Special telephone system with release of untriggered functional units via an information channel transmitting speech signals

摘要

The invention relates to a special telephone system having a central station equipped with at least one operating device and one or more substations, which are likewise provided with operating devices, are connected to a central station via information channels transmitting speech and control signals, and whose operator's circuit, which is allocated in each case to an operating device, is connected to a connection plane of an allocation device of the respective station, and whose other connection plane is connected to transmission devices. The alternating current release signal transmitted from the central station (ZT) via the speech channel is converted in the respective substations (US1 to n) by means of the signal converting device (SU) into the direct current turn-off pulse and used to release functional units (FE...). Such special telephone systems are used, inter alia, as operating systems for operational monitoring in transport and power supply companies. <IMAGE>