This document provides a summary of the author's summer training internship at the Divisional Railway Manager Office in Ajmer. It discusses the railway communication systems used including the automatic electronic exchange, C-DOT electronic exchange, important exchange cards, call processing, and interactive voice response, passenger reservation, and optical fiber communication systems. The training covered various technical aspects of the railway working systems including RAILNET, microwave communication, and signaling departments.

1. 1
A
PRACTICAL TRAINING REPORT
ON
SUMMER TRAINNING
TAKEN
AT
DIVISIONAL
RAILWAY MANAGER OFFICE
AJMER
Submitted in partial fulfillment
For the award of the degree of
BACHELOR OF TECHNOLOGY
(Rajasthan Technical University, Kota)
IN
ELECTRONICS & COMMUNICATION ENGINEERING
SESSION (2015-2019)
SUBMITTED TO: SUBMITTED BY:
Seminar Coordinator LOKESH PARIHAR
ECE DEPARTMENT 15EEAEC048
ECE, VII SEM

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DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGG.
GOVERNMENT ENGINEERING COLLEGE AJMER
NH-8, BARLIYA, AJMER-305025
TABLE OF CONTENTS
SNo. TITLE PAGE No.
1. Introduction to railway 1
2. Railway zone headquarters 1
3. Automatic electronic exchange 2
4. C Dot electronic exchange 2
5. Functions of important cards 3
5.1 PSU cards 3
5.2 Subscriber line card 4
5.3 Tone generator & diagnostic card 4
5.4 Control card 5
5.4.1 Rack control card 5
5.4.2 TIC card 6
6. Call processing 6
6.1 Call processing 6
6.2 Dialing 7
6.3 Response of called party & conversion 8
6.4 Disconnection 8
7. Maintenance panel 8
8. Interactive voice response system 9
8.1 Hardware 9
8.1.1 Data entry terminal 10
8.1.2 Modem 10
8.1.3 IVRS terminal 10
8.2 Software 10
8.2.1 COPETs software 11
8.2.2 Communication software 12
8.2.3 OLTRIS software 12
9. Passengers reservation system 13
10. CSTM main frame computer 15
11. RAILNET 15
11.1 Introduction 15
11.2 Organization 15
11.3 Rail-Net comprises 15
11.4 Tools 15

3. 3
11.5 Objective 16
11.6 General arrangement 16
11.7 Hardware component 16
11.8 Software component 16
12. Network components 16
12.1 Server 16
12.2 Router 18
12.3 Switch 19
12.4 Firewall 19
12.5 Hub 20
12.6 Network Interface Card 20
13. Medium of communication 20
13.1 Over head lines 21
13.2 Optical fiber communication 23
14. Block diagram of optical fiber communication 24
15. Dual Tone multi frequency 25
16. Signaling department 25
16.1 Introduction 26
16.2 Data Logging System 28
16.3 Front End Processor 28
16.4 Computer &Control Room 28
16.5 Modem 28
16.6 Communication 30
16.7 Data Logger 32
17. Bibliography 33

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TABLES & FIGURES
SNo. Contents PG.No.
1. TABLES
1.1 Table 5.1- Dial Tones with Specific Frequencies 6
2. FIGURES
2.1 Fig 8.1: IV Response System 9
2.2 Fig 9.1: Concert Network Topology 15
2.3 Fig 12.1: Network Components 18
2.4 Fig 12.2: Switch 19
2.5 Fig 12.3: Hub 20
2.6 Fig 13.1: Optical Fiber 30
2.7 Fig 13.2: Wave Propagation In OFC 32
2.8 Fig 14.1: Communication Through OFC 32

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AKNOWLEDGEMENT
This is opportunity to express my heartfelt words for the people who were part of this training
in numerous ways, people who gave me unending support right from beginning of the
training.
I am grateful to training incharge Mr. Harish Sharma for giving guidelines to make the
project successful.
I want to give sincere thanks to the principal, Dr. Ranjan Maheshwari for his valuable
support.
I extend my thanks to Dr. U. S. Modani Head of the Department for his cooperation and
guidance.
Yours Sincerely,
LOKESH PARIHAR
(Student Signature)

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ABSTRACT
Indian Railways a government firm established in year 1853 and steamed off its first train
routed from Mumbai to Thane a distance of 34 Km. About 30% of route kilometer and 41%
of running track kilometer and 43% of track kilometer is electrified. In total according to
2013 survey we have 17 Railway Zones in India. In order to maintain such a wide network,
we require a perfect engineering of communication system so that to achieve synchronization
with rest of other zones. A good communication between different zones can be achieved
with the help of various departments which are included in this training report. The report is
based on the working of particularly North Western Railway, Ajmer Division. The main part
of railway communication system includes optical fiber communication , optical fibers are
small thin strands of glass covered with a coating of material having low refractive index as
compared to glass and a protective layer of cladding is used. OFC is very advantageous
technique in comparison to conventional copper cables. This report is a brief description of
summer training program focusing on technical aspects of Railways Working System
Following courses were studied under this training period:-
1. RAILNET
2. Microwave Communication
3. Digital Electronic Exchange
4. Freight Operation & Information System
5. Control communication
6. Interactive Voice response System
7. Passenger Reservation System
8. Unreserved Ticketing System
9. Passenger Information System
10. Optical fiber Communication

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1. INTRODUCTION TO RAILWAY
Indian Railways………the golden Era
16th April, 1853………The Beginning
The first railway on Indian sub-continent ran over a stretch of 21 miles from Bombay to
Thane.
INDIAN RAILWAY whenever this name strikes in my mind, I visualize a long train, big
office, large number of workers, modern technology etc., in fact Indian Railway is the biggest
employer in the world, largest single undertaking in the country and second biggest
electrified system in the world after Russia. The Indian railway has been divided in to sixteen
zones, which are following--:
2. RAILWAY ZONES HEADQUATERS
1. Central Railway Mumbai
2. Eastern Railway Fairy Place, Kolkata
3. Northern Railway Baroda house, Delhi
4. North East Railway Gorakhpur
5. North East Frontier Railway Malegaon(Guwahati)
6. Southern Railway Chennai
7. South central Railway Secundrabad
8. South Eastern Railway Garden Reach, Kolkata
9. Western Railway Church Gate, Mumbai
10.East Coast Railway Bhuvneshwar
11.North Central Railway Allahabad
12.South Western Railway Hubli
13.West Central Railway Jabalpur
14.East Central Railway Hajipur
15.North West Railway Jaipur
16. South East Central Railway Bilaspur

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3. AUTOMATIC ELECTRONIC EXCHANGE
Railway has its own communication system including microwave stations and automatic
electronic exchange.
Ajmer Division exchange consists of three main exchanges:-
1. First is having a capacity of 128 lines. It is based on C-DOT technology which is an
Indian technology and it is a product of RTPL ( Raj. Telematics Pvt. Ltd.).
2. Second one has the capacity of 1200 lines and is based on OKI technology. It is a
collaboration product of TATA Telecom and Compton Greaves.
3. Third one has the capacity of 60 lines. It is a MKT (Multi Key telephone exchange). It
is a product from Nitsuhu-Enkay. It provides ISDN (Integrated Switching Digital
network) facility to railway.
These three exchanges cater all the requirements of Ajmer proper.
4. C-DOT ELECTRONIC EXCHANGE:-
It is an Indigenous SPC exchange developed by “Center for development of telemetric”, C-
DOT. C-DOT is developed on one microprocessor IC i.e. 65C02.128 ports C-DOT exchange
are commonly used in railways. The 128 port exchange has a limitation i.e. the maximum
subscribers accommodation are 96 with 8 junction lines and can be extended up to 24 with
reduction of subscriber lines.
They are:
● 96 subscriber lines + 8 trunk (junction) lines.
● 88 subscriber lines + 16 trunk (junction) lines.
FEATURE OF RAX 128 EXCHANGE:-
1) 128 Terminations can be accommodated in single frame
2) Fully digital exchange
3) Stored program controlled
4) Non blocking exchange
5) Modulator expansion

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6) Less installation time
7) Flexible system dimensioning
8) Low power consumption
9) Single fault can effect not more than 8 terminations expect processors portion
10) Can work up to 45˚c, So no air condition is required
11) Man-machine communication by maintenance console
12) Subscriber loop resistance is 1900 Ω for normal subscriber
13) Impulse make break ratio can be expected up to 50-80%
14) It is design for wide range of temperature, humidity and other environment condition
15) Provision for air filter to prevent the exchange from dust
16) It is rigid so rough transport can be with stand
17) It requires little maintenance and has facility for central monitoring and testing
18) The technology is based on indigenous hardware and software, assuring full local
support for future updating
19) Cost of equipment is very low
20) Technology is quit latest and compatible with other international product.
5. FUNCTION OF IMPORTANT CARDS:-
PSU CARD:-It is switch mode power supply card worked on -48±48 DC
Feature:-
(A) It feeds -48 V dc to subscriber line card and senses the flow of current in line
● If current is more than 10 mA and up to 35 mA max, it is treated that subscriber has
lifted the handset.
● If less than 10 mA the card treats as on the hook condition
(B) PSU generates other supplies for various cards through dc to dc converter.
● +5V regulated (8Amp)
● 12V regulated (1Amp)
● -5V (0.1Amp) regulated
● -9V (0.3Amp) regulated
(C) It also generates 75 volt AC for ring current purpose. 12 volt regulated is used for
SLC card relay operation i.e. for test relay & ring relay. Two PSU cards share the
exchange load equally, but in case of fault the other PSU cattier the full load.

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SUBSCRIBER LINE CARD (SLC CARD):-
There are 10 SLC cards. Each card contains 10 lines. They are not duplicated cards. In
addition of these 10 cards, there are 3 trunk cards, out of which 2 trunk cards can be replaced
to 2 SLC cards. One trunk card can not be replaced because it is an E&M card of 4 wire
system.
Features:-
It performs the functions collectively termed as BORSCHT means:
B- Battery feed
O- Over voltage protection
R- Ringing
S- Supervision
C- Coding
H- Hybrid conversion
T- Testing
(1) It acts as a terminal card for interfacing subscriber & exchange
(2) Each card has 8 identical circuits catering 8 subscribers
(3) Enable the voice of the subscriber to reach a port with in exchange for onward
transmission to calling and called party
(4) It has provision to operate for any of the 2 input signals from copy ‘0’ to copy ‘1’.
(5) It communicates with TIC/SN card for voice data.
(6) SLC communicates with SP for signaling data.
Each subscriber circuit has 2 relays. One is testing relay which isolates subscriber line from
exchange and now line can be checked. The other relay is ring feed relay; it feeds the
ringing current to the called party.
TONE GENERATOR & DIAGNOSTIC CARD (TGD):-
These cards generate 8 different tones to indicate different status of the subscriber line. It
also has diagnostic circuit. TGD can diagnose the function of the card and give an error-
reporting signal to TIC card. When it is required to feed a tone to subscriber, the time slot
of particular tone is switched to time slot of the subscriber. Hence subscriber hears the tone.

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The tones are:
Tone Frequency On-Off period Time-
out
Dial Tone 400 Hz + 25
Hz
Continuous 10 sec
Busy Tone 400 Hz .75 sec on; .75 sec
off
10 sec
Ring Back
Tone
400 Hz + 25
Hz
.4 sec on; .2 sec
off
60 sec
NU Tone 400 Hz 2.8 sec on; .2 sec
off
60 sec
Table 5.1- Dial Tones with Specific Frequencies
CONTROL CARDS:-
These are 3 cards, which form a control network:-
● RCP-RAX Control processor
● TIC- Terminal Interface Collector
● SP- Signal processor
All the control cards are duplicated. One copy is active and other is passive. In case of fault,
the system switches over to passive copy automatically making passive copy active. RCP,
TIC and SP form a group and at a time one group is active and other is passive. Any single
change over is registered on the maintenance panel.
RACKS CONTROL CARD:-
Features:-
● Main controller (Master)
● Microprocessor 65C02 (C-MOS up)
● Perform call processing, administrative & maintenance functions
● Exchange database

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● Man-machine interaction through the maintenance panel (MP)
● Communication link with the TIC, MP and duplicate RCP
● Extensive system diagnostic
TIC Card/ SN (Switching Network):-
Terminal interface card and switching network is a completely non blocking network and
allows for higher traffic handling capacity. Four PCM-32 links form the terminal group and
undergo to ‘TDM’ to generate PCM 128 channel link.
Features:-
1) TIC / SN card is an 18 time slot switch. Switching (PCM) digital voice information
b/w 128 ports to enable he subscriber to converse with each other and feed different
tones.
2) The microprocessor is of 8 bit i.e. 65C02 type.
3) TIC work under the instruction of RCP.
4) TIC controls SP (Signal Processor) & SN (Signal network).
5) TIC also gathers information from SP and send to RCP.
6) The card has 32 KB EPROM & 16KB RAM for stretch pad.
7) Receives the processed information from RCP and accordingly drive SP & SN.
6. CALL PROCESSING:-
Call processing involves the interaction of the software modules in C-DOT 128 RAX with
hardware. Both the hardware and software must cooperate to bring about any successful
telephony event.
A local call sequence in the C-DOT 128 RAX can be described in the following 4 phases-
(A) ORIGINATION OF CALL:-
1) Subscriber ‘A’ lifts the hand set.
2) DC loop formed through HMT and DC current flows in line)
3) Flow of current is sensed by SLC card, Formation of loop on subscriber line reported
to Signal Processor (SP)
4) SP conforms the loop and reports to TIC by interrupt that subscriber has lifted the
handset.

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5) TIC records the identification of subscriber ‘A’ from status registers of Signal
Processor (SP).
6) TIC send the message to RCP through SP that subscriber ‘A’ has intention to
originate a call.
7) RCP analysis the number (port) & check the validity of number from its directory.
8) If invalid, then RCP informs TIC to send NU tone on that port and state of port
remains the same.
9) If valid, RCP informs TIC through tone processor to feed dial tone to subscriber
‘A'.Status of subscriber ‘A’ changes to busy. The state of subscriber is changed it in
the portable to dial begin state.
(B) DIALING:-
After getting dial tone, subscriber ‘A’ dials 1st digits.
1) On reception of 1st digit, TIC informs RCP; RCP checks 1st digit and informs TIC to
disconnect the dial tone to subscriber ‘A’.
2) If it is invalid, NU tone is fed to calling subscriber ‘A’.
3) If 1st digit is valid, it is stored on the space available in the corresponding port & the
digit counter is incremented.
4) After storing all the three digits RCP analysis the number and translates these 2nd and
3rd in to port number.
5) If the port is valid one, then RCP checks weather the called party port is free or not. If
it is not free then RCP inform TIC to feed busy tone to calling party and state is
changed in to busy state.
6) If the called party port is free, then RCP informs TIC through TP to feed ringing
voltage to called party port, the status of called party is changed in to busy state.
7) At this time subscriber ‘B’ is being rung and subscriber ‘A’ is getting ringing back
tone.
(C) RESPONSE OF CALLED PARTY & CONVERSION:-
1) As soon as subscriber ‘B’ lifts HMT, the ring is tripped by telephone itself by
disconnection of AC loop.
2) SP again validates OFF-HOOK condition, if it is reported to TIC.
3) TIC sends a message to RCP through TP (SP).

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4) RCP informs TIC through TP (SP) to connect ‘A’ and ‘B’ & state of subscriber is
changed to conversion.
5) An RCP increment the meter of the subscriber A and call is registered.
(D) DISCONNECTION:-
1) Subscriber ‘A’ goes “on hook”.
2) Line card detects the disconnection of loop by sending “Non Flow” of current in the
limbs.
3) This condition reported to SP.
4) SP reports the “on hook” condition Sub. ‘A’ to TIC.
5) TIC records the “on hook” condition & prepares message of disconnection and sends
it to RCP through TP reporting this message that sub. ‘A’ has cradled on HMT.
6) RCP sends a message to TIC through TP to disconnect subscriber ‘A’ & ‘B’.
7. MAINTENANCE PANEL (MP):-
Maintenance Panel has 7 function keys:
(1) Test
(2) Time
(3) Traffic
(4) Misc
(5) Trunk
(6) Subscriber
(7) Meter and has few sub function keys
The operating functions of MP are broadly classified in 5 main areas
(A) Subscriber administration
(B) Trunk administration
(C) Traffic administration
(D) Maintenance panel test
(E) Exchange parameter programming
The subscriber administration mode is entered with the entry of “SUB” key command. The
2nd level of “SUB” commands having digit keys 1 to 4 for different services areas.
● Adding subscriber

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● Removing subscriber
● Class of service for subscriber
● Class of service details of subscriber
Maintenance panel test is conducted by entry of “TEST” command, so that various functions
of hardware can be checked.
The supervisor’s access to modify a status is restricted by the use of a password. The access
is provided only if correct password is entered.
Facility of maintenance panel in C-DOT exchange:-
● Traffic Measurement
● EPROM is used for office data & metering information
● Office data and other data can be altered easily through password
● Restriction can be imposed on subscriber services.
● Public phone can be provided with charge.
● Trunk offering
● Selective trunk blocking
● Display for line and trunk lockout
● Exchange status can be inquired through dialup
● Ring down alarm reporting
● Line testing
● Maintenance alarm
● Total failure alarm
8. INTERACTIVE VOICE RESPONSE-SYSTEM (IVRS):-

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Fig 8.1: I V Response System
The system in which the information available in the computer is retrieved by the user in the
form of voice with the help of interaction between telephone and computer is known as
‘Interactive Voice Response System’.
With the help of this system information regarding public reservation; arrival /departure of
train; fare can be delivered to user when and where it is asked through telephone.
Each section control office id having a computer called DATA ENTRY COMPUTER along
with dial up/lease line modem is used for linking the computer of other control offices either
directly or through server. Each control office computer is identified as cheek/data entry
point.
At place where the information is to be retrieved through telephone, another computer linked
with data entry computer called IVRS COMPUTER, which is connected to data entry
computer by ETHERNET CARD. These computers read the information from data entry
computer and then convert it to voice for user purpose.
HARDWARE: - There are three types of hardware.
● DATA entry terminal computer
● Modem
● IVRS terminal (Computer)

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DATA ENTRY TERMINAL:-
It is a personal computer of more than 166 MHz, 16 MB RAM, 2.1 GB Hard Disk; 101 key
keyboards; a mouse and color monitor.
MODEM:-
The data entry terminals are linked with lease line/dialup modem of speed better than 33.6
Kbps.
IVRS TERMINAL:-
It is Pentium 133 MHz p.c. with 24 port dialogic cards called IVRS card capable to respond
on both pulse and tone. Out of 24 ports-: 4 ports are used for voice and FAX on demand; 2
ports are used for railway PSTN lines; 2 ports are used for fare inquiry and rest 16 ports are
used for train inquiry.
SOFTWARE:- There are three types of Software.
● COPETS SOFTWARE
● COMMUNICATION SOFTWARE
● OLTRIS SOFTWARE
COPETS SOFTWARE:-
It is friendly user software, which is used to record the train schedule timing information in
data files.
This software is having following facilities_:
1) The system is secured by stages of password facility
2) It is having the facility for data entry of running/schedule time.
3) Entry for expected arrival/departure.
4) Addition and removal of data entry points.
5) Addition and removal of train in the system.
6) Changes In the database for timetable; fare table etc.
7) It restrict the entry of the train after a specific period i.e. the file is detected for a train
after 2 hours of its arrival; and deletes the files which are 48 hours old and
restructure/recognize the files.
8) This software is having a facility to generate the report of-:
(A) Status of running train as per—

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❖ According to train
❖ According to control office
❖ As per a specific interval.
(B) Information of train, when the train is late.
(C) It also shows the train graph.
(D) Summary of any train running over the month.
COMMUNICATION SOFTWARE:-
This software works on the principle of packet switching in which each train file is developed
in the form of packet along with destination address. In IVRS system Delhi Central Computer
acts as HUB and it will dial or connect through leases line after a specific interval to the data
entry computer of different control offices and exchanges the files with them.
When a pop file is generated after every 15 minutes in data entry computer, then file is
transferred to its queue directory. When HUB computer is connected to the data entry
computer, HUB searches the file from queue directory and down load in it’s receive directory
and similarly the queue directory files available in the HUB will be received and stored by
the data entry computer. By this way the queue directory files are exchanged and updated.
The communication software is also heaving the facility for CRC (Cyclic Redundancy
Check) check and receive check so in case of line failure or modem faulty, when the file
could not be exchanged, then HUB try to establish the link & if it is not able to exchange,
Then it will create alarm and show link break.
This software is having following facilities_:
1) Auto dialing facility for origination of transmission of information.
2) Heaving facility of auto pickup of file from remote queue directory
3) Facility of auto transfer of own file to remote/required place.
4) Facility of transfer of file as per priority decided by HUB.
5) It has facility to support WAN and is capable of interfacing with any type of
communication system like Internet, VHF and UHF.
6) Facility of monitoring of transe and receive files.
7) It is provided with the list of transmitted files and remaining files.

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OLTRIS SOFTWARE:-
The main aim of the system is to provide “ON LINE TRAIN RUNNING INFORMATION”
like termination of the train before schedule; changed the route of the train; accident of train;
abnormal delay/late of the train and so on. So the software is developed to support all the
abnormal activity.
This software is having following facilities_:
1) It is heaving the facility to interact with both pulses and tone users.
2) It is heaving the facility of FAX on demand, for that separate terminal is provided
3) It is supporting and selects more than one language.
4) According to traffic, ports can be increased or decreased.
5) It is heaving the facility of mailbox.
6) It is heaving the facility of according the calls on each port and gives a report of
number of calls in 24 hours.
9. PASSENGER RESERVATION SYSTEM (PRS):-
Computerized passenger reservation system is a most useful facility, which enhances the
image of Indian railways in public. It is an efficient and dynamic network of reservation all
over the India. Initially it is installed in Delhi by CRIS and for western & central railways a
common super computer is installed in CSTM and the trains of both railways is programmed
on this computer.
The main super computer which installed at CSTM and the terminals of both different
locations connected to this computer with communication link through OFC, UHF, and MW
on 4wire/2wire analog speech channel, digital 64 Kbps channels with the help of MUX,
modem and 3601, 3603, 3608 of Indchem DINC circuits.
When the more then one terminal is required at a place then either 8 terminal modem Mux,
called CODEC is used. Some mixes can multiplex the data of 12 terminals like DCM Mux.
But some of the mux are requiring more than one analog channel like in DCM; where 2
channels are require which support 20 or 24 terminals.
In PRS, there is only one set of computers in which all the information regarding the train
coaches reservation, fare, status are available and terminal can access these computers from
remote location for registration, inquiry of reservation and data for printing the chart and the
ticket.

20. 20
The terminals are access through mux & modems. At present there are 5 main computer
frames i.e. CSTM, DLI, HWH, DS, MAS and all the computers are interconnected to each
other with 64 Kbps through lease line modem and each set of computers are heaving the
terminals spreading over their jurisdiction. So any of the terminals access any of the train of
Indian railway originated from any of place.
Fig 9.1: Concert Network Topology
10. CSTM MAIN FRAME COMPUTER:-
The PRS main frame computer is installed at CSTM at passenger reservation center. It
consists ‘4’ severs connected to each other in cyclic order and all the servers share a
common stored memory i.e. a group of 70/80 hard disks installed in rack. But they can
access any of the hard disk for writing the information.
The main server is connected to slave servers of DSE in CSTM are about of 200 of 16 or
32 ports of speed 4800 bps. The DCE terminal can be connected to node which ID and
prompt to each terminal. Each slave server can accommodate 16 or 32 ports or terminals.
These servers are connected to main frame computers through ether net cable by ‘T’
connections or through multiplexer, which can accommodate 8 or 16 DCE servers.
The total numbers of slave server i.e. through RJ11 connector if the type of channel. If
use analog than the SQ should be 9 and SNR should be 39 of company DCM or CODEC,
but if digital system is used then GYGNUS Mux modems are used. Here a connectivity of
Ahmedabad is shown where at CSTM and the server ports are multiplex in GYGNUS 516

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multiplexer which can accommodate 8/16 terminals along with 2 voice ports and the
output is composite signal of 14.4 Kbps. These composite signals of about 12 muxes are
again multiplex by another multiplex of and the output can be transmitted through media
i.e. the 64 Kbps channel is transmitted through railway and 9.6 Kbps is through DOT
circuits.
Now a day PRS being a very popular passenger amenity, so that S & T is required to
maintain its data and analog channel. Very efficiently with very close tolerance and a
slight interruption result in stoppage of reservation….
11. RAILNET
The net works used railways are-:
1) Rail-net.
2) FOIS: - Freight operation and information system.
INTRODUCTION:-
Indian railways has decided to set up their own Corporate Wide Information System
(CWIS) called RAILNET to provide computer connectivity bw railway board with zonal
railways, Production units, centralized training and 46 major training institutes.
For improvement in this network in terms of bandwidth, quality of channel, Indian railways
setup a separate organization i.e. “Indian Railways Central Organization of
Telecommunication (IRCOT)...
ORGANIZATION:-
● First rail-net was established bw Railway Board, 9 Zones, 6 Production units in
phase 1.
● Than extended to 6 new zones, 5 centralized training institutes, research &
development and standard organizations, metropolitan transport projects in phase 2.
● The divisional officers, Zonal training institutes will be connected to rail net in phase
3 and finally to station, yards, shades etc….

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RAIL-NET COMPRISES:-
Intra-net-
Intra-net is an internet network of Indian railway allowing the railway officers and staff to
communicate on this digitized network.
Inter-net-
Internet allows user to get into a global communication method and global pool of
knowledge, advertisement and entertainment through www (World Wide Web) is a secured
manner.
TOOLS:-
● E-Mail.
● EDI (Electronic data interchange)
● WWW
● FTP (File Transform Protocol)
● TCP (Transmission control protocol)
OBJECTIVES:-
Rail net is used to provide following services—
1) Creation of web pages.
2) E-Mail.
3) Electronic transfer of data used for monitoring and co-ordinate purpose.
4) Voice-over IP.
5) Video-conferencing.
6) Web-based application software development.
7) Fax services.
8) Web surfing (Browser usage for internet and intranet).
9) Change from “PEROIDIC REPORTING” to “INFORMATION ON DEMAND”.
10) Facilitate quick and efficient automatic status update bw Railway Board & Zonal
railway through our own “Intra Railway Network (RAILNET).

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RAIL-NET GENERAL ARRANGEMENT:-
● Procurement installation & Commissioning of server, Router, Switches, Modem etc…
● Testing and Commissioning of DATA links.
● Loading and Configuration of system software.
● Training of railway personnel as per contract agreement Zonal railways
● Established their Local Area Network (LAN).
● Arrange for data circuits on railway / dot hired channels.
● Maintenance of rail net infrastructure as well as Web-Pages
HARDWARE COMPONETS:-
● Servers.
● Routers, Switches & Hubs.
● Structured cabling using UTP-CAT 5 cabling
SOFTWARE COMPONENTS:-
● MS Windows NT Server (Operating system for server)
● MS Windows NT Work station 4.0 (Operating system for work station)
● Internet information server 3.0 (Administrates internet access in LAN)
● Front page express 98 (For designing of web pages)
● Lotus nodes clients 4.6 (Provides E-mail facility to local users)
● Cisco works with SNMPC (Administrate router)
● Cisco fire wall (Provides safely to railway information)
● NMS (Administrate FOIS)
12.NETWORKS COMPONENTS:-
1)SERVER:-
A network is a multi-user system because more than one person at a time can send
request to a machine. A shared machine together with the software programs, which handles
requests and distributes the networks resources such as data files printer times both the
machine and its software are jointly referred as the server.
Server has following characteristics-
● Hardware including motherboard of the server is entirely different from a normal P.C.

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● It can be used with two processors of 500 MHz.
● It contains 3 hard disks having capacity of 9 GB. These are connected to the
motherboard RAD controller card.
● A server should be able to implement security for its data.
It contains Microsoft Back Office Server 4.01 software which comprises following
programs
● Microsoft NT.
● Microsoft Back Office.
● Site management server.
● Proxy software.
● Server network administrate
● Exchange server.
2) ROUTER:-
A router translates information from one network to another. It is similar to a super
intelligent bridge. Routers select the best path to route a massage, based on the
destination address and origin. The router can direct traffic to prevent head on
collisions.
Routers know the addresses of the computers, bridges, and other routers on each side
of the network.
Routers can:-
● Direct signal traffic efficiently.
● Route messages bw any two protocols.
● Route messages bw linear bus, star and star-wired ring topologies.
● Route messages across fiber optics, coaxial & twisted pair cabling.

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Fig 12.1: Network Components
3) SWITCH:-
The switch is used to interconnect the nodes. But it is more complex, versatile and
also there is no division of bandwidth among the nodes.
They are active device with following points…
● 10 Mbps, 100 Mbps, single speed or dual speed operation.
● Congestion control, which means that the switch should enough buffers to take care of
the traffic peaks.
● Segmentation of local network.
● Speed up the local network. They are of 8, 16 or 48 ports active terminals.

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Fig 12.2: Switch
(4) FIREWALL:-
It is security purpose software, which is used to secure the server contents, so the outside
user could not temper the information; the user can read the information but cannot write
anything.
(5) HUB:-
It is active junction box, which is used to connect the nodes and all the servers using any
type of cable (UTP, coaxial etc). It contains a division of network bandwidth. The important
parameters to be considered whole selecting are-:
● Support for dual-speed operation.
● Number and types of ports, UTP & BTC.
● Auto switching.
● Support a built-in segment switch.
● Ease of configuration.
It can capacity of 8, 16 or 24 nodes and the maximum distance bw Hub and nodes is 100 Mt.
If distance is more, than additional HUB must be used (but not more than 3)…

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Fig 12.3: Hub
(6) NETWORK INTERFERENCE CARD:-
It is a device having intelligence to control access to the networks and enable communication
across the network. Through NIC the nodes are connected functionally and physically to the
network. It is also called network adapter. In a LAN each device is attached to the shared
transmission medium through a network interference card (NIC). It contains logic for
accessing the LAN and for sending and receiving blocks of data on the LAN.
13. MEDIUM OF COMMUNICATION:-
The medium of communication with stations are of two types:
● Through overhead lines.
● Through Optical fiber cable.
(1) OVER HEAD LINES:-
The over head lines are joining two stations through the poles. These poles are placed near
the railway track. The over head lines are running over the poles. The over head lines have
low insulation compared to optical fiber cable. The communication can be failed when the
line breaks due to sand storm or fall of poles.

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(2) OPTICAL FIBER CABLE:-
This is an underground line process. In this communication the message will be sent to one
place to another place is in the form of “Light Energy”. This light is in the form of infra red.
In this communication the glass fiber cable is used on the place of cable wire which is
transporting light energy from one place to another. Light energy is in the form of a code, just
like a bulb which is ON-OFF continuously.
In this system at transmitting station the speech signal, data etc. are modulated by pulse code
modulation and by this technique many channels are connected through time division
multiplexing. Now these electric pulses are converted in to the optical signals and send to
another places using optical fiber. At receiving station the optical signal converted in to the
electronic signal. Now the speech signal, data etc are demultiplexed and then send to another
subscriber.
ADVANTAGES OF OFC’S:-
● Losses in fiber cable are minimum so the repeater stations are far apart.
● Channel capacity is more
● There is no effect of electromagnetic radiations, radio frequency and electrical
noise.
● Cable is light in weight and thin.
● There are no current flows through it so it is safe.
● In the term of security it is best suited.

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Fig 13.1: Optical Fiber
Fig 13.2: Wave Propagation In OFC

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14.BLOCK DIAGRAM OF OPTICAL FIBER CABLE
COMMUNICATION ARRANGEMENT:-
Fig 14.1: Communication through OFC
The diagram shows the OFC communication system. The working of the system is as
follows:-
MULTIPLEXER:-
Signal can be changed into the digital codes using PCM. Now each channel collected &
multiplexed using time division multiplexing and creating a digital base band.
OPTICAL LINE TERMINAL EQUIPMENT (OLTE)-
It converts the digital signal in to the light signal. In this equipment, using a laser diode
which converts digital signal in to light signal. Now this light signal feed in to the optical
fiber cable using pigtail connector.
SPLICE:- It connects two optical fiber cables together.
REGENERATOR:- If cable is too long then regenerators are used to overcome the
losses.
PHOTO DIODE:- The light signal from optical optical fiber cable can be converted in
to the electrical signal.

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DEMULTIPLEXER:- Now these electrical signals can be demultiplexed using
demultiplexer and separating all channels and given to the subscriber. For one link there is
two optical fiber needed. One for transmitting side & another for receive side.
15. DUAL TONE MULTI FREQUENCY (DTMF):-
To control trains there is a communication bw the controller and station master. This
communication provided by DTMF. Dual Tone Multi Frequency (DTMF) is also known as
touch tone or touch dialing. It is used for telephone signaling over the line in voice frequency
band to the call switching center. DTMF is an example of a multi frequency shift keying
(MFSK) system. Today DTMF is used for most call setup to the telephone exchange. The in
band trunk signaling tones were different from the tones known as touch tones with a
triangular matrix being used rather than a square matrix.
DTMF was developed at bell labs in order to allow dialing signals to dial tones distance
numbers, potentially over non wire links such as microwave links or satellites.
Encoder/Decoders were added at the end offices that would convert the standard pulse signals
in to DTMF tones and play them down the line to the remote end office. At the remote side
another encoder/decoder would decode the tones and perform the pulse dialing. This idea of
using the existing network for signaling as well as the message is known as in-band-
signaling.
The touch tone system also introduced a standardized keypad layout. After using 18 different
layouts, they eventually chose the one familiar to us today with 1 in the upper-left and 0 at
the bottom. The adding-machine layout, with 1 in the lower left was also tried but at that time
few people used adding machines.
The engineers had also envisioned phones being used to access computers, and surveyed a
number of companies to see what they would need for this role. The led to addition of the
number sign (#) and star (*) keys as well as a group of keys for menu selection A, B, C, and
D. In the end the lettered keys were dropped from most phones, and it was many years before
the # and * keys became widely used. Many non-telephone applications still used the
alphabetic keys, such as amateur radio repeater signaling and control.
The U.S. Military also used the letters, relabeled, in their now defunct auto on phone system.
Here they were used before dialing the phone in order to give some calls priority, cutting in
over existing calls if need be. The levels of priority available were Flash Override (A), Flash
(B), Immediate (C) and priority (D), with flash override being the highest priority.

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Present-day uses of the A, B, C and D keys on the telephone networks are few. For example
the A key is used on some networks to cycle through different carriers. Their use is probably
prohibited by most carriers.
DTMF tones were also used by some cable television networks to signal the local cable
company to insert a local advertisement.
Keypad of DTMF:-
The DTMF keypad is laid out in a 4 x 4 matrix, each row is presenting a low frequency and
each column representing a high frequency. Pressing a single key such as ‘1’ will send a
sinusoidal tone of two frequencies 697 and 1209 hertz (Hz). The two tones are the reason for
calling it multi frequency. These tones are then decoded by switching center in order to
determine which key was pressed…
DTMF keypad frequency (With sound clips):
DTMF Event frequencies:
Event Low frequency High frequency
Busy signal 480 Hz 620 Hz
Dial tone 350 Hz 440 Hz
Ring back tone 440 Hz 480 Hz
16. SIGNALLING DEPARTMENT
INTRODUCTION:-
The important part of operating the train in railways is signaling. The operators of
interlocking systems should go through certain events like signals, points, tracks, slots,
routers, buttons etc, to offer a signal. In the cause of unfortunate accidents due to mishandling
of the signaling process or due to faulty instruments, the railway authorities have to inspect
all these parameters.“ROUTE RELAY INTERLOCKING SYSTEM”, as name suggest
clear the route in its jurisdiction, for train movement by giving various signals through rely
operation and then interlocks that rout to avoid accidents. It also logs the current status of

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each relay, and route using DATA LOGGER and keeps this information in records for further
use.
The operator at the m/w tower receives the information of train departure from or train
arrival at the nearest station through block instrument. This instrument is connected to the
block instrument of nearest station via overhead lines running along the railway track.
The relay room at tower consists of a large mesh of relays of various ratings, connected
together in a very complicated manner. Making and breaking of contacts of various relays
results in the various signal indication.
For signaling, the railway tracks are used as conductors and a 2V DC supply is always
available across the track. As a train moves on a certain track, the parallel tracks are short
circuited by the conducting wheels of the train and current flowing through them operates the
track relay which in turn gives indication on the control panel.
DATA LOGGING SYSTEM:-
The DATA LOGGER is a microprocessor based system which logs all the events that occur
in the yard and make easier for railway authorities to inspect the system with the help of
software reports. This acts like a black box, which stores all the information regarding the
changes taking place in relays. The same information can be transformed to the computer to
analyze further. On line analysis of logged data can also be done and hence the preventative
maintenance can be achieved.
This logged online information y the data loggers will be processed with the help of software
in order to empower the monitoring system of railways in the areas faults, signaling
mechanism, reports of behavior of signals in various dimension like time, route etc.
The networking feature of data logger enables to connect all the data loggers through
communication channel and information. The data can be sent in both directions UP and
DOWN. This network of data loggers is connected to a system called FRONT END
PROCESSOR (FEP), which receives the data, transmitted by data loggers. FEP is turn
connected to a computer which placed in the control room.
So the software “NETWORK MANAGEMENT OF DATA LOGGERS” is implemented
to manage this networked data logger system and thus by providing online information of
data collected by the data loggers. It was developed in 98 DELPHI 4.0 on WINDOWS
operating system.

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Various provisions are given for railways to utilize the online information processing
capacity of this software. The provisions are:-
● To get online reports of the status of various signals operating the yard with real time.
● To get the online faults occurring to assist the personal to expect the frothing
problems due to the faults signal operating mechanism as well as correct the
equipment.
● To get the scenario of yard layout with the help of a simulated yard environment
reflecting online and offline status of various signals.
The data loggers are connected with specified no. of digital inputs & analog inputs. (Data
logger has capacity to connect 4096 digital & 64 analog inputs). Digital inputs are scanned
for every 16 mile seconds. Analog signals are scanned for every 16 seconds in the case of 32
analog signal input & 32 second for 64 analog inputs. The care has been taken to provide
necessary de-bounce time required for digital inputs.
There can also be Mini data logger connected in the n/w. These are built around 8085
microprocessor for performing various operations like data scan, data transmission. These
mini data loggers have the capacity to connect 32 digital & 16 analog inputs.
The technology can be better described with a block diagram, components of it and
communication between the components…
BLOCK DIAGRAM:-
Fig15.1: Block Diagram of DATA LOGGER

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COMPONENTS:-
The system comprises the following components as shown in the above figure.
FRONT END PROCESSOR (FEP):-
The FEP is built around MOTOROLA 6800 microprocessor. It has a memory of 8 mega
bytes for data storage. The FEP has 4 serial ports, one of them is connected to the computer
and remaining 3 are used to connect to the network of data logger. The main function of FEP
is to receive data from logger or mini data logger and store in its memory & transfer the same
to the computer.
COMPUTER AT CONTROL ROOM:-
The computer is based on latest Pentium processor with a minimum speed of 300 MHz, a
RAM of 64 MB, and a hard disk with minimum capacity of 2.1 GB. This computer is loaded
with the software developed for the network data logger system. The main function of this
computer is to receive the data online from FEP, process it & update respective screens with
results & save the data.
MODEM:-
The modems are four wires leased line type & are used for data transfer bw the data logger
and FEP. These modems have their own built in strong communication protocols. They have
various data transfer rates ranging from 300 bps to 19.2 kbps. The modems are connected to
each data logger through standard RS232 communication.
COMMUNICATION:-
In the case of single data logger placed in the station, it is directly connected to the
computer located in control room via standard current loop communication. In the case of
networked data logger, the computer placed at the control room. It will take the data received
by FEP.
If the network is in unidirectional mode, each data logger in the network will send its own
data collected at its location and the data received from the data the data loggers is placed
into FEP. If the network is in bidirectional mode, each end of the network is connected to the
FEP.

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If the data loggers are placed at long distance (between 3 km and 20 km).The
communication is through modems and if they are placed at short distance (Below 3 kms )
current loop communication technology is used…
DATA LOGGER:-It consists of:
● MOTOROLA 6800 CPU CARD.
● DIGITAL SCANNER UNITS.
● ANANLOG SCANNER UNITS.
● LCD DISPLAY & HEYBOARD.
● REAL TIME DISPLAY WITH 7 SEGMEN.
● LED DISPLAY FOR ONLINE STATUS DISPLAY.
● PARALLEL PORT.
● SERIAL PORT.
● EXTERNAL DISPLAY.
MOTOROLA 6800 CPU CARD:-
This is the central processing unit which performs all activities pertain to data logger i.e.
scanning of digital signal for every 16 m sec. and scanning of analog voltage for every 16
sec. This CPU card will support LCD, LED matrix display and real time clock. The CPU
keeps on scanning all the digital and analog scanner units.
Each input connected to the scanner unit and scanner unit connected to the particular opto
coupler.When it scans, it checks the output of the optocoupler to find if there is any deviation
from the previous status and stores the status with real time.
Whenever there is change in position of input of the scanner unit from its previous position,
the real time data of the output is noted. In this manner the data is logged and stored.
DIGITAL SCANNER UNITS:-
Each scanner unit contains 4 or 8 cards depending upon the type of scanner card connected.
The potential free contacts terminated by tag block from the relays of signals, track points
and buttons are connected to these scanner cards. These scanner cards contain multiplexers
for addressing the inputs and opto isolators for input isolation. Every scanner card serve up to
64 or 32 or 16core color coded flat cable ribbon, so totally each DU can cater up to 512 or
256 inputs.

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ANANLOG SCANNER UNIT:-
For each data logger the ANANLOG SCANNER are provided to scan the analog inputs.
Each ASU can cater 8 or 4 depending upon the inputs AC or DC connected. For DC voltages
8 inputs ASU will be connected. For AC voltages 4 input ASU with step up transformer will
be connected. The scanner units contains signal conditioning signals, buffer amplifies,
analogdigital converters and isolation circuits. Each input requires 10 mA for exsiccation.
LCD DISPLAY & KEYBOARD:-
The LCD display & keyboard acts as machine interference bw user and data logger, for
efficient management of this data system. All the software operations, which can be
performed using this LCD and keyboard, are explained.
REAL TIME DISPLAY WITH 7 SEGMENTS:-
There is a built in real time clock within the data logger and its current time will be displayed
on 6 or 7 segment display provided. There is a blinking dot indicating the seconds. The real
time clock is depending upon DALLAS 1286 chip which is known for its application in
computers. This IC will come with internal battery back up; hence there is no need to add
external battery.
LED DISPLAY FOR ON LINE STATUS DISPLAY OF RELAYS:-
Flat matrix LED display was provided for on line viewing of relay status. Total of 512 relay
status can be viewed at any moment.
PARALLEL PORT:-
The parallel port can be connected to a printer to tag hard copies of all the events recorded.
SERIAL PORT:-
The total of 4 serial ports is provided. One port is used to link the computer and data logger.
One port will be used to interface display board to show relay status. Two ports are used to
link the data logger on to bidirectional communicational channel.

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EXTERNAL RELAY & TELE CONTROLS:-
There is relay provided on the CPU card whose 2 number contacts are available on the rear
panel to extent the alarms to remote location. 14 tele controls are provided to control 14
external relay from computer. A 25 pin mail connector is provided for tele controls and relay
controls. Each input sinks 100 mA of current.

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17.BIBLIOGRAPHY:- Study guide of Railway’s trainers
1. http://en.wikipedia.org/wiki
2. http://www.comit.com
3. http:www.silicon logic.com
4. http://www.cadence.com
5. http://www.ece.msstate.edu/
6. http://www.onesmarlclick.com