Fail safe signal transmission system - comprises three wire transmission between combinations to protect against short circuits etc.

摘要

A fail-safe system for the transmission of signals between a sender station and a receiver station in railway communication systems is provided by logical combination of relay states. In particular the system offers safeguard against cable short circuits and disturbance voltage peaks. A sender station operates to communicate information to a receiver station e.g. switching box to warning lights. Three line signal transmission occurs to control the state of a main relay. Signals may be initiated on a number of input relays. Auxiliary relays operate in logical combustion with receiver auxiliaries to ensure that the output relay is switched correctly in the event of a failure.