Plc & scada report 6

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Industrial
Training
Report
[AARMON TECH]
INDUSTRIAL AUTOMATION
AARMON TECH
21 Kumud Vihar, Above ESIC
Dispensary
Near Laxmi Sweets,Sector 3, Pratap
Nagar

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TABLE OF CONTENTS
CHAPTER 1.
INDUSTRIAL AUTOMATION……………………………………………………….01-05
1.1 INTRODUCTION……………………………………………………………...........01
1.2 INDUSTRIAL AUTOMATIONTOOLS……………………………………………02
1.2.1 PLC- PROGRAMMABLE LOGIC CONTROLLER…………………............03
1.2.2 SCADA- SUPERVISORY CONTROL AND DATAACQUISITION……….03
1.2.3 HMI- HUMAN MACHINE INTERFACE…………………………………….03
1.2.4 ANN- ARTIFICIAL NEURAL INTERFACE…………………………..…….04
1.2.5 DCS- DISTRIBUTED CONTROL SYSTEM…………………………….…..04
1.2.6 PAC- (PROGRAMMABLE AUTOMATION CONTROLLER)
INSTRUMENTATION MOTION CONTROL ROBOTICS…………….……04
1.3 ADVANTAGES OF AUTOMATION………………………………………………04
1.4 DISADVANTAGES OF AUTOMATION…………………………..………………04
1.5 LIMITATIONS OF AUTOMATION…………………………………………..……05
1.6 APPLICATIONS OF AUTOMATION………………………...……………………05
CHAPTER 2.
PLC (PROGRAMMABLE LOGIC CONTROLLER) ………...…………………….06-21
2.1 INTRODUCTION OF PLC……………………………………………………….…06
2.2 DEVELOPMENT AND HISTORY…………………………………………………07
2.3 FEATURES OF PLC……………………………………………………………...…09
2.3.1 HIGH RELIABILITY……………………………………………………….…09
2.3.2 FLEXIBILITY…………………………………………………………………09
2.3.3 QUALITY OF STRONG – EASY OPERATION…………………………..…09
2.3.4 EASY PROGRAMMINGAND MODIFICATION………………………...…09
2.3.5 LONGER LIFE……………………………………………………………...…10
2.3.6 VAST APPLICATIONS…………………………………………………….…10
2.4 ARCHITECTURE………………………………………………………..……….…10
2.4.1 CPU…………………………………………………………………………….11
2.4.2 THE BUSES………………………………………………………………...…13
2.4.3 MEMORY…………………………………………………………………..…14
2.4.4 INPUT/OUTPUT UNIT…………………………………………………….…14
2.5 SOURCINGAND SINKING……………………………………………………..…15
2.6 WORKINGOF PLC…………………………………………………………………15

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2.4.1 CONNECTION OF PLC………………………………………………………16
2.7 CLASSIFICATION OF PLC……………………………………...…………………18
2.7.1 ON BASIS OF I/O MODULES ……………………………………………….19
2.7.2 ON THE BASIS OF APPLICATION RANGE…………………….…………19
2.7.3 ON THE BASIS OF APPLICATION…………………………………………19
2.8 APPLICATIONS OF PLC……………………………………...……………………19
2.8.1 APPLICATIONS IN SECURITY………….………………………………….20
2.8.2 CONTROLLINGAPPLICATIONS…………………………...………………20
2.8.3 INDUSTRIAL APPLICATIONS………………………………...……………20
2.9 ADVANTAGES OF PLC……………………………………....……………………21
2.9.1 FLEXIBILITY………………………..…….………………………………….21
2.9.2 CORRECTINGERRORS…………………………………………..…………21
2.9.3 SPACE EFFICIENT……………………………………………...……………21
2.9.4 LOW COST……………………………………………………………………21
2.9.5 TESTING………………………………………………………...……….……21
2.9.6 VISUAL OBSERVATION………………………….…………………………21
2.9.7 PREDEFINED FUNCTION BLOCK…………….……………...……………21
2.10 DISADVANTAGES OF PLC…………………………...…………………………21
CHAPTER 3.
SCADA (SUPERVISORYCONTROL AND DATA ACQUISITION) …………….22-36
3.1 WHAT IS SCADA? …………………………………...……………………………22
3.2 FIELD WHERE SCADA CAN BE USED…………………………….……………22
3.2.1 MANUFACTURING…………………...….………………………………….22
3.2.2 BUILDING,FACILITIES AND ENVIRONMENT………………………..…22
3.2.3 ELECTRICAL POWER GENERATION,TRANSMISSION AND
DISTRIBUTION……………………………………………………….………23
3.2.4 WATER AND SEWAGE……………………...………………………………23
3.2.5 MASS TRANSIT………………………………………………………………23
3.2.6 TRAFFIC SIGNALS…………………………………………………..………23
3.3 HOW DOES SCADA WORK………………………………………….……………23
3.4 WHY SCADA? ……………………………………………………………………..24
3.5 ARCHITECTURE OF SCADA…………………………………………..…………24
3.5.1 FIRST GENERATION- “MONOLITHIC” ………………...…………………24
3.5.2 SECOND GENERATION- “DISTRIBUTED”.………………………………25
3.5.3 THIRD GENERATION- “NETWORKED” ……………………….…………25
3.6 COMPONENTS OF SCADA ……………………………..……………………….. 25

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3.6.1 A HUMAN MACHINE INTERFACE OR HMI ………………...……………24
3.6.2 SYSTEM CONCEPTS………………………………………………...………26
3.6.3 REMOTE TERMINAL UNITS (RTUs) ….…………………..………………26
3.6.4 PROGRAMMABLE LOGIC CONTROLLER (PLC)……………...…………26
3.6.5 SUPERVISORY STATION…………………………………………...………26
3.7 FEATURES AND THEIR FUNCTIONALITY…………………………..…………27
3.7.1 DYNAMIC PROCESS GRAPHIC………........................................................27
3.7.2 ALARM SUMMARY AND ALARM HISTORY………………….…………27
3.7.3 REAL TIME TREND AND HISTORICAL TIME TREND……………….…28
3.7.4 SECURITY (APPLICATION SECURITY) ………………………..…………28
3.7.5 DATABASE CONNECTIVITY………………………………………………30
3.7.6 DEVICE CONNECTIVITY……………………………………………...……30
3.7.7 SCRIPTS……………………………….………………………………………30
3.7.8 RECIPE MANAGEMENT……………….……………………………………30
3.7.9 NETWORKING…………………………………………………….…………31
3.7.10 DATA ACQUISITION……………………………………………….………31
3.7.11 OPERATOR INTERFACE………………..…………………………………31
3.8 DEVELOPERS OF SCADA………………………….…………………..…………31
3.9 WORKINGWITH INTOUCH SCADA SCRIPT………………………...…………32
3.10 COMPONENT OF SCADA (SENSOR) …………………………………..………33
3.10.1 WHAT ARE SENSORS? …………………………….……………...………33
3.11 APPLICATIONS OF SCADA…………………………………………..…………34
3.11.1 BUILDING MAINTENANCE………………………………………….……34
3.11.2 ENERGY…………………………………………………………..…………34
3.11.3 MANUFACTURING……………………………………………..……….…35
3.11.4 WATER AND WASTE WATER…………………………………….………35
3.11.5 HEALTHCARE………………………………………………………………35
3.11.6 PETROCHEMICAL……………………………………………….…………35
3.11.7 DIGITAL SIGNAGE SOLUTION……………………………...……………35
3.12 ADVANTAGES OF SCADA……………………………………….…..…………36
3.13 DISADVANTAGES OF SCADA…………………………………….....…………36
CHAPTER 4.
CONCLUSION……………………………………………………………….…………37-38

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FIGURE INDEX
FIGURE NO. FIGURE NAME PAGE NO.
2.1 PLC 06
2.2 BASIC PLC ARCHITECTURE 11
2.3 OPTOISOLATOR 14
2.4 SINKING AND SOURCING 15
2.5 CONTROL PANEL OF SCADA 22
2.6 WORKING OF SCADA 23
2.7 ARCHITECTURE OF SCADA 24

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CHAPTER 1
INDUSTRIAL AUTOMATION
1.1 INTRODUCTION
As the name suggest “Automation” means to perform automatic operations by means
of different kinds of machines.
Automation means self move “auto” and “mation”
Automation is the use of control systems and information technologies to reduce the
need for human work in the production of goods and services. In the scope of
industrialization, automation is a step beyond mechanization.
Automation or automatic control, is the use of various control systems for operating
equipment such as machinery, processes in factories, boilers and heat treating ovens,
switching in telephone networks, steering and stabilization of ships, aircraft and other
applications with minimal or reduced human intervention. Some processes have been
completely automated.
The biggest benefit of automation is that it saves labor, however, it is also used to save
energy and materials and to improve quality, accuracy and precision.
The term automation, inspired by the earlier word automatic (coming
from automaton), was not widely used before 1947, when General Motors established
the automation department.[1]
It was during this time that industry was rapidly
adopting feedback controllers, which were introduced in the 1930s
Automation has been achieved by various means including mechanical, hydraulic,
pneumatic, electrical, electronic and computers, usually in combination. Complicated
systems, such as modern factories, airplanes and ships typically use all these
combined techniques.
In the automation system we include PLC, SCADA, HMI, DRIVE and all industrial
sensors and motors

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The main component of an industrial automation system are-
□ Process Controller (People)
□ Control System(Technical System)
FIG 1.1: Industrial Automation Process
□ Computer and Communication System
□ Sensors
By combination of above all processes an industrial automation system is created
which can implement any kind of process.
1.2 INDUSTRIALAUTOMATION TOOLS
Current technology is unable to automate all the desired tasks, unpredictable
development costs. The research and development cost of automatic a process is
difficult to predict accurately beforehand. Since this cost can have a large impact on
profitability, it's possible to finish automating process only to discover that there's no
economic advantage in doing so. Initial costs are relatively high. The automation of a

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new product required a huge initial investment in comparison with the unit cost of the
product, although the cost of automation is spread in many product batches. The
automation of a plant required a great initial investment too, although this cost is
spread in the products to be produced. Automation tools different types automation
tools exist:
1.2.1 PLC - Programmable Logic Controller –
It is a digital computer used for automation of electromechanical process such as
control of machinery on the factory assembly lines, amusement rides, or lighting
fixtures PLCs are used in many industries and machines. Unlike general-purpose
computers, the PLC is designed for multiple inputs and output arrangements.
1.2.2 SCADA - Supervisory Control and Data Acquisition –
SCADA (supervisory control and data acquisition) is a type of industrial control
system (ICS). Industrial control system are computer controlled systems that monitor
and control industrial processes that exists in the physical world. SCADA systems
historically distinguish themselves from other ICS systems be being large scale
processes that can include multiple sites, and large distance.
1.2.3 HMI-Human Machine Interface-
Human Machine interface is the part of the machine that handles the Human-machine
interaction. Membrane Switches, Rubber Keypads and Touch screens are examples of
that part of the Human Machine interface which we can see and touch.

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1.2.4 ANN -Artificial neural network–
An artificial neural network is a computational simulation of a biological neural
network. These models mimic the real life behavior of neurons and the electrical
messages they produce between input (such as from the eyes or nerve endings in the
hand), processing by the brain and the final output from the brain (such as reacting to
light or from sensing touch or heat). There are other ANNs which are adaptive
systems used to model things such as environments and population.
1.2.5 DCS - Distributed Control System –
A distributed control system(DCS) refers to a control system usually of a
manufacturing system, process or any kind of dynamic system, in which the controller
elements are not in location (like a brain) but are distributed throughout the system
with each component sub-system controlled by one or more controllers. It is a
computerized control system used to control the production line in the industry.
1.2.6 PAC- (Programmable Automation Controller) Instrumentation Motion
control Robotics-
Programmable automation controller or PAC a relatively new name coined for small,
local control systems. The name is derived largely from the popular PLC or
Programmable Logic Controller. One major difference between the PLC and PAC is
the programming interface. Most PLCs are programmed in a graphical representation
of coils and contacts called Ladder Logic. Most of the PACs are programmed in a
modern programming language such as C or C++.
1.3 ADVANTAGES OF AUTMATION-
• Replacing human operators in tasks that involve hard physical or monotonous
work.
• Replacing humans in tasks done in dangerous environments.
• Performing tasks that are beyond human capabilities of size, weight, speed,
endurance, etc.
• Economy improvement: Automation may improve in economy of enterprises,
society or most of humanity.

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1.4 DISADVANTSGES OF AUTOMATION-
 Security threats vulnerability: An automated system may have a limited level
of intelligence, and is therefore more susceptible to committing errors of its
immediate scope of knowledge.
 Unpredictable/excessive development costs: the research and development
cost of automating a process may exceed the cost saved by the automation
itself.
 High initial cost: the automation of a new product or plant typically requires a
very large initial investment in comparison with the unit cost of the product,
although the cost of automation may be spread among many products and over
time.
1.5 LIMITATIONS OF AUTOMATION-
 Current technology is unable to automate all the desired tasks.
 As a process becomes increasingly automated, there is less labor to be saved
or quality improvement to be gained.
 Similar to the above, as more and more processes become automated, there
are fewer remaining non-automated processes.
1.6 APPLICATIONS OF AUTOMATION-
 Automated retail- food and drink, stores
 Automated mining
 Automated video surveillance
 Automated highway systems
 Automated waste management
 Automated manufacturing
 Home automation
 Industrial automation

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CHAPTER 2
PLC (Programmable Logical Controller)
2.1 INTRODUCTON OF PLC
A PROGRAMMABLE LOGIC CONTROLLER (PLC) is an industrial computer
control system that continuously monitors the state of input devices and make
decisions based upon a custom program to control the state of output devices. It is
designed for multiple inputs and output arrangements, extended temperature ranges,
immunity to electrical noise, and resistance to vibration and impact. Almost any
production process can greatly enhanced usingthis type of control system, the biggest
benefit in using a PLC is the ability to change and replicate the operation or process
while collecting and communicating vital information. Another advantage of a PLC is
that it is modular. i.e. you can mix and match the types of input and output devices to
best suit your application.
Fig.: 2.1 PLC

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2.2 DEVELOPMENT AND HISTORY
Before the PLC, control, sequencing, and safety interlock logic for manufacturing
automobiles was mainly composed of relays, cam timers, drum sequencers, and
dedicated closed-loop controllers. Since these could number in the hundreds or even
thousands, the process for updating such facilities for the yearly model change-
over was very time consuming and expensive, as electricians needed to individually
rewire the relays to change their operational characteristics.
Digital computers, being general-purpose programmable devices, were soon applied
to control of industrial processes. Early computers required specialist programmers,
and stringent operating environmental control for temperature, cleanliness, and power
quality. Using a general-purpose computer for process control required protecting the
computer from the plant floor conditions. An industrial control computer would have
several attributes: it would tolerate the shop-floor environment, it would support
discrete (bit-form) input and output in an easily extensible manner, it would not
require years of training to use, and it would permit its operation to be monitored. The
response time of any computer system must be fast enough to be useful for control;
the required speed varying according to the nature of the process.[1]
Since many
industrial processes have timescales easily addressed by millisecond response times,
modern (fast, small, reliable) electronics greatly facilitate building reliable controllers,
especially because performance can be traded off for reliability.
In 1968 GM Hydra-Matic (the automatic transmission division of General Motors
issued a request for proposals for an electronic replacement for hard-wired relay
systems based on a white paper written by engineer Edward R. Clark. The winning
proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC,
designated the 084 because it was Bedford Associates' eighty-fourth project, was the
result. Bedford Associates started a new company dedicated to developing,
manufacturing, selling, and servicing this new product: Modicon, which stood
for Modular Digital Controller. One of the people who worked on that project
was Dick Morley, who is considered to be the "father" of the PLC.[3]
The Modicon
brand was sold in 1977 to Gould Electronics, and later acquired by German
Company AEG and then by French Schneider Electric, the current owner.These PLCs

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were programmed in "ladder logic", which strongly resembles a schematic diagram of
relay logic.
This program notation was chosen to reduce training demands for the existing
technicians. Other early PLCs used a form of instruction list programming, based on a
stack-based logic solver.
Modern PLCs can be programmed in a variety of ways, from the relay-derived ladder
logic to programming languages such as specially adapted dialects of BASIC and C.
Another method is State Logic, a very high-level programming language designed to
program PLCs based on state transition diagrams.
Many early PLCs did not have accompanying programming terminals that were
capable of graphical representation of the logic, and so the logic was instead
represented as a series of logic expressions in some version of Boolean format, similar
to Boolean algebra. As programming terminals evolved, it became more common for
ladder logic to be used, for the aforementioned reasons and because it was a familiar
format used for electromechanical control panels. Newer formats such as State Logic
and Function Block (which is similar to the way logic is depicted when using digital
integrated logic circuits) exist, but they are still not as popular as ladder logic
In 1969 Gould Modicon developed the first PLC. Hardware CPU controller, with
logic instructions, 1K of memory and 128 I/O points
 1974 - Use of several processors within a PLC
 1976- Remote input/output systems introduced
 1977 - Microprocessors-based PLC introduced
 1980 - Intelligent I/O modules developed enhanced communications facilities.
 1983 - low-cost small PLC's introduced
 1985 on - Networking of all levels of PLC, computer and machine using SCADA
software.

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2.3 FEATURES OF PLC
PLC control system is that it regards PLC as control key component, utilize special
I/O module to form hardware of control system with a small amount of measurement
and peripheral circuit, to realize control to the whole system through programming.
2.3.1HIGH RELIABILITY
Strong anti-interference quality and very high reliability are the most important
features of PLC. In order to make PLC work stably in strong interferential
circumstance. Many techniques are applied in PLC. Software control instead of relay
control mode can decrease faults which are brought about by original electric contact
spot outside working badly. Industrial grade components made by advance processing
technology can resist interferences, and self-diagnosis measures of watchdog circuit
for protecting memory can improve performance of PLC greatly.
2.3.2FLEXIBILITY
There are several programming languages for PLC including ladder diagram, SFC,
STL, ST and so on. If operator can master only one of programming languages, he can
operate PLC well. Every who want to use PLC has a good choice. Based on
engineering practice, capacity and function can be expanded by expanding number of
module, so PLC has a good flexibility.
2.3.3QUALITY OF STRONG EASY OPERATION
It is very easy to edit and modify program for PLC by computer offline or online. It is
very easy to find out where the fault lie by displaying the information of fault and
function of Self Diagnosing Function, and all these make maintenance and repair for
PLC easier. It is very easy to configure PLC because of modularization,
standardization, serialization of PLC
2.3.4EASY PROGRAMMING AND MODIFICATION

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Programming in PLCs is easier in terms of coding and logic designing. In comparison
to embedded system and micro-controllers it is easier to programme a PLC and also
modification of logical design of PLCs is easier. Since it is veryuser friendly and
contains various function blocks so working with PLCs has its own advantages in
various fields.
2.3.5 LONGER LIFE
PLCs are free from problem of ageing due to their rugged construction and static
relays have longer life. Since heating effect is lesser in case of PLCs the reduction in
efficiency and performance is no more a problem either.
2.3.6 VAST APLLICATION
Application of PLCs is vast and they can be used in and of application in various
industries from power plant to manufacturing and from controlling to security they
serves many purposes in a single build that ultimately is an advantage and saves space
and complexity of system is reduced to a large extent.
All these features add up and create an ultimate system which assures a high
performance in terms of accuracy, efficiency and productivity in all the industrial and
controlling processes carried out in various fields like industries, power plants,
controlling station and other concerning areas.
2.4 ARCHITECTURE
It consists of a central processing unit (CPU) containing the system microprocessor,
memory, and input/output circuitry. The CPU controls and processes all the
operations within the PLC. It is supplied with a clock with a frequency of typically
between 1 and 8 MHz’s This frequency determines the operating speed of the PLC
and provides the timing and synchronization for all elements in the system. The
information within the PLC is carried by means of digital signals. The internal paths
along which digital signals flow are called buses. In the physical sense, a bus is just a

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number of conductors along which electrical signals can flow. It might be tracks on a
printed circuit board or wires in a ribbon cable.
Fig.: 2.2 Basic PLC architecture
The CPU uses the data bus for sending data between the constituent elements, the
address bus to send the addresses of locations for accessing stored data and the
control bus for signals relating to internal control actions. The system bus is used for
communications between the input/output ports and the input/output unit.
2.4.1 CPU
The internal structure of the CPU depends on the microprocessor concerned. In general they
have:
o An arithmetic and logic unit (ALU) which is responsible for data
manipulation and carrying out arithmetic operations of addition and
subtraction and logic operations of AND, OR, NOT and EXCLUSIVE-OR.
o Memory, termed registers, located within the microprocessor and used to
store information involved in program execution.
o A control unit which is used to control the timing of operations.

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The CPU itself has a few different operating modes.
 Programming Mode.
 Run Mode.
 Stop Mode.
 Reset Mode
BASIC INTRODUCTION ABOUT GATE WITH LADDER LOGIC
PROGRAMMING:-

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2.4.2 The buses
The buses are the paths used for communication within the PLC. The information is
transmitted in binary form, i.e. as a group of bits with a bit being a binary digit of 1 or
0, i.e. on/off states. The term word is used for the group of bits constituting some
information. Thus an 8-bit word might be the binary number 00100110. Each of the
bits is communicated simultaneously along its own parallel wire. The system has four
buses:
□ Data Bus
□ Address Bus
□ Control Bus
□ System Bus

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2.4.3 Memory
There are several memory elements in a PLC system:
□ System read-only-memory (ROM) to give permanent storage
□ Random-access memory (RAM) for the user’s program.
□ Random-access memory (RAM) for data.
□ Possibly, as a bolt-on extra module, erasable and programmable read-only-
memory (EPROM) for ROMs that can be programmed and then the
programmade permanent.
The programs and data in RAM can be changed by the user. All PLCs will have some
amount of RAM to store programs that have been developed by the user and program
data. However, to prevent the loss of programs when the power supply is switched
off, a battery is used in the
PLC to maintain the RAM contents for a period of time. After a program has been
developed in RAM it may be loaded into an EPROM memory chip, often a bolt-on
module to the PLC, and so made permanent.
2.4.4 Input/ Output Unit
The input/output unit provides the interface between the system and the outside world,
allowing for connections to be made through input/output channels to input devices
such as sensors and output devices such as motors and solenoids. It is also through the
input/output unit that programs are entered from a program panel. Every input/output
point has a unique address which can be used by the CPU.
The input/output channels provide isolation and signal conditioning functions so that
sensors and actuators can often be directly connected to them without the need for
other circuitry. Electrical isolation from the external world is usuallly by means of
optoisolators (the term optocoupler is also often used
Fig.: 2.3 Optoisolator

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2.5 SOURCING AND SINKING
The terms sourcing and sinking are used to describe the way in which d.c. devices are
connected to a PLC. With sourcing, using the conventional current flow direction as
from positive to negative, an input device receives current from the input module, i.e.
the input module is the source of the current.
If the current flows from the output module to an output load then the output module
is referred to as sourcing. With sinking, using the conventional current flow direction
as from positive to negative, an input device supplies current to the input module, i.e.
the input module is the sink for the current.
If the current flows to the output module from an output load then the output module
is referred to as sinking
Fig.: 2.4 Sinking and sourcing
2.6 WORKING OF PLC
The operation of a programmable controller is relatively simple. The input/output
(I/O) system is physically connected to the field devices that are encountered in the

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machine or that are used in the control of a process. These field devices may be
discrete or analog input/output devices, such as limit switches, pressure transducers,
push buttons, motor starters, solenoids, etc. The I/O interfaces provide the connection
between the CPU and the information providers (inputs) and controllable devices
(outputs).
During its operation, the CPU completes three processes:
□ It reads, or accepts, the input data from the field devices via the input
interfaces.
processor of the PLC to evaluate all the rungs and update the I/O image table with the
status of outputs. This scan time may be a few milliseconds for a small program or on
a fast processor, but older PLCs running very large programs could take much longer
(say, up to 100 ms) to execute the program. If the scan time were too long, the
response of the PLC to process conditions would be too slow to be useful.
As PLCs became more advanced, methods were developed to change the sequence of
ladder execution, and subroutines were implemented. This simplified programming
2.6.1 Connection of PLC
Allen Bradlly PLC
□It executes, or performs, the control
program stored in the memory system.
□It writes, or updates, the output
devices via the output interfaces.
This process of sequentially reading the inputs,
executing the
program in memory, and updating the outputs is
known as scanning.
A PLC program is generally executed repeatedly as long as the controlled system is
running. The status of physical input points is copied to an area of memory accessible
to the processor, sometimes called the "I/O Image Table". The program is then run
from its first instruction rung down to the last rung. It takes some time for the

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Input Connection of PLC
Connection cable b/w PLC and PC

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Software of PLC RSLogix 500
2.7 CLASSIFICATION OF PLC
Although PLCs have vast fields of application and are used in many processes but still

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they have to be classified in order to find out the suitability and compatibility of the
system and process which we are to follow or for the application for which we use it.
We have various parameter for classification of PLCs.
2.7.1 On Basis of I/O Modules
a) Discrete I/O Module- It provides the field connection between fielddevice
and CPU which transmits and receives discrete signals.
b) Analog I/O Module- Analog input modules are used where
continuoussignal such as temperature, pressure are to be detected.
Analog output module is used where continuous current and voltage signal
is required in output.
2.7.2 On The Basis Of Application Range
a) Micro PLCs- Upto 32 I/O.
b) Small PLCs- 32 to 128 I/O.
c) Medium PLCs- 128 to 1024 I/O.
d) Large PLCs- 512 to 4096 I/O.
e) Very Large PLCs- 1024 to 8192 I/O.
2.7.3 On The Basis Of Application
a) Safety PLCs- They are designed with some form of logic
processingredundancy and monitoring as well as input and output self
checking. As you may have guessed, these cost more, roughly 30% higher
than the standard fare and are use in high risk situations.
b) PAC or Programmable Automation Controllers- They are
essentiallythe tops of the PLC food chain. They are very powerful in terms
of processing speed, extensibility, programming and communications.
c) OEM PLCs- They are generally without a case or enclosure and
thereforesuited to fit inside a product that is mass produced, for instance a
washing
2.8 APPLICATIONS OF PLC

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PLC is a very versatile device and its application area are very broad. It can be used
as a controller as well as a security equipment and most importantly it automates all
the processes and reduces the manual labor to a large extent. Some of very highly
demanding application of PLC are-
2.8.1 Application in Security- PLCs can be used in various security processes
toavoid severe losses and avoid large or minute accidents in power stations
and
grid sub stations. They can be used in commercial security too by a little bit
of modification in programming and circuitry.
PLC based security systems are more reliable, efficient and are accurate to a
large extent (depending upon the accuracy and precision of sensors).
Although they are costlier but still they can be used for large buildings with
easy application and reduced risks.
2.8.2 Controlling Applications-PLCs are primarily used as controllers for
variousindustrial and commercial processes. The relay system in PLC is used
to control various analog and digital signals and gives controlled output
according to the programing given to it in the system.
For controlling operation sensors are used to provide input signal and PLC
cpu processes the signal accordingly so that the output can be controlled and
a regulated desired output is achieved.
2.8.3 Industrial Application-PLCs have very vast industrial application below we
have some examples-
INDUSTRY APPLICATION
Manufacturing
Industry
□ complete manufacturing system
□ silo feeding control system
Travel Industry □ Escalator operation, monitored safety control
System
□ Lift operation, monitored safety control system

21
2.9 ADVANTAGES OF PLC
2.9.1 Flexibility: One single Programmable Logic Controller can easily run
manymachines.
2.9.2 Correcting Errors: In old days, with wired relay-type panels, any
programalterations required time for rewiring of panels and devices. With
PLC control any change in circuit design or sequence is as simple as retyping
the logic. Correcting errors in PLC is extremely short and cost effective.
2.9.3 Space Efficient: Today's Programmable Logic Control memory is
gettingbigger and bigger this means that we can generate more and more
contacts, coils, timers, sequencers, counters and so on. We can have
thousands of contact timers and counters in a single PLC. Imagine what it
would be like to have so many things in one panel.
2.9.4 Low Cost: Prices of Programmable Logic Controlers vary from few hundreds
tofew thousands. This is nothing compared to the prices of the contact and
coils and timers that you would pay to match the same things.
2.9.5 Testing: A Programmable Logic Control program can be tested and evaluatedin
a lab. The program can be tested, validated and corrected saving very valuable
time.
2.9.6 Visual observation: When running a PLC program a visual operation can
beseen on the screen. Hence troubleshooting a circuit is really quick, easy and
simple.
2.9.7 Pre-Defined Function Blocks: Pre-defined function blocks provides useran
opportunity to avoid extra programming for the specific functions. In PLC we
have functions like timer, counter, add, sub, RTO are pre-defined
2.10 DISADVANTAGES OF PLC
1 It is a tedious job when replacing or bringing any changes to it.
2 Skilful work force is required to find its errors.
3 Lot of effort is put to connect the wires.
4 The holdup time is usually indefinite when any problem arises.

22
CHAPTER 3
SCADA
(SUPERVISORY CONTROL AND DATA ACQUISITION)
3.1 WHAT IS SCADA?
SCADA is an acronym for Supervisory Control and Data Acquisition, which is a computer
system for gathering and analyzing real-time data. Such systems were first used in the 1960s. the
SCADA industry was essentially born out of a need for a user-friendly front-end to a control
system containing PLCs(programmable logic controllers). SCADA networks enable remote
monitoring and control of an amazing variety of industrial devices, such as water and gas pumps,
track switches, and traffic signals.
One of the key processes of SCADA is the ability to monitor an entire system in real time. This
is facilitated by the data acquisitions including meter reading and checking statuses of sensors
that are communicated at standard intervals depending on the system.
Fig.: 3.1 Control panel of SCADA
3.2 FIELDS WHERE SCADA CAN BE USED
SCADA can be used to manage many kinds of equipment. Typically, SCADA systems are used
to automate complex industrial process where human control is impractical. Around the world,
SCADA system control are used in the following industries:
3.2.1 Manufacturing: SCADAsystems manage parts inventories for JIT manufacturing.
3.2.2 Buildings, facilities and environments: facility managers use SCADA to control
HVAC.

23
3.2.3 Electrical power generation, transmission and distribution: electric utilities are
SCADA systems to detect current flow and line voltage, to monitor the operation of
circuit breakers.
3.2.4 Water and sewage: state and municipal water utilities use SCADA to monitor and
regulate water flow, reservoir levels, and pipe pressure.
3.2.5 Mass transit: transit authorities use SCADA to regulate electricity to subways, trams
and trolley buses; to automate traffic signals for rail systems.
3.2.6 Traffic signals: SCADA regulates traffic lights, controls traffic flow and detects out-
of-order signals.
3.3 HOW DOES SCADA WORK?
A SCADA network consists of one of more Master Terminal Units (MTUs), which are utilized
by operators to monitor and control a large number of Remote Terminal Units (RTUs). The
MTU is often a computing platform, like a PC, which runs SCADA software. The RTUs are
generally small dedicated devices that are hardened for outdoor use and industrial environments.
Fig.: 3.2 Working of SCADA
As we saw earlier, there are several parts of a working SCADA system A SCADA system
usually includes signal hardware , controllers, networks, user interface(HMI), communications
equipment and software.

24
3.4 WHY SCADA?
SCADA systems are an extremely advantageous way to run and monitor processes. They are
great for small applications, such as climate control, but they can be effectively used in large
applications such as monitoring and controlling a nuclear power plant or mass transit system.
SCADA can come in open and non-proprietary protocols. Smaller systems are extremely
affordable and can either be purchased as a complete system or can be mixed and matched with
specific components. Large systems can also be created with off-the-shelf components. SCADA
system software can also be easily configured for almost any application, removing the need for
custom software development.
SCADA is acronym that denotes Supervisory Control and Data Acquisition. SCADA is a control
system with applications in managing large-scale, automated industries operations. Factories and
plants, water supply systems, nuclear and conventional power generator systems etc are a few
examples. The SCADA systems, nuclear and conventional power generator etc.
3.5 ARCHITECTURE OF SCADA-
Fig.: 3.3 Architecture of SCADA
3.5.1 First generation: “Monolithic”-in the first generation, computing was done
by mainframe computers. Networking did not exist at the time SCADA was

25
developed. Thus SCADA systems were independent systems with no connectivity
to other systems. Wide Area Networks were later designed by RTU vendors to
communicate with the RTU. The communication protocols used were often
proprietary at that time. The first-generation SCADA system was redundant since
a back-up mainframe system was connected at the bus level and was used in the
event of failure of primary mainframe system.
3.5.2 Second generation: “Distributed”-the processing was distributed across
multiple stations which were connected through a LAN and they shared
information in real time. Each station was responsible for a particular task thus
making the size and cost of each station less than the one used in First Generation.
The network protocols used were still mostly proprietary, which led to significant
security problems for any SCADA system that received attention from a hacker.
3.5.3 Third generation: “Networked”- Due to the usage of standard protocols
and the fact that many networked SCADA systems are accessible from the
internet; the systems are potentially vulnerable to remote cyber-attacks. On the
other hand, the usage of standard protocols and security techniques means that
standard security improvements are applicable to the SCADA systems, assuming
timely maintenance and updates
3.6 COMPONENTS OF SCADA-
3.6.1 A human- machine interface or HMI- HMI is the apparatus which
presents process data to human-machine interface or HMI is the apparatus which
presents process data to a human operator, and through which the human operator
controls the process. An HMI is usually linked to the SCADA system’s databases
and software programs, to provide trending, diagnostic data, and management
information such as scheduled maintenance procedures, logistics information,
detailed schematics for a particular sensor or machine and expert-system
troubleshooting guides. The HMI system usually presents the information to the
operating graphically, in the form of a mimic diagram. This means that the
operator can see a schematic representation of the plant being controlled.

26
3.6.2 System concepts- A supervisory (computer) system, gathering (acquiring) data
on the process and sending commands (control) to the process. The term SCADA
usually refers to centralized systems which monitor and control entire sites, or
complexes of systems spread out over large areas. Most control actions are
performed automatically by RTUs or by PLCs. Host control functions are usually
restricted to basic overriding or supervisory level intervention.
3.6.3 Remote terminal units (RTUs) - RTU used to connecting sensors in the
process, converting sensor signals to digital data and sending digital data to the
supervisory system. The RTU connects to physical equipment. Typically, an RTU
converts the electrical signals from the equipment to digital values such as the
open/closed status from a switch or a valve, or measurements such as pressure,
flow, voltage or current. By converting and schematic these electrical signals out
to equipment the RTU can control equipment, such as opening or closing a switch
or a valve, or setting the speed of a pump. It can also the flow of a liquid.
3.6.4 Programmable logic controller (PLCs) - PLC is a solid state device or
mini industrial computer that performs discrete or sequential logics in a factory
environment. It was originally developed to replace mechanical relay, timers, and
counters. PLCs are successfully used to execute complicated control operations. Its
purpose to monitor crucial parameters & adjust process operation accordingly. It is
a digital computer used for automation of electromechanical processes, such as
control of machinery on factory assembly lines, amusement rides, or light fixtures.
PLCs are used in many industries and machines.
3.6.5 Supervisory station- communication infrastructure connects the supervisory
system to the remote terminal units. The term supervisory station refers to the
servers and software responsible for communicating with the field equipment
(RTUS, PLCs, etc.), and then to the HMI software running on workshops in the
control room, or elsewhere. In smaller SCADA systems, the master station may be
composed of a single PC. In larger SCADA systems, the master station may
include multiple servers the multiple servers will often be configured in a dual-

27
redundant or hot-standby formation providing continuous control and monitoring
in the event of a server failure.
3.7 FEATURES & THEIR FUNCTIONALITY-
3.7.1 Dynamic process Graphic – it should resemble the process mimic. SCADA
should have good library of symbols so that develop the mimic as per required.
When operator sees the screen he should know what’s going in plant. By this
feature, graphic develop which can resemble the plant. The graphics can include
reactors, valve, pumps, agitators, conveyors as well as other equipment and
machinery used in the plant. The status of the equipment running / stopped can be
shown using different colors / animation.
Typically the SCADA software will have many ready to use symbols for proper
representation which can be used in any type of industry.
3.7.2 Alarm summary & Alarm history – A SCADA system must be able to
detect, display and log alarms and events. When there are problems the SCADA
system must notify the operators to take corrective a action. Alarms and event must
be recorded so that engineers and programmers can review the alarm to determine
what caused the alarm and prevent them happening again.

28
More complicated expressions can be developed by creating derived parameters on
which status or limit checking is then performed. The alarms are logically handled
centrally, i.e. the information only exists in one place and all users see the same
status, and multiple alarm priority levels are supported.
3.7.3 Real time trend & Historical time trend – The trends play very important
role in the process operation. If batch fails or the plant trips then historical trend
data used and do the analysis. Better look of the representing parameters through
the trends in graphical form the trend plots the value with reference to the time.
Real-time data will plot the real –time value for fixed period of time while
historical data will have historical data stored value which can be viewed on
demand. Depending upon the storing capacity of the hard-disk one can specify the
no of days the data can be stored.
3.7.4 Security (Application Security) – Allocated certain facilities or features to
the operator, process people, engineering dept. & maintenance dept. for example
operators should only operate the system, not be able change the application. The

29
engineers should access to changing the application. The engineers should access
for securing the application by avoiding unauthorized access.
Depending upon the access level given the operator/ engineers allowed to do the
task.in most of the cases, the operators are allowed only to operate the plant while
maintenance engineers can do the application modifications. The security can be
given for individual as well as for groups.
3.7.5 Database connectivity – in manufacturing units go for Enterprise Resource
Planning (ERP) or management Information System (MIR). One can produce
reports using SQL type queries to the archive, RTDB or logs. Although it is
sometimes possible to connect embed EXCEL charts in the report. Facilities exist
to be automatically generated, print and archive reports. It is important to download
the real-time information to the MIS.

30
In this case the database connectivity is must. Much SCADA software doesn’t have
their own database. Hence for storage and reporting they use third party database
like MS Access or SQL.
3.7.6 Device connectivity – There are hundreds of automation hardware
manufacturer like Modicon, Seimens, Allen Bradely, Yokogawa, ABB. There are
own communication protocol. SCADA s/w should have connectivity to the
different hardware used in automation. It should not happen that for Modicon buy
one software & for seimens another one.
The software like Aspic or Wonderware has connectivity to almost all hardware
used in Automation. Every control hardware has its own communication protocol
for communicating with different hardware / software. Some of the leading
communication protocol include Modbus, Profibus, Ethernet, DH +, DH 485,
Devicenet, Control net.
3.7.7 Scripts – the majority of the products allow actions to be automatically triggered
by events. Scripting languages provided by the SCADA products allow these
actions to be defined. The concepts of receipts is supported, whereby a particular
system configuration can be saved a file and then re-loaded at a later date.
Sequencing is also supported, it is possible to execute a more complex sequence of
actions on one or more devices. Sequences may also react to external events.
Scripts is a way of writing logic in SCADA software. Every SCADA software has
its own instructions and way of writing program.
3.7.8 Recipe management – it is an additional feature. Most of the plants are
manufacturing multi products. When Different product to manufacturing, then
recipe of that particular get locked. The same plant for manufacturing different

31
product range. For example an oil blending plant can manufacture power oil,
transformer oil, and automobile oil.
It is the facility used for maintains various recipes of different products and
implement it on the process. The recipe can be stored in a single server and it can
be fetched by any client server from any area to run the process.
3.7.9 Networking – in an application, we have to use more than one SCADA software
operator stations. This can be achieved by taking the SCADA node on network.
Ethernet TCP/IP is commonly used for networking.
3.7.10 Data Acquisition – SCADA must be able to read data from PLCs and other
hardware and then to analyze and graphically present that data to the user. SCADA
systems must be able to read and write multiple sources of data.
3.7.11 Operator Interface– A SCADA system collects all of the information about a
process. The SCADA systems then need to display this data to the operator so that
they can comprehend what is going on with process
3.8 Developers of SCADA
1. Wonderware : Intouch
2. Allen Bradly : RS view
3. Siemens : winCC
4. Intelution : iFix
5. KPIT : ASTRA
6. Modicon : Vijeocitect

32
3.9 Working with Intouch SCADA Script:-

33
3.10 Component of SCADA (SENSOR) :-
3.10.1 What are sensors?
A sensor is a device that detects and responds to some type of input from the physical
environment. The specific input could be light, heat, motion, moisture, pressure, or any
one of a great number of other environmental phenomena. The output is generally a
signal that is converted to human-readable display at the sensor location or transmitted
electronically over a network for reading or further processing.
Here are a few examples of the many different types of sensors:
In a mercury-based glass thermometer, the input is temperature. The liquid contained
expands and contracts in response, causing the level to be higher or lower on the marked
gauge, which is human-readable.
An oxygen sensor in a car's emission control system detects the gasoline/oxygen ratio,
usually through a chemical reaction that generates a voltage. A computer in the engine
reads the voltage and, if the mixture is not optimal, readjusts the balance.
Motion sensors in various systems including home security lights, automatic doors and
bathroom fixtures typically send out some type of energy, such as microwaves, ultrasonic
waves or light beams and detect when the flow of energy is interrupted by something
entering its path.
Classification based on property is as given below:
· Temperature - Thermistors, thermocouples, RTD’s, IC and many more.
· Pressure - Fibre optic, vacuum, elastic liquid based manometers, LVDT, electronic.
· Flow - Electromagnetic, differential pressure, positional displacement, thermal
mass, etc.
· Level Sensors - Differential pressure, ultrasonic radio frequency, radar, thermal
displacement, etc.
· Proximity and displacement - LVDT, photoelectric, capacitive, magnetic,
ultrasonic.
· Biosensors - Resonant mirror, electrochemical, surface Plasmon resonance, Light
addressable potentio-metric.
· Image - Charge coupled devices, CMOS
· Gas and chemical - Semiconductor, Infrared, Conductance, Electrochemical.
· Acceleration - Gyroscopes, Accelerometers.
· Others - Moisture, humidity sensor, Speed sensor, mass, Tilt sensor, force,
viscosity.

34
3.11 APPLICATIONS OF SCADA-
Unlike in plant process control systems, SCADA systems typically include a remote
telecommunication link. Real-time measurements and controls at remote stations are transferred
to a CPU through the communication link. Large systems can monitor and control 10-2000
remote sites, with each site containing as many as 2000 I/O points. By small industrial
companies the technology was deemed unobtainable because of high association with those
systems could not be fully used because of their massive I/O capacities. Application size can be
20k I/O to 450k I/O under development. A typical SCADA application requires several low cost
distributed RTUs. Controlled by a central station/master. Applications in plant process control
system-
3.11.1 Building maintenance – It provides a quick and easy method for creating
graphical views of your building monitoring and control systems. Use a common
Web-enabled user interface to integrate facility functions such as HVAC, lighting,
energy, security, fire and elevator giving maintenance personnel and other

35
operators an easy way to display, monitor and control critical key operating
parameters in multiple facilities from a single location.
3.11.2 Energy – The energy industry is one of today’s most dynamic business
environment with decisions being driven by increased regulation, growing demand
and escalating costs. Used in electrical utility control centers to present a graphical
view of the power system and the capability to analyze past and current events as
well as to predict potential future issues.
3.11.3 Manufacturing– It makes easy to monitor and control multiple shop floor
processes from a single location and have immediate visibility to data trends,
making it easy to anticipate potential problems. The manufacturing assembly,
engine testing, robotic welding, paint shop and material handling can benefit.
3.11.4 Water & Waste Water– the following water and wastewater includes that
can benefit from SCADA solutions sanitation systems, water utilities,
municipalities, distribution, filtration, desalination, remediation, etc. It provides
water and wastewater processing organizations with powerful real-time data
visualization tools to display, monitor and control all areas of the process.
3.11.5 Healthcare– The following health care industry segments that can benefit:
hospitals and other health care facilities, drug and pharmaceutical, water
purification systems, packaging, medical equipment manufacturing, etc. offers a
data visualization solutions that saves time and efficiently supports the overall
management of today’s health care and pharmaceutical industry.
3.11.6 Petrochemical– The oil, gas and petrochemical companies need to be able to
easily manage their daily operations while adhering to regulatory requirements. It
enables monitoring and control of data as well heads, pumping stations and
cooling towers, etc. – between geographically isolated locations from a single
location. The following oil, gas & petrochemical industries that can benefits from
mobiform data visualization solutions: refineries, logistics, production,
manufacturers, suppliers etc.
3.11.7 Digital Signage solutions– it is the perfect solution for digital signage
application in areas such as corporate communications, education, tourism, retail,

36
financial services, restaurant, conferences, etc. It is a powerful software design
solution for your digital signage display needs. Using status, companies can
display meaningful real-time information such as sales or manufacturing figures
or, using the built-in Scheduler, cycle a series of messages generated by the
designer for corporate visitors, internal or other employee messages.
3.12 ADVANTAGES OF SCADA-
 The computer can record and store a very large amount of data
 The data can be displayed in any way the user requires
 Thousands of sensors over a wide area can be connected to the system
 The operator can incorporate real data simulations into the system
 Many types of data can be collected from the RTUs
 The data can be viewed from anywhere not just on site
3.13 DISADVANTAGES OF SCADA-
 The system is more complicated than the sensor to panel type.
 Different operating skills are required, such as system analysis and programmer.
 With thousands of sensors there is still a lot of wire to deal with.
 The operator can see only as far as the PLC.
 IP performance over head.
 Web enabled SCADA hosts users to remotely monitor.
 Control remote sites via web browser
 Security concerns.

37
CHAPTER 4
CONCLUSION
This report has discussed the role that programmable logic controllers have in the efficiebt
design and control of mechanical processes. Also discussed was the understanding SCADA and
the programming involved with it. Finally the report has discussed relat logic and the evolution
that ladder logic made from it.
1. Programmable logic history: This section discussed the history and advancement of
controls technology with a comparison of programmable logic controllers and hard-wired
relay.
2. PLC component: This section defined what programmable logic is and described all
hardware associated with it.
3. PLC Programming: This section covered various technique of PLC programming.
4. SCADA: This section contain basic introduction of SCADA system.
Around the world, PLC – SCADA systems control

38
1. Elecric power generation, transmission and distribution
2. Manufacturing industries
3. Mass transit & water management systems
4. Traffic signals
5. Cement and petrochemical industries
6. Automobile industries
New technology directions
Industrial automation will generate explosive growth with technology related to new
inflection points: nanotechnology and nanoscale assembly systems; MEMS and nanotech
sensors (tiny, low-power, low-cost sensors) which can measure everything and anything; and
the pervasive Internet, machine to machine (M2M) networking.
Real-time systems will give way to complex adaptive systems and multi-processing. The
future belongs to nanotech, wireless everything, and complex adaptive systems.
Major new software applications will be in wireless sensors and distributed peer-to-peer
networks – tiny operating systems in wireless sensor nodes, and the software that allows
nodes to communicate with each other as a larger complex adaptive system. That is the wave
of the future.

Plc & scada report 6

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