peripheral
devices include printers, programming devices, external storage media, etc.
port A connector on a PC or computer that serves as a connection to an external
device.
present value The current value registered in a device at any instant during its operation.
Present value is abbreviated as PV.
printed circuit board A board onto which electrical circuits are printed for mounting into a comput-
er or electrical device.
Printer Interface Unit A Unit used to interface a printer so that ladder diagrams and other data can
be printed out.
program The list of instructions that tells the PC the sequence of control actions to be
carried out.
Programmable Controller A computerized device that can accept inputs from external devices and gen-
erate outputs to external devices according to a program held in memory.
Programmable Controllers are used to automate control of external devices.
Although single-component Programmable Controllers are available, build-
ing-block Programmable Controllers are constructed from separate compo-
nents. Such building-block Programmable Controllers are formed only when
enough of these separate components are assembled to form a functional
assembly, i.e., no one individual Unit is called a PC.
programmed alarm An alarm given as a result of execution of an instruction designed to gener-
ate the alarm in the program, as opposed to one generated by the system.
programmed error An error arising as a result of the execution of an instruction designed to gen-
erate the error in the program, as opposed to one generated by the system.
programmed message A message generated as a result of execution of an instruction designed to
generate the message in the program, as opposed to one generated by the
system.
Programming Console The simplest form or programming device available for a PC. Programming
Consoles are available both as hand-held models and as CPU-mounting
models.

Glossary
140
Programming Device A peripheral device used to input a program into a PC or to alter or monitor a
program already held in the PC. There are dedicated programming devices,
such as Programming Consoles, and there are non-dedicated devices, such
as a host computer.
PROGRAM mode A mode of operation that allows inputting and debugging of programs to be
carried out, but that does not permit normal execution of the program.
PROM Writer A peripheral device used to write programs and other data into a ROM for
permanent storage and application.
prompt A message or symbol that appears on a display to request input from the op-
erator.
PV Acronym for present value.
Rack An assembly of various Units on a Backplane that forms a functional unit in a
building-block PC System. Racks include CPU Racks, Expansion I/O Racks,
I/O Racks, and Slave Racks.
refresh The process of updating output status sent to external devices so that it
agrees with the status of output bits held in memory and of updating input
bits in memory so that they agree with the status of inputs from external de-
vices.
relay-based control The forerunner of PCs. In relay-based control, groups of relays are intercon-
nected to form control circuits. In a PC, these are replaced by programmable
circuits.
Remote I/O Master Unit The Unit in a Remote I/O System through which signals are sent to all other
Remote I/O Units. The Remote I/O Master Unit is mounted either to a CPU
Rack or an Expansion I/O Rack connected to the CPU Rack. Remote I/O
Master Unit is generally abbreviated to Master.
Remote I/O Slave Unit A Unit mounted to a Backplane to form a Slave Rack. Remote I/O Slave Unit
is generally abbreviated to Slave. The operation of a Slave is controlled by a
Master.
Remote I/O System A system in which remote I/O points are controlled through a Master
mounted to a CPU Rack or an Expansion I/O Rack connected to the CPU
Rack.
Remote I/O Unit Any of the Units in a Remote I/O System. Remote I/O Units include Masters,
Slaves, Optical I/O Units, I/O Link Units, and Remote Terminals.
remote I/O word An I/O word allocated to a Unit in a Remote I/O System.
reset The process of turning a bit or signal OFF or of changing the present value of
a timer or counter to its set value or to zero.
retry The process whereby a device will re-transmit data which has resulted in an
error message from the receiving device.
return The process by which instruction execution shifts from a subroutine back to
the main program (usually the point from which the subroutine was called).

Glossary
141
reversible counter A counter that can be both incremented and decremented depending on the
specified conditions.
reversible shift register A shift register that can shift data in either direction depending on the speci-
fied conditions.
right-hand instruction Another term for terminal instruction.
rightmost (bit/word) The lowest numbered bits of a group of bits, generally of an entire word, or
the lowest numbered words of a group of words. These bits/words are often
called least-significant bits/words.
rotate register A shift register in which the data moved out from one end is placed back into
the shift register at the other end.
RUN mode The operating mode used by the PC for normal control operations.
scheduled interrupt An interrupt that is automatically generated by the system at a specific time
or program location specified by the operator. Scheduled interrupts result in
the execution of specific subroutines that can be used for instructions that
must be executed repeatedly for a specified period of time.
self diagnosis A process whereby the system checks its own operation and generates a
warning or error if an abnormality is discovered.
self-maintaining bit A bit that is programmed to maintain either an OFF or ON status until set or
reset by specified conditions.
servicing The process whereby the PC provides data to or receives data from external
devices or remote I/O Units, or otherwise handles data transactions for Link
Systems.
set The process of turning a bit or signal ON.
set value The value from which a decrementing counter starts counting down or to
which an incrementing counter counts up (i.e., the maximum count), or the
time from which or for which a timer starts timing. Set value is abbreviated
SV.
shift register One or more words in which data is shifted a specified number of units to the
right or left in bit, digit, or word units. In a rotate register, data shifted out one
end is shifted back into the other end. In other shift registers, new data (ei-
ther specified data, zero(s) or one(s)) is shifted into one end and the data
shifted out at the other end is lost.
Simplex CPU A C2000H PC that uses only a single CPU as opposed to a Duplex CPU.
This term is meaningless with other PCs, which are only available with sim-
plex operation.
Simplex System A C2000H PC System that uses a Simplex CPU.
Slave Short for Remote I/O Slave Unit.
Slave Rack A Rack containing a Remote I/O Slave Unit and controlled through a Remote
I/O Master Unit. Slave Racks are generally located away from the CPU Rack.

Glossary
142
slot A position on a Rack (Backplane) to which a Unit can be mounted.
software error An error that originates in a software program.
software protect A means of protecting data from being changed that uses software as op-
posed to a physical switch or other hardware setting.
source The location from which data is taken for use in an instruction, as opposed to
the location to which the result of an instruction is to be written. The latter is
called the destination.
Special I/O Unit A dedicated Unit that is designed for a specific purpose. Special I/O Units
include Position Control Units, High-speed Counter Units, Analog I/O Units,
etc.
SR area A data area in a PC used mainly for flags, control bits, and other information
provided about PC operation. The status of only certain SR bits may be con-
trolled by the operator, i.e., most SR bits can only be read.
subroutine A group of instructions placed after the main program and executed only if
called from the main program or activated by an interrupt.
subroutine number A definer used to identify the subroutine that a subroutine call or interrupt
activates.
SV Abbreviation for set value.
switching capacity The maximum voltage/current that a relay can safely switch on and off.
syntax error An error in the way in which a program is written. Syntax errors can include
‘spelling’ mistakes (i.e., a function code that does not exist), mistakes in
specifying operands within acceptable parameters (e.g., specifying write-
protected SR bits as a destination), and mistakes in actual application of in-
structions (e.g., a call to a subroutine that does not exist).
system configuration The arrangement in which Units in a system are connected.
system error An error generated by the system, as opposed to one resulting from execu-
tion of an instruction designed to generate an error.
system error message An error message generated by the system, as opposed to one resulting
from execution of an instruction designed to generate a message.
TC area A data area that can be used only for timers and counters. Each bit in the TC
area serves as the access point for the SV, PV, and Completion flag for the
timer or counter defined with that bit.
TC number A definer that corresponds to a bit in the TC area and used to define the bit
as either a timer or a counter.
terminal instruction An instruction placed on the right side of a ladder diagram that uses the final
execution conditions of an instruction line.
terminator The code comprising an asterisk and a carriage return (* CR) which indicates
the end of a block of data, whether it is a single-frame or multi-frame block.
Frames within a multi-frame block are separated by delimiters.

Glossary
143
timer A location in memory accessed through a TC bit and used to time down from
the timer’s set value. Timers are turned ON and reset according to their ex-
ecution conditions.
TM area A memory area used to store the results of a trace.
transmission distance The distance that a signal can be transmitted.
TR area A data area used to store execution conditions so that they can be reloaded
later for use with other instructions.
trace An operation whereby the program is executed and the resulting data is
stored in TM memory to enable step-by-step analysis and debugging.
transfer The process of moving data from one location to another within the PC, or
between the PC and external devices. When data is transferred, generally a
copy of the data is sent to the destination, i.e., the content of the source of
the transfer is not changed.
trigger address An address in the program that defines the beginning point for tracing. The
actual beginning point can be altered from the trigger by defining either a
positive or negative delay.
UM area The memory area used to hold the active program, i.e., the program that is
being currently executed.
Unit In OMRON PC terminology, the word Unit is capitalized to indicate any prod-
uct sold for a PC System. Though most of the names of these products end
with the word Unit, not all do, e.g., a Remote Terminal is referred to in a col-
lective sense as a Unit. Context generally makes any limitations of this word
clear.
unit number A number assigned to some Link Units and Special I/O Units to facilitate
identification when assigning words or other operating parameters to it.
watchdog timer A timer within the system that ensures that the cycle time stays within speci-
fied limits. When limits are reached, either warnings are given or PC opera-
tion is stopped depending on the particular limit that is reached.
Wired Slave Rack A Slave Rack connected through a Wired Remote I/O Slave Unit.
word A unit of data storage in memory that consists of 16 bits. All data areas con-
sists of words. Some data areas can be accessed only by words; others, by
either words or bits.
word address The location in memory where a word of data is stored. A word address must
specify (sometimes by default) the data area and the number of the word that
is being addressed.
word multiplier A value between 0 and 3 that is assigned to a Master in a Remote I/O Sys-
tem so that words can be allocated to non-Rack-mounting Units within the
System. The word setting made on the Unit is added to 32 times the word
multiplier to arrive at the actual word to be allocated.
work bit A bit in a work word.

Glossary
144
work word A word that can be used for data calculation or other manipulation in pro-
gramming, i.e., a ‘work space’ in memory. A large portion of the IR area is
always reserved for work words. Parts of other areas not required for special
purposes may also be used as work words, e.g., LR words not used in a PC
Link or Net Link System.

145
Index
A
ABORT, 92
applications, precautions, xiii
AR AREA READ, 74
AR AREA WRITE, 82
ASCII, data conversions
decimal, 124
to binary and hexadecimal, 123
B
baud rate
See also transmission speed
C200H, 25
binary data, 65
C
C120 (3G2A6), Host Link Units, dimensions, 113
C200H, Host Link Units, dimensions, 112
C200H Host Link Units, 24–32
C500 (3G2A5), Host Link Units, dimensions, 113
C500 and 3G2A5 Host Link Units, 33
caution sticker, 53
channel. See word
character code, 111
clear-to-send selector
3G2A6, 51
C200H, 27
C500/3G2A5, 37
clock settings
3G2A6, 50
C500/3G2A5, 36
command levels, 60
See also operating level
commands
ABORT, 92
AR AREA READ, 74
AR AREA WRITE, 82
communications examples, 98
DM AREA READ, 76
DM AREA WRITE, 83
DM HIGH-SPEED READ, 91
ERROR READ, 73
FM AREA WRITE, 84
FM DATA READ, 77
FM INDEX READ, 76
FORCED RESET, 88
FORCED SET, 88
FORCED SET/RESET CANCEL, 90
HR AREA READ, 74
HR AREA WRITE, 82
I/O READ, 96
I/O REGISTER, 95
I/O TABLE GENERATION, 94
I/O TABLE READ, 93
INITIALIZE, 92
IR AREA READ, 74
IR AREA WRITE, 81
LR AREA READ, 75
LR AREA WRITE, 82
MULTIPLE FORCED SET/RESET, 89
MULTIPLE FORCED SET/RESET STATUS READ, 90
PC MODEL READ, 91
PROGRAM READ, 93
PROGRAM WRITE, 94
PV READ, 77
PV WRITE, 84
STATUS READ, 72
STATUS WRITE, 81
SV CHANGE 1, 85
SV CHANGE 2, 86
SV CHANGE 3, 87
SV READ 1, 78
SV READ 2, 79
SV READ 3, 80
TC STATUS READ, 75
TC STATUS WRITE, 83
TEST, 72
TRANSMIT, 92
commands and responses, 71–99
table, 60
communications
conditions, 7
examples, 98
formats, 7
protocol, C200H, 67
communications errors
3G2A6, 54
C200H, 30
C500/3G2A5, 42
Connecting Cable, models, 107
connections, 3
hard-clad plastic optical fiber cable, 2
multiple-link, 15
shield wire to FG, RS-422, 17
shielded cable, 15
soldering, 16
unshielded cable, 16
connectors, RS–232C and RS–422, 15
Crystal Fiber Cable (AGF), models, 109
CTS selector
3G2A6, 51
C200H, 27
C500/3G2A5, 37
cycle time, 91

Index
146
D
data areas, keying in, 65
data conversion, table, 125
data flow
C200H, 29
C500/3G2A5, 39
test program example, 66
data representation
binary, 65
decimal, 65
hexadecimal, 65
decimal data, 65
delimiter, 72, 103
dimensions
Host Link Units, 112
C120 (3G2A6), 113
C200H, 112
C500 (3G2A5), 113
Link Adapters
3G2A9-AL001, 115
3G2A9-AL002-(P)E, 116
3G2A9-AL004-(P)E, 117
3G2A9-AL005-(P)E, 119
3G2A9-AL006-(P)E, 120
DM AREA READ, 76
DM AREA WRITE, 83
DM HIGH-SPEED READ, 91
E
error check, 111
error control, 103
error flag
3G2A6, 54
C200H, 31
C500/3G2A5, 43
error indicator
3G2A6, 54
C200H, 31
C500/3G2A5, 43
ERROR READ, 73
errors, 101–105
communications
3G2A6, 54
C200H, 30
C500/3G2A5, 42
error–processing program, 102
error-processing program, 102
invalid processing, 103
process interruption, 103
response codes, 97
transmission
3G2A6, 54
C200H, 31
C500/3G2A5, 43
CPU-mounting Host Link Units, 58
external appearance
3G2A6, 48
C200H, 24
C500/3G2A5, 33
F–H
fault diagnosis. See troubleshooting
File Memory AREA WRITE, 84
File Memory DATA READ, 77
File Memory INDEX READ, 76
FORCED RESET, 88
FORCED SET, 88
FORCED SET/RESET CANCEL, 90
Frame Checksum (FCS) calculation, 69, 103
program example, 69
Hard-clad Plastic Optical Fiber (H-PCF), models, 108
hexadecimal data, 65
host computer, example program, 104
host link, communications protocol, 62
Host Link Unit, MODE selector, C500/3G2A5, 36
Host Link Units
3G2A6, 48
CPU-mounting, 57
mounting, 57
removing, 57
dimensions, 112
models, 107
mounting, 6
HOST mode, C500/3G2A5, 36, 39
HR AREA READ, 74
HR AREA WRITE, 82
I
I/O Cable, models, 107
I/O port selector, C500/3G2A5, 37
I/O READ, 96
I/O REGISTER, 95
I/O response times
3G2A6, 55
C200H, 32
C500/3G2A5, 43
I/O TABLE GENERATION, 94
I/O TABLE READ, 93
indicators
C120 (3G2A6) Host Link Units, 51
C200H Host Link Units, 28
C500 (3G2A5) Host Link Units, 38
INITIALIZE, 92

Index
147
installation, precautions, xiii
interfaces, 7, 111
optical, 7
RS-232C, 8
RS-422, 11
invalid processing, 103
IR AREA READ, 74
IR AREA WRITE, 81
L–M
Link Adapter, 3, 4, 15
dimensions
3G2A9-AL001, 115
3G2A9-AL002-(P)E, 116
3G2A9-AL004-(P)E, 117
3G2A9-AL005-(P)E, 119
3G2A9-AL006-(P)E, 120
models, 107
specifications, 114
LOCAL mode, C500/3G2A5, 36, 38, 40
LR AREA READ, 75
LR AREA WRITE, 82
MODE selector, C500/3G2A5, 36
modes, C200H, 26
MONITOR mode
3G2A6, 52
C500/3G2A5, 39
MONITOR/NORMAL selector
3G2A6, 50, 52
C500/3G2A5, 36, 38
mounting Host Link Units, 6
MULTIPLE FORCED SET/RESET, 89
MULTIPLE FORCED SET/RESET STATUS READ, 90
multiple-link connections, 15
multiple-link multiple-level system, 5
multiple-link system, 2
N–O
noise tolerance, 14
nomenclature
3G2A6, 48
C200H, 24
C500/3G2A5, 33
NORMAL mode
3G2A6, 50
C500/3G2A5, 36
operating environment, precautions, xiii
operating level
3G2A6, 50
C500/3G2A5, 36
operating mode
3G2A6, 52
C200H, 28
C500/3G2A5, 38
optical fiber cables, transmission distance, 111
optical fiber connections
parallel multiple-link system, 4
serial multiple-link system, 3
optical fiber connectors, 3
Optical Interface, models, 107
P
parallel multiple-link system, 4
PC MODEL READ, 91
PC modes
HOST, C500/3G2A5, 39
LOCAL, C500/3G2A5, 38, 40
RUN
3G2A6, 53
C200H, 30
C500/3G2A5, 41
STOP
3G2A6, 52
C500/3G2A5, 39
Plastic Optical Fiber Cable, models, 108
Plastic-clad Optical Fiber Cable, 109
power consumption, 112
power supply selector
C200H, 27
C500/3G2A5, 37
precautions, xi
applications, xiii
general, xii
operating environment, xiii
safety, xii
process interruption, 103
PROGRAM READ, 93
PROGRAM WRITE, 94
programming, 59–69
protocol, host link communications, 62
PV READ, 77
PV WRITE, 84
R
reset switch, C500/3G2A5, 36
response
code list, 97
to an undefined command, 92
to an unprocessed command, 93
restart and error flags
3G2A6, 54

Index
148
C200H, 30
C500/3G2A5, 42
restart bit, C200H, 31
restart flag
3G2A6, 54
C500/3G2A5, 43
retries, 103
RUN mode
3G2A6, 53
C200H, 30
C500/3G2A5, 41
RUN start command
3G2A6, 53
C200H, 30
C500/3G2A5, 41
RUN/STOP selector
3G2A6, 52
C200H, 28
C500/3G2A5, 36, 38
S
safety precautions. See precautions
serial multiple-link system, 3
settings, host computer, 7
single-link system, 2
single-link/multiple link selector, C500/3G2A5, 36
single-link/multiple-link selector
3G2A6, 50
C200H, 27
soldering, 16
specifications
Host Link Units, 111
Link Adapters, 114
3G2A9-AL001, 115
3G2A9-AL002-(P)E, 116
3G2A9-AL004-(P)E, 117
3G2A9-AL005-(P)E, 119
3G2A9-AL006-(P)E, 120
STATUS READ, 72
STATUS WRITE, 81
SV CHANGE 1, 85
SV CHANGE 2, 86
SV CHANGE 3, 87
SV READ 1, 78
SV READ 2, 79
SV READ 3, 80
SW1
3G2A6, 49
C200H, 25
C500/3G2A5, 35
SW2
3G2A6, 50
C200H, 25
C500/3G2A5, 36
SW3, C200H, 25
SW4, 26
switch settings
3G2A6, 49–57
C200H, 25
C500/3G2A5, 35–47
CTS (CS) switching, 19
one-to-one connection, 20
one-to-N connection, 20
requirements, 19
synchronization, 111
synchronization selector
3G2A6, 50
C500/3G2A5, 36
system checks, 66
system examples, 2
single-link, 2
T–W
TC STATUS READ, 75
TC STATUS WRITE, 83
termination resistance
3G2A6, 51
C200H, 27
C500/3G2A5, 37
terminator, 72, 103
TEST, 72
test, system communications, 66
time monitoring, 103
transmission distance
optical fiber cables, 111
wire cables, 111
transmission error
3G2A6, 54
C200H, 31
C500/3G2A5, 43
transmission speed, 111
See also baud rate
C200H, 25
TRANSMIT, 92
troubleshooting, 105
undefined commands, 92
unprocessed commands, 93
weight, 111
wire cables, transmission distance, 111
wire connection
optical Units, 18
single-link system, 4
wire connectors, 3, 15

149
Revision History
A manual revision code appears as a suffix to the catalog number on the front cover of the manual.
Cat. No. W143-E1-6
Revision code
The following table outlines the changes made to the manual during each revision. Unless noted, page num-
ber refer to the previous version.
Revision code Date Revised content
2 March 1990 Converted to standard manual and page formats. The text was rewritten to give extra clarity.
Link Adapters section omitted.
The HR entry in table Level 1 of Section 3-4 now reads RH.
Section 3-6 I/O Response Times has been redrawn for greater clarity.
Appendix C has been split and the specifications for the accessories are now included in Appendix D.
3 April 1991 Layout of manual was restructured for greater clarity. Host Link Unit characteristics have been sepa-
rated according to Host Link Unit groups. Hard-clad plastic optical fiber added to page 18 and Appen-
dix B.
Page 6: Description of DIP switch pins added to C200H-LK201
Page 11: 1-3 Host Link Unit dimensions has been transferred to App B
Page 14: A single-link system need not be specified if the I/O Port Selector is set to RS-232C.
Page 15: The diagram in the Termination Resistance example has been changed.
Page 20: The Equipment Ready symbol has been changed to DTR and the pin no. for ST corrected
to 24.
Page 31: The data flow diagram for sending a RUN Start Command using 3G2A5 and 3G2A6 mod-
els has been corrected.
Page 35: No. of text characters for first and intermediate frames in a multiple-link system have been
corrected to 123 and 125 respectively.
Page 39: Names of the following commands have been changed:
PV AREA READ → PV READ
TC AREA READ → TC STATUS READ
DM AREA READ → Data Memory READ
DM AREA WRITE → Data Memory WRITE
TC AREA WRITE → TC STATUS WRITE
Page 40: Instructions applicable to Mini H-type PCs have been noted.
Pages 49-73: Command and response formats have been corrected and standardized. A Response
Format if Error Occurs has been added to TEST.
Page 5: C2000H-LK201 corrected to C200H-LK201.
Page 7: Table row headings corrected.
Page 93: Old C500 Host Link Units removed.
Page 95: C200-LK201 corrected to C200H-LK201 in 3rd table.
3A December 1992 Page 11: “For all but C500-LK203 and insulated types” added to 1-5-3 RS-422 Interface.
Page 87: Error Response Code List corrected.
Page 101: Model numbers 3G5A2-C0001 and 3G5A2-C0002 were corrected to 3G5A2-CO001 and
3G5A2-CO002 respectively.
Page 102: Optical fiber cutter removed from table.
4 February 1994 This manual has been extensively revised throughout all sections and appendices. Units C200H-
LK101-P and C200H-LK201/202 changed to C200H-LK101-PV1 and C200H-LK201-V1/202-V1 re-
spectively; the C200HS PC has been added and the C2000 PC has been removed throughout the
manual. The terms “scan” and “scan time” have been changed to “cycle” and “cycle time” throughout
this manual.
4A January 1995 Page 36: Text relating to the operating mode added after the second table.
Page 115: Switches shown on the right side of the dimensions diagram corrected.
5 August 1996 SYSMAC α C200HX/HG/HE added throughout the manual.
Pages 25, 26: The link type selector information corrected.
Page 87: Data for Forced Set/Reset Clear corrected to 1000.
Page 112: The table row containing AL004-PE/E corrected.
6 February 2000 Pages xii and xiii: Updated precautions.
Page 2: Added a note (***) to the table and CjjH (V1 models) to applicable PCs for 3G2A6.
Page 19, 20, 114, 116, 117, 119: Added wire and screw specifications and a caution for tightening
torque.
Page 113: Added a grounding line to the cable wiring illustration.

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