i

A Report on

Industrial visit

At

Loco Workshop

Ajmer Submitted

In partial fulfillment For the award of the Degree of

Bachelor of Technology

In Department of Computer Science and Engineering

Submitted To: Submitted By:

Dr. Rakesh Rathi Vinita Head of Department 11EEACS090

Computer Science and Engineering

Department of Computer Science and Engineering

GOVT ENGINEERING COLLEGE AJMER December, 2014

ii

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, Bikaner 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.

iii

ACKNOWLEDGEMENT

I have taken efforts in this visit. This is opportunity to express my heartfelt words for the

people who were part of this visit in numerous ways, people who gave me unending support

right from beginning of the training.

I would like to take this opportunity to express my deepest gratitude to the people, who has

contributed their valuable time for helping me to successfully present this seminar. With great

pleasure and acknowledgement, I extend my deep gratitude to honorable Dr. Rakesh Rathi,

(Head of Department CSE), Govt. Engineering College, Ajmer for giving me opportunity to

present my seminar.

It is my profound privilege to express my deep gratitude to and Sh. S.N. Tazi, (Associate

Professor) for precious guidance, constructive encouragement and support regarding

seminar.

Finally, I would like to thank to all staff members, classmates of CSE and all people who

were directly and indirectly involved in the activity. My thanks and appreciations also go to

my colleague in this visit and people who have willingly helped me out with their abilities.

VINITA

(11EEACS090)

iv

CONTENTS

TITLE PAGE

ABSTRACT

ACKNOWLEDGEMENT

CONTENTS

FIGURE INDEX

ii

iii

iv

vii

CHAPTER-1 HISTORY OF LOCO WORKSHOP 1

CHAPTER-2 INDIAN RAILWAY 2

1.1 Introduction To Railway 2

1.2 Railway Zones Headquaters 2

CHAPTER-3 NETWORKS COMPONENTS 3

2.1 Introduction 3

2.2 Server 3

2.3 Router 4

2.4 Switch 5

2.5 Firewall 6

2.6 Hub 6

2.7 Network Interference Card 7

CHAPTER-3 MEDIUM OF COMMUNICATION 8

3.1 Medium Of Communication 8

3.2 Over Head Lines 8

3.3 Optical Fiber Cable 8

3.4 Block Diagram Of Optical Fiber Cablecommunication Arrangement 10

v

3.5 Dual Tone Multi Frequency (Dtmf) 11

CHAPTER-4 SIGNALLING DEPARTMENT 13

4.1 Introduction 13

4.2 Data Logging System 13

4.3 Front End Processor (Fep) 15

4.4 Computer At Control Room 15

4.5 Modem 16

4.6 Communication 16

4.7 Data Logger 16

CHAPTER-5 CALL PROCESSING 19

5.1 Introduction 19

5.2 Origination Of Call 19

5.3 Dialing 20

5.4 Response Of Called Party & Conversion 20

5.5 Disconnection 21

CHAPTER-6 NETEWORK CARDS 22

6.1 Function Of Important Cards 22

6.2 Psu Card 22

6.3 Subscriber Line Card (Slc Card) 22

6.4 Tone Generator & Diagnostic Card (Tgd) 24

6.5 Control Cards 24

6.5.1 Racks Control Card 25

6.5.2 Tic Card/ Sn (Switching Network) 25

vi

CHAPTER-7 EXCHANGE AND INTERACTIVE VOICE RESPONSE SYSTEM 27

7.1 Automatic Electronic Exchange 27

7.2 C-Dot Electronic Exchange 27

7.3 Interactive Voice Response-System (Ivrs) 29

7.4 Hardware 30

7.4.1 Data Entry Terminal 30

7.4.2 Modem 30

7.4.3 Ivrs Terminal 30

7.5 Software 30

7.5.1 Copets Software 30

7.5.2 Communication Software 31

7.5.3 Oltris Software 32

CHAPTER-8 RAILWAY NETWORK 34

8.1 Introduction 34

8.2 Organization 34

8.3 Rail-Net Comprises 34

8.4 Tools:- 35

8.5 Objectives 35

8.6 Rail-Net General Arrangement 35

8.7 Hardware Componets 36

8.8 Software Components 36

8.9 Passenger Reservation System (Prs) 36

CONCLUSION 38

vii

FIGURE INDEX

FIGURE NAME PAGE NO.

FIG 2.1 NETWORK COMPONENTS 4

FIG 2.2 SWITCH 5

FIG 2.3 HUB 6

FIG 3.1 OPTICAL FIBER 9

FIG 3.2 WAVE PROPAGATION IN OFC 10

FIG 3.3 COMMUNICATION THROUGH OFC 10

FIG 4.1 BLOCK DIAGRAM OF DATA LOGGER 15

FIG 7.1 I V RESPONSE SYSTEM 29

FIG 8.1 CONCERT NETWORK TOPOLOGY 39

viii

Chapter-1

BRIEF HISTORY OF AJMER LOCO AND AJMER CARRIAGE

WORKSHOPS

The foundation of the prestigious Central workshop was laid in 1876 and was

Established in 1877 to undertake repairs and manufacturing of steam

Loco motives, carriages and wagons of Rajputana-Malwa MG system. In the year

1885 onwards, these shops came under BB&CI company. It had the privilege of

producing 467 steam locomotives during 1896-1949, including 20 locomotives of

XTI type. Production of new locos stopped in 1950 when Chittaranjan Locomotive

Works was set up. This workshop started Periodic Overhaul (POH) &

Intermediate Overhaul (IOH) of MG steam locomotives and ART steam cranes

(35 ton) in 1970. However, POH of MG ART Steam crane is continuing till date.

POH of MG diesel locomotives started in 1979. POH of MG steam Locos was

stopped in 1999. MG wagon POH activity was shifted from C&W Workshop,

Ajmer to Loco Workshop with effect from January 2000. Loco workshop has

been renamed as Ajmer Diesel Loco and Wagon Workshop (ADLW) and C&W

shop as Carriage Shops. POH/IOH of BG Diesel locomotives commenced

regularly from July’06 and the first BG Diesel Loco after POH was turned out from

the shops in January 2007.

24

Carriage and Wagon Workshop was built in 1884 for repairs and

manufacture of Carriage and Wagon for the Rajputana-Malwa Railway. This

workshop has proud privilege of being the first workshop in the country to set

up facilities in 1902 for production of steel castings. The manufacturing of new

coaching and wagon stock continued in this workshop till the setting up of

Integral Coach Factory and till development of certain private & public sector

factories for manufacture of wagons. This workshop was modernized during

1986-92 at a cost of Rs.31.81 crores. This workshop also carries out POH of Palace

on Wheels and Heritage on Wheels. This workshop stopped POH of MG wagons

from Dec.’99 and the activity was shifted to Loco workshop. Both Carriage and

loco workshops are ISO 9001: 2000 certified.

1

Chapter-2

INDIAN RAILWAY

2.1 INTRODUCTION TO RAILWAY

Indian Railways is an Indian state-owned enterprise, owned and operated by the Government

of India through the Ministry of Railways. Railways were first introduced to India in 1853

from Bombay to Thane. In 1951 the systems were nationalized as one unit, the Indian

Railways, becoming one of the largest networks in the world. IR operates both long distance

and suburban rail systems on a multi-gauge network of broad, meter and narrow gauges. It

also owns locomotive and coach production facilities at several places in India and are

assigned codes identifying their gauge, kind of power and type of operation. Its operations

cover twenty nine states and seven union territories and also provide limited international

services to Nepal, Bangladesh and Pakistan.

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--

2.2 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

2

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. East central Railway Hazipur

17. South East Central Railway Bilaspur

3

Chapter-3

NETWORKS COMPONENTS

3.1 INTRODUCTION

Networking hardware may also be known as network equipment or computer networking

devices. Typically, networking hardware includes gateways, routers, network

bridges, switches, hubs, and repeaters. But it also includes hybrid network devices such

as switches, protocol, bridge routers, proxy servers, firewalls, network address

translators, multiplexers, network interface controllers, controllers, modems, ISDN terminal

adapters, line drivers, wireless access points, networking cables and other related hardware.

3.2 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

1) Hardware including motherboard of the server is entirely different from a normal P.C.

2) It can be used with two processors of 500 MHz

3) It contains 3 hard disks having capacity of 9 GB. These are connected to the motherboard

RAD controller card.

4) A server should be able to implement security for its data.It contains Microsoft Back

Office Server 4.01 software which comprises following programs

5) Microsoft Back Office.

6) Site management server.

7) Proxy software.

8) Server network administrate

4

3.3 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

1) Direct signal traffic efficiently.

2) Route messages b\w any two protocols.

3) Route messages b\w linear bus, star and star-wired ring topologies.

4) Route messages across fiber optics, coaxial & twisted pair cabling.

Fig 2.1 Network Components

5

3.4 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…

1) 10 Mbps, 100 Mbps, single speed or dual speed operation.

2) Congestion control, which means that the switch should enough buffers to take care of the

traffic peaks.

3) Segmentation of local network.

4) Speed up the local network. They are of 8, 16 or 48 ports active terminals.

Fig 2.2 Switch

6

3.5 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.

3.6 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-:

1) Support for dual-speed operation.

2) Number and types of ports, UTP & BTC.

3) Auto switching.

4) Support a built-in segment switch.

5) Ease of configuration.

It can capacity of 8, 16 or 24 nodes and the maximum distance b\w Hub and nodes is 100 Mt.

If distance is more, than additional HUB must be used (but not more than 3)…

Fig 2.3 Hub

7

3.7 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.

8

Chapter-4

MEDIUM OF COMMUNICATION

4.1 MEDIUM OF COMMUNICATION

The medium of communication with stations are of two types:

1. Through overhead lines.

2. Through Optical fiber cable.

4.2 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.

4.3 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:-

1) Losses in fiber cable are minimum so the repeater stations are far apart.

2) Channel capacity is more

9

3) There is no effect of electromagnetic radiations, radio frequency and electrical

noise.

4) Cable is light in weight and thin.

5) There are no current flows through it so it is safe.

6) In the term of security it is best suited.

Fig 3.1 Optical Fiber

10

Fig 3.2: Wave Propagation In OFC

4.4 BLOCK DIAGRAM OF OPTICAL

FIBERCABLECOMMUNICATION ARRANGEMENT

Fig 3.3 Communication through OFC

The diagram shows the OFC communication system. The working of the system is as follows:-

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.

11

Photo Diode:-The light signal from optical fiber cable can be converted in to the electrical

signal.

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.

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.

4.5 DUAL TONE MULTI FREQUENCY (DTMF)

To control trains there is a communication b\w 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

12

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.

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.

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.

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 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

13

Chapter-5

SIGNALLING DEPARTMENT

5.1 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

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.

5.2 DATALOGGINGSYSTEM

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

14

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.

Various provisions are given for railways to utilize the online information processing

capacity of this software. The provisions are:-

1) To get online reports of the status of various signals operating the yard with real time.

2) 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.

3) 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.

4) 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.

15

5) The technology can be better described with a block diagram, components of it and

communication between the components

BLOCK DIAGRAM:

CONTROL RELAY

ROOM ROOM

Fig 4.1 Block Diagram of DATA LOGGER

COMPONENTS

The system comprises the following components as shown in the above figure.

5.3 FRONTENDPROCESSOR (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.

5.4 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.

PC PORT DATA

LOGGER

FEP

16

5.5 MODEM

The modems are four wires leased line type & are used for data transfer b\w 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.

5.6 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.

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…

5.7 DATALOGGER

It consists of:

1) MOTOROLA 6800 CPU CARD.

2) DIGITAL SCANNER UNITS.

3) ANANLOG SCANNER UNITS.

4) LCD DISPLAY & HEYBOARD.

5) REAL TIME DISPLAY WITH 7 SEGMEN.

6) LED DISPLAY FOR ONLINE STATUS DISPLAY.

7) PARALLEL PORT.

17

8) SERIAL PORT.

9) 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 opt coupler.When it scans, it checks

the output of the optcoupler 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.

Analog 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,

analog\digital converters and isolation circuits. Each input requires 10 mA for exsiccation.

18

LCD Display & Keyboard

The LCD display & keyboard acts as machine interference b\w 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 backup; 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.

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 cure.

19

Chapter-6

CALL PROCESSING

6.1 INTRODUCTION

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-

6.2 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.

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.

20

6.3 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.

6.4 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).

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.

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6.5 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’.

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Chapter-7

NETEWORK CARDS

7.1 FUNCTION OF IMPORTANT CARDS

The network controller implements the electronic circuitry required to communicate using a

specific physical layer and data link layer standard such as Ethernet, Wi-Fi or Token Ring

7.2 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

1) If current is more than 10 mA and up to 35 mA max, it is treated that subscriber has

lifted the handset.

2) 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.

1) +5V regulated (8Amp)

2) 12V regulated (1Amp)

3) -5V (0.1Amp) regulated

4) -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.

7.3 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

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to 2 SLC cards. One trunk card cannot 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.

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7.4 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.

The tones are

Table 6.1 Dial Tones with Specific Frequencies

7.5 CONTROL CARDS

These are 3 cards, which form a control network:-

1) RCP-RAX Control processor

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

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2) TIC- Terminal Interface Collector

3) 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

changeover is registered on the maintenance panel.

7.5.1 RACKS CONTROL CARD

Features

1) Main controller (Master)

2) Microprocessor 65C02 (C-MOS up)

3) Perform call processing, administrative & maintenance functions

4) Exchange database

5) Man-machine interaction through the maintenance panel (MP)

6) Communication link with the TIC, MP and duplicate RCP

7) Extensive system diagnostic

7.5.2 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.

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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.

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Chapter-8

EXCHANGE AND INTERACTIVE VOICE RESPONSE SYSTEM

8.1 AUTOMATIC ELECTRONIC EXCHANGE

Railway has its own communication system including microwave stations and automatic

electronic exchange.

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.

8.2 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:

1) 96 subscriber lines + 8 trunk (junction) lines.

2) 88 subscriber lines + 16 trunk (junction) lines.

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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

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.

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8.3 INTERACTIVE VOICE RESPONSE-SYSTEM (IVRS)

Fig 7.1 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.

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8.4 HARDWARE

There are three types of hardware.

1) DATA entry terminal computer

2) Modem

3) IVRS terminal (Computer)

8.4.1 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.

8.4.2 MODEM

The data entry terminals are linked with lease line/dialup modem of speed better than 33.6

Kbps.

8.4.3 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.

8.5 SOFTWARE

There are three types of Software.

1) COPETS SOFTWARE

2) COMMUNICATION SOFTWARE

3) OLTRIS SOFTWARE

8.5.1 COPETS SOFTWARE

It is friendly user software, which is used to record the train schedule timing information in

data files.

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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—

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.

8.5.2 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.

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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

8.5.3 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.

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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.

It is heaving the facility of according the calls on each port

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Chapter-9

RAILWAY NETWORK

9.1 INTRODUCTION

Indian railways has decided to set up their own Corporate Wide Information System (CWIS)

called RAILNET to provide computer connectivity b\w 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)...

The networks used railways are-:

1) Rail-net.

2) FOIS: - Freight operation and information system.

9.2 ORGANIZATION

1) First rail-net was established b\w Railway Board, 9 Zones, 6 Production units in

phase1.

2) Than extended to 6 new zones, 5 centralized training institutes, research &

development and standard organizations, metropolitan transport projects in phase 2.

3) The divisional officers, Zonal training institutes will be connected to rail net in phase

3 and finally to station, yards, shades etc….

9.3 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.

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9.4 TOOLS

1) E-Mail.

2) EDI (Electronic data interchange)

3) WWW

4) FTP (File Transform Protocol)

5) TCP (Transmission control protocol)

9.5 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 b\w Railway Board & Zonal

railway through our own “Intra Railway Network (RAILNET).

9.6 RAIL-NET GENERAL ARRANGEMENT

1) Procurement installation & Commissioning of server, Router, Switches, Modem etc…

2) Testing and Commissioning of DATA links.

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3) Loading and Configuration of system software.

4) Training of railway personnel as per contract agreement Zonal railways

5) Established their Local Area Network (LAN).

6) Arrange for data circuits on railway / dot hired channels.

7) Maintenance of rail net infrastructure as well as Web-Pages

9.7 HARDWARE COMPONETS

1) Servers.

2) Routers, Switches & Hubs.

3) Structured cabling using UTP-CAT 5 cabling

9.8 SOFTWARE COMPONENTS

1) MS Windows NT Server (Operating system for server)

2) MS Windows NT Work station 4.0 (Operating system for work station)

3) Internet information server 3.0 (Administrates internet access in LAN)

4) Front page express 98 (For designing of web pages)

5) Lotus nodes clients 4.6 (Provides E-mail facility to local users)

6) Cisco works with SNMPC (Administrate router)

7) Cisco fire wall (Provides safely to railway information)

8) NMS (Administrate FOIS)

9.9 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

37

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 than 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.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

Fig 8.1 Concert Network Topology

spreading over their jurisdiction. So any of the terminals access any of the train of Indian railway

originated from any of place

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CONCLUSION

In review this internship has been an excellent and rewarding experience. I have been able to

meet and network with so many people that I am sure will be able to help me with

opportunities in the future.

One main thing that I have learned through this internship is time management skills as well

as self-motivation. When I first started I did not think that I was going to be able to make

myself sit in an office for eight hours a day, five days a week. Once I realized what I had to

do I organized my day and work so that I was not overlapping or wasting my hours. I learned

that I needed to be organized and have questions ready for when it was the correct time to get

feedback. From this internship and time management I had to learn how to motivate myself

through being in the office for so many hours. I came up with various proposals and ideas

that the company is still looking into using.

I enjoy this line of work, but I am not sure if there is enough room to grow through this

company. I will continue to work hard in my position and hope to continue to learn about the

industry and meet new people. This was an excellent experience

39