Device for controlling a signal box

摘要

In the control of signal boxes (Stw) via operator stations (B1 to Bm) provision is made for specific commands (FB) to be separately enabled by the respective operator before they are issued to the key relays (G1 to G36) of the signal box. In order to ensure this, the key relays which are involved cannot be connected directly but rather only via series relays (GT1 to GT36). These series relays are a component of a test and logical connection circuit designed using relay technology. In said circuit, on the one hand the command entered is tested for plausibility and on the other hand dependency is provided between the operator station (e.g. B1) from which the operating action requiring enabling was performed and the enabling switching means (KF1) of this operator station. The testing and logical connection circuit is provided in common for all the operator stations. It ensures that no command which bypasses the signal box safety system can be effected without the involvement of an operator. <IMAGE>