Batch 25(a)
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This document provides an overview of RS232 and E1 communication standards. It discusses the classification of communication, RS232 data format including baud rate, transfer modes, cabling and pinouts. It then describes the E1 frame structure including timeslots and frame alignment. The document includes block diagrams of an RS232 to E1 converter.
Batch 25(a)
- 1. Faculty Guide :Ms.J.Prathiba Project Guide :Mr.M.Naresh By, BALA RAJESWARI ELCHURI Batch-25
- 2. CONTENTSCONTENTS Classification of communication Transfer modes RS232 Data Format RS232 Cabling DB9 & RS232 Connection Pins RS232-E1 Converter RS232-E1 Converter Block Diagram E-Carrier E1-Frame Structure Timeslots Frame Alignment CRC Technique 2 2
- 3. Classification of communicationClassification of communication Wired Communications Parallel Serial Wireless Communications Bluetooth ZigBee 3
- 5. Serial CommunicationsSerial Communications 5 5Baud Rate – A measure of how fast serial data is moving between devices per second. 2 common levels are 19, 0 BPS and 9,600 BPS
- 6. Transfer modesTransfer modes Synchronous: •Clock signal wire is used by both receiver and sender to sample data Asynchronous: •No clock signal in common •Data must be over-sampled •Needs only three wires (one data for each direction, and ground) 6 Preamble Message Postamble10101010
- 7. RS 485RS 485 RS-485 allows multiple devices (up to 32) to communicate at half-duplex on a single pair of wires, plus a ground wire, at distances up to 1200 meters (4000 feet). This standard specifies differential signalling rather than single ended ground. A logic 1 is a level > than -200mV and a logic 0 is a level > than +200mV. Nominal characteristic impedance is 100 or 200Ώ. To transmit a logic 1, line B is high and line A is low. To transmit a logic 0, line B is low and line A is high. The advantage of this arrangement is that signals can be transmitted faster and over greater distances than is possible with a single wire.
- 8. RS 485RS 485 Two wires are required for each signal. Full Duplex System: Sending and Receiving Data over 4 Wires Half Duplex System: Sending and Receiving Data over 2 Wires • In many RS485 systems there are times when no unit is driving the RS485 lines. They can then go to any voltage and may produce serial errors. To avoid this it is often necessary to fit resistors which pull one line high and the other line low putting the line into the passive state.
- 9. RS232 InterfaceRS232 Interface It is an Interface between Data Terminal Equipment and Data Communications Equipment allowing Serial Binary Data Interchange. RS- Recommended Standard DTE ---- DCE DTR ---> DSR <--- RTS---> CTS<--- DCD<--- DCE DCE DTE DTE RS-232 RS-232Long distance
- 10. RS232 Voltages Data FormatRS232 Voltages Data Format Start Bit, Stop bit , Data bits, Parity Bit (odd, even, none)
- 11. RS 232RS 232 11 Slew Rate – Speed we can go from -25 V to 25 V, limits baud
- 12. RS 232RS 232 • Logic 0 is called “space”. • Logic 1 is called “mark”.
- 13. RS 232RS 232 • The voltage sent by using the RS-232 standard are sent with reference to a ‘common ground or 0-V point’-called Single-ended. 13 RS-232 Driver Circuit RS-232 Receiver Circuit Data Handshake Handshake Common Ground
- 14. Pin-out Diagram for making RS-232 Interfaces FunctionPin-out Diagram for making RS-232 Interfaces Function DTE Connector Transmit Data Clear to Send Request to Send Receive Data Signal Ground Protective Ground
- 15. CablingCabling 15 Electrical Interfaces RS232 DCE (Data Communication Equip) – modem(Both TX & Rx) DTE (Data Termination Equipment) - terminals, system, etc. (basically everything except a modem) DCE is designed to plug straight into a DTE. To connect a DTE to a DTE, need a null modem, our devices are DTE (termination) devices
- 16. NULL Modem AdapterNULL Modem Adapter Using only TD, RD, and SG No need for flow control (May miss characters if sent too fast) Both ends ready to send/receive at any time 16 DTE Null modem DTE This adapter does the swapping for you. DTE Modem = DCE modem DTE
- 17. CablesCables 17 Most Peripherals are DTE devices so need a Null Modem RXD TXD GND RXD TXD GND RXD TXD GND RTS CTS DSR DTR DCD RXD TXD GND RTS CTS DSR DTR DCD Full Null Modem Cable:Minimal Null Modem Cable:
- 18. 18 EIA-232F For a DB9 Connector 18
- 19. Pin-outs -DB9 to RS232Pin-outs -DB9 to RS232 DB9 Pin Number RS232 Name Direction 1 DCD In 2 RXD In 3 TXD Out 4 DTR Out 5 SG Ground 6 DSR In 7 RTS Out 8 CTS In 9 RI* In Standard DB9 PC serial port:
- 20. RS232 to E1 ConverterRS232 to E1 Converter RS232 INTERFACE SPECIFICATIONS: • Rs232 interface rate : 9600 Kbps, 19200 Kbps, 38400 Kbps, 56000 Kbps, 115200 Kbps • Even or Odd parity selection. • RS232 port protection : 600W surge protection, 15KV static protection • RS232 port connector DB25 female • LED INDICATIONS : PWR, E1 Sync, AIS, TD, RD, TST. • BUILT-IN POWER : DUAL MODE AC/DC, 230VAC +/- 10% & –48VDC +/-10% • TEMPERATURE : -5 To 50°C • HUMIDITY : Upto 95% non condensing at 35°C
- 21. RS232 to E1 ConverterRS232 to E1 Converter 21 • RS232 to E1(G.703) interface converter will converts RS232 Asynchronous data into 2.048 Mbps E1 data or Nx 64 Kbps E1 data. • It supports both framed and Unframed operations over E1 channel. E1 INTERFACE SPECIFICATIONS: • Line Rate : 2048 Kbps • Line Code : HDB3 • Interface : E1 Interface as per ITU-T G.703, G.704 • Impedance : 120 Ohms(Balanced), Optional : 75 Ohms(Unbalanced) • Connector : RJ45 for Balanced and BNC for Unbalanced • Clock Mode : Internal clock or G.703 Recovered clock • Framed and Unframed Operation • User selectable CRC-4 Generation and Detection
- 22. E1 Frame structureE1 Frame structure •An E1 link operates over two separate sets of wires, usually – Unshielded twisted pair (balanced cable) – using coaxial (unbalanced cable). •Line Data Rate - 2.048Mbps •Each frame is for 125 uS •Divided into 32 Timeslots •Each Time slot Consists of 8 Bits.
- 24. Time Slot 0Time Slot 0 The time slot 0 is devoted to transmission management and time slot 16 for signaling Consists of: Frame Alignment Signal CRC-4 Multiframe Alignment signal Alarm Bit
- 26. CRC-4CRC-4
- 27. Time Slot 16Time Slot 16
- 28. The E-carrier standards (ITU - Recommendation G.703,G.704,7043) form part of the Plesiochronous Digital Hierarchy (PDH) where groups of E1 circuits may be bundled onto higher capacity links between telephone exchanges. E1 circuits have been used widely in telephony (ISDN, GSM), datacom (leased lined, Frame Relay) and synchronization of SDH and Mobile Network E-carrier
- 29. 232-E1 Conversion Block Diagram232-E1 Conversion Block Diagram UART Commu- nication 232 Levels Conversion E1 MODEM 232 Levels Conversion UART Commu- nication E1 MODEM E1 LINE TxTx Rx Terminal Terminal
- 30. Thank you
Editor's Notes
- #5: Printer port LPT1 is an example of this.
- #6: Asynchronous uses a start bit and a timer and measures the time to the center of each pulse. The Parity bit is used to check and make sure the data is correct and the stop bit is use to tell you the end of byte. You also have a Master and Slaves
- #12: DTE Data Terminal Equipment DCE Data Communication Equipment 15 meters or less, baud rate of 19, 0 or less