FIELD: guarding fences of objects, detection of intruders into monitored region and monitoring movement of objects (cars). SUBSTANCE: device provides optical connection loops which provide two-beam fence by embracing each side of perimeter and providing joined optical connection loop which input is current amplifier of master oscillator and output is photodetector which is connected to signal processing unit. Infrared fence is provided by retransmission of primary pulse signal through optical connection loops. Primary pulse of master oscillator is converted to sequence of pulses due to different time delay of elements of transmitters and signal passage in air. Each pulse of this sequence describe passage of primary pulse through optical connection loop which covers respective fence. When intruder breaks side of fence, number of pulses received by signal processing unit alters. This results in generation of code for detection of corresponding side of fence by means of signal processing unit using AND, NOT and delay gates. This results in output of alarm signal. EFFECT: increased reliability, decreased cost for manufacturing and usage. 2 dwg
