Programmable telephone signaling device is a universal device, which makes possible - except for the standard telephone and emergency-dispatcher's communication - carrying out of many other additional functions. It is used for announcing alarm signals, as well as verbal and acoustic messages sent over the intrinsically safe telephone line or previously recorded and stored in the inside memory, and for listening watch of the signaling device surrounding. They also can be used to call the dispatcher by the use of buttons ALARM and DYSP, in the alarm and regular modes. The switching of functions of broadcasting and listening enables to carry out a simplex conversation with persons who are in close vicinity of the signaling device. After picking up the microtelephone PST it performs telephone functions. Moreover, the signaling devices enable the remote control - over the intrinsically safe telephone line - of four output circuits and receiving information on the condition of devices which may be connected to four two-stage inputs. The telephone signaling devices PST cooperating with LPI units, have been designed to operate in methane areas (I explosion group, M1 category) and in zones of explosion hazard of manufacturing rooms of chemical plants, warehouses, fuel pumping stations and other facilities in danger of explosion, gases, flammable liquids vapors, and dusts classified in II group of explosion, categories 1 and 2 and temperature class T3.

With any automatic telephone exchange with tone dialing (DTMF) by the intermediary of separation line units LPI or LPN.

Central from the line separation units LPI or LPN