SECURITY ALARM DEVICE Russian patent published in 1997 - IPC

FIELD: security devices, in particular, autonomous systems which prevents unauthorized access to monitored areas. SUBSTANCE: device has synchronization oscillator, communication line, N detectors, two commutators, pulse generator, AND gate, flip-flop, indicator. Two filters, mode switch, reset button, five pulse generators, decoder, generator, AND gate and N second flip-flops are introduced to accomplish the goal of invention. Two filters, two commutators, detector, reset button, sixth pulse generators, two AND gates, counter, decoder, first and N second flip-flops and indicator are located in user board which is comprised in device N. This results in possibility to design closed self-tested structure which user boards are located on monitored check points and generate alarm signal when unauthorized access is detected and when similar alarm signals are receive from other user boards. EFFECT: increased level of autonomous operations, increased reliability. 2 dwg