Abstract: A bidirectional electronic interface couples remote sensing security transducers such as fire and burglar monitoring devices to a computer such that the circuitry of the bidirectional electronic interface functions to both transmit signals from the remote sensing transducer to the computer for analysis and processing and transmit control and data information to remote control and monitoring stations. The computer scans the content of the bidirectional electronic interface for remote transducer information with the bidirectional electronic interface serving as a storage apparatus. The computer is programmed to respond to the information presented by the bidirectional electronic interface to initiate predetermined control and data recording functions for both direct activation of remote apparatus and for transmittal of control signals through the bidirectional electronic interface circuitry to remote apparatus.

Abstract: Tamper test signals of varying magnitude and polarity are randomly applied to electronic sensing circuits to determine integrity of the sensing circuits. A monitoring circuit measures the response of the sensing circuit to the applied tamper test signals and responds to deviations from predetermined information indicative of sensing circuit integrity by generating output signals suitable for control or alarm purposes.