Train Describer.

11. TRAIN DESCRIBER INTROUDUCTION The train describer is basically a data acquisition system, with the data being collected via inputs from the signalling system. The train description is a four character code which is made up of a digit for the train class, a character for the train’s destination and a two digit train number.

Equipment In electro mechanical, the block bell system is communication system between signal boxes . A development of equipment was simply replace the relays with logic gates of TTL or CMOS in electronic logic system.

Computer system Computer system consist of one or more processor,fixed memory(EPROM),dynamic memory (RAM),input device (KEYBORD,MOUSE), etc output devices(MONITORS,PRINTERS etc)

Operators’ control unit The signaller can enter the train description into the system via an operator ’control unit (OCU). An OCU consist of a monitor, a keyboard and character genrator, now usually in form of a Personal computer. The signaller has access to the system via a keyboard. He can;    

insert or ‘interpose’ train descriptions at most berth under his control. cancel descriptions. enter the time into the clock berth(S) search for the location of the train.

INTERLOCKING input for the stepping of the description to the TD system comes from the interlocking. Interlocking may be relay type or solid state interlocking.

DISPLAY The TD (train describer) display may be CRT (cathode ray tube) or LED (light emitting diode) .There may be also third type which is VDU (visual display unit) which can be placed alongside a panel.

PRINTERS Printers Can Be Used Dot Matrix or laser types.dot matrix are easy to run and cheap in cost.

AUTOMATIC TRAIN REPORTING (ATR) Records certain movements of trains in specified area and used for further analysis when required.

TRUST (Train Reporting Under System Tops).It is a form of ATR with wider distribution facilities.

FRINGE Box TD fringe box TDs are placed where small box is away from the main box and needs some and train info. For the area it covers.

Adjacent box TD The main TD must be able to communicate with adjacent main boxes to transmit and receive train descriptions to and from them as the train passes from one controlled area to another.

BLOCK SCHEMATIC DIAGRAMS Block schematic diagram are used to show the stepping and facilities required to be carried out by TD.the berth and TD are shown on the schematic diagram and a number of different types of berth and steps are used depending on the situation.

BERTH TYPES Berths come in different types and can have different characterstics.berths can be either a ‘FROM’ or ‘TO’ berth,depending on the direction of travel.    

Normal Berth-the berth displyed on VDU showing the train code. Blind Berth-berth used as a store but not displyed on VDU. Route Berth-used to display ‘route set’ information. Clock Berth-used to display the time of the day.

STEPPING FUNCTIONS Different types of stepping function are    

Normal Step-the description steps FROM one berth to another berth as the train moves. Copy Step-description copied From one TO another without clear out TO berth has special condition. Hold Step- description copied From one TO another without clear out FROM,but clear out berth has special conditions. Link Step-the train description is From one berth TO another berth whenever The TO berth is occupied.

Sushil Kumar(DET) 13/08/2015