scope:

Modern signalling installations typically provide the signalman with a mimic panel showing, by means of coloured lights, the state of all the signals and points, and by means of displays the location of trains currently under the control of the signal box.

A push button control desk enables the points and signals to be operated and is also equipped with facilities for communication with various other people, for monitoring specific places such as level crossings and to control the operation of any other systems provided to assist with traffic regulation.

To assist the signalman in correctly identifying a train and then making the appropriate judgements with regard to routing and priority each train is allocated a train number or train description.