Four wire multi-satellite intrusion alarm with multiplex annunciation

摘要: An intrusion alarm system has a number of satellites each connected to master by an unshielded cable having only four conductors, namely two power drive signal conductor which supplies the satellite transmitter and control circuit, conductor. When is detected satellite, its circuit transmits high level on also sets latch in satellite. The rocker switch investigator turns off when he arrives at supervised premises. This causes counter send set interrupting counting pulses Each counts if that satellite's been sends pulse back immediately after count associated with counter. received are recorded register then displayed show status satellites. A tamper operates tampered latch, so off, switches can be annunciated. test transceiver own receiver provided