Alarm with central control station - uses channel with interrogation signals incorporating address and instruction for checking state of individual

摘要

The alarm system uses a central control station which can establish the state of the individual alarm transmitters. There is a simple and surveyable link between the control station and the alarm transmitters to provide a high reliability and faultless inspection of the system. The control station (1) is linked to the alarm transmitters (3) via a collective channel (2). The control station transmits a sequence of different interrogation signals along the channel. Each signal consists of an address section and an instruction section. The signals are compared in the alarm transmitters with allocated address codes. An answering signal is transmitted via a logic system along the channel and displayed in the central control room.