Rail Report(1)

8/6/2019 Rail Report(1)

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ACKNOWLEDGEMENT

It is a pleasure to acknowledge my deep sense of gratitude to Mr. A. J. Ghosh, SeniorSection Engineer, Eastern Railway, Howrah, who directed and guided me with his timely advice

and constant inspiration, throughput the entire period of my training at the signal workshop,

Eastern Railway, Howrah , which thereby eased the task of completing this technical report.

I wish to reciprocate in full measure, the kindness shown by all the technicians and

controllers who guided us through the various intricacies of the railway system, and encourage

and inspired me in successfully completing this Technical Report.

I am also thankful to my college authority for having allowed me to undergo this training.

Finally, I must say that no height is ever achieved without some sacrifice made at some end and

it is here I own my special debt to my parents and finally members for showing their love andpatience throughout this entire period of time.


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STM:

STM is Synchronous Transport Module. STM is an electronic device which can convert optical

energy into electrical energy and vice versa. The system also gives us many numbers of 2mbps

frequency.

Such as: STM1=63 nos of 2mbps.

STM4=252 nos 2mbps.

STM16=1008 nos 2mbps.

STM1 is operated in -48V DC and it has different cards.

1) SYNCHRONOUS CARD: this card have many functions such as to measure Tx, Rx

power of fives for both sides and 63 nos of E1(2mbps) always communicate with the

NMS (Network Manage System) and in case of power loss of fiber or fault of 2mbps isthe system or transmission path, it gives us different alarms through front panel LED.

2) TEXTCARD: In case of any station for STM1,utilization of 2mbps is more than 21no.s,

then we have to use Text Card for other 42 nos of E1, physical connectivity in back

panel provided by the help of Text Card.

3) ADM: ADM is Add Drop Multiplication Card. Main function of the card is optical signal is

converted into electrical signal and vice versa. It also gives 63 nos of 2mbps for

utilization of electrical path.

4) PSU: Power Supply Unit Card. It works in -48V DC and convert it into +5,-5V separately.

Inner portion is protected for short circuit and overload. The card works on -43V DC to -

60V DC. It has two nos of LED in front panel, one is green, another is red.

5) OLI: OLI is Optical Line Interface Card. In case of tri-junction fibre station. OLI card gives

us two nos of post, one for Rx another for Tx and then by the help of NMS we can

connect the fiber through line fiber.

In normal condition,STM1 gives us 21no.s of 2mbps electrical path for the

connecting of multiplication system and rest of E1(42) are looped from A path to B for

nearest SPM station transmit.

6) PigTail:pig tail is one type of connection which has two legs, one leg is connectedwith a connector and one leg is open. Open leg is spliced by the help of splitzer machine

for permanent OFC joint.

7) Patch Card:patch card is one type of connector which has two legs and both are

Molded with a connector and length of the Card is 5meter above with the help of Patch

Card. We connect the ADM Cards port (A&B) with a 0dbm metal connected to Pig Tail.


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8) DDF: DDF is 2mb distribution box. In front panel we connect 21 nos of E1(2mbps)

number wise. Left side Rx of E1 is right side Tx of E1. Similarly if it is maintained up to 21

nos in every E1, have two nos of v link connector (Rx, Tx) for E1 testing in STM side and

Multiplexing side.

MULTIPLEXER UNIT:Multiplexer is an electronic device which can convert 2mbps

into 32 time slots and each time slot gives us one channel for utilization of subscriber

end such as telephone, computer, exchange etc. the Multiplexer unit has an input of -

48V DC with respect to a charger and 400AH battery backup for beakless

communication, in case of any type of power failure. Different types of cards used in

Multiplexer Unit are described below:-

1) PSU:PSU is Power Supply Unit Card. It is a DC-DC converter. It has four differentoutput voltages, such as +5V, +10V, -10V, +80V and ground. The card has to heavytolerance of -43V DC to-60v DC voltage. Protection for over current and voltage are

given to the card.

2) NIM:NIM is Network Interface Module. We can operate this NIM card in fourdifferent ways. Using this we can set dual address. Master and slave mode can be

selected using dip switch, with the help of NMS we programme the all 30 nos of

channels for multiplexer utilization of such station and we download the programme

to NIM Card permanent operation of that station. LEDs in the front panel indicates

us the health of both sides E1. The Card also gives us local failure alarm and remote

failure alarm.

3) Tribu teryCard: This card converts 2mbps to time slots and vice versa usingmultiplexing and demultiplexing. This card can be operated in D.I. mode as on End

Terminal(ET) mode by dip switch. Tributery card also generate two E1 is its internal

work and we can bypass digital or loop by the NMS.

PSU,NIM and TRIB are called Primary Cards. The multiplexer gives us 32 nos of

time slots of 2mbps frequency. Among these 0 no. time slot is used for

synchronization, 16 no. time slots is used for signaling command for all time slots

and other time slots are used in subscriber end.

4) Voice Card: we can operate the Voice Card in 2w mode & 4w mode by the help ofsetting of jumper in module card. 2w mode has 4nos of conductors. Two of

conductors are used for signaling. For signaling mode E &M lead is used, E lead for

Ear and M lead for Mouth. For 4w mode, two conductors are used for Rx and two

conductors are used for Tx AND signaling mode is operated by voice

frequency(DTMF).


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5) Exchange:for connectivity of local exchanges the card is provided for localcommunication by exchange.

6) Hot Line:Hot Line is to communicate end to end without dialing arrangement.Both side telephone is operated by the help of off hook and on hook. The Hot Line is

mainly for VVIP . It is more safe than other dialing phones.7) Data:Two type of Data Cards are used pair which are low speed data and high

speed Data Card. Low speed Data Card has a speed of 12kbps and high speed Data

Card has a speed of 64kbps. It works for computer data and PRS( Passenger

Reservation System), and data larger for UTS(Un-reserve Ticket System).

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Rail Report(1)