SP Telephone System

Signal Post Telephone Systems

Calling: When the train driver presses the CALL button below his SPT, the SMC will begin to ring, alerting the station master. Simultaneously, the SMC will send back a tone to the SPT, assuring the driver that ringing is taking place at the other end.

Similarly, if the CALL button on the SMC is pressed, a loud tone radiates from the SPT.

Speech: A press-to-talk or PTT button is provided on the SMC. With this control the station master can talk to or listen to the driver. The driver has no control. He can walk away after conversation with out operating any switch or control.

Monitoring: If this SMC is left in the ON conditions, the station master can listen to sounds from the vicinity of the SPT. Movement of trains, personnel and attacks by vandals can easily be identified.

Technical Specifications