Non-home run zoning system

Abstract

Zone indication is provided for a facility monitoring and control system by providing the system's sensors and control unit with counters which are simultaneously incremented with clock pulses delivered to the sensors via the multi-wire interconnect cable from the system's control unit. Each sensor output circuit has enabling circuitry connected, as with jumper pins, to a counter output corresponding to a predetermined number or count, and this number or count identifies the sensor. In one embodiment, each sensor output is enabled only during the occurrence of the corresponding count or number from its counter as the counters are incremented through their cycle. When the sensors are used to sense alarm conditions, the sensor sending an alarm signal is identified when an alarm condition signal exists simultaneously with a particular count from the counter at the control unit, with the particular count indicating which sensor is sending the alarm signal. When zone indication is utilized in conjunction with remote data gathering, data is transmitted between counter clock pulses. Should transmission of complex data be required, the counter clock pulses are inhibited and complex data is then read out from the sensor actuated when the counter clock pulses are inhibited, with the complex data read out at a rate governed by a different type of pulsed signal transmitted to the sensor. In one embodiment, zone indication signals are made compatible with sensor control signals so as to establish compatibility with previously installed in-place systems. This greatly facilitates retrofitting existing systems with non-home-run zoning.