Security system having detector sensing and identification

Abstract

A security system including a plurality of sensor loops, each having a plurality of detectors and associated detector identification devices which upon actuation produce analog detector signals of different amplitude for each detector in such loop to identify the actuated detector. The sensor loops each have a common loop output which is connected to a different one of a plurality of input terminals of an analog to digital converter and multiplexer circuit which includes a multiplexer switching circuit for selectively switching between such inputs and which converts the selected analog detector signal to a digital detector output signal. The outputs of the analog to digital converter are connected to a digital data processor circuit, such as a microprocessor computer, for processing the digital detector signals to determine which detector produced such signals and to generate a corresponding output signal that may operate an alarm means such as a bell or indicator light. The sensor loops each include a plurality of detectors which may be detector switches that are connected in series or in parallel sensor circuits, such sensor circuits each including an identification device for identifying its associated detector when such detector is actuated. The identification devices can be resistors each of a different value for its associated detector, or it can be constant current sources or constant voltage sources of different values.

Dependencies are inferred from the claim text.