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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.

Power supply

Central from the line separation units LPI or LPN.


PSTintrinsically safe, without display
PST-Wintrinsically safe, with display
PST-Rdesigned for immediate call of fire brigade, police etc. with single button
PST-Tdesigned for cooperation with loudspeaking communication systems

PST technical data

MarkingI M1 Ex ia I or II 2G Ex ia IIB T4
Power supplycentral from intrinsically safe separation units LPI
Calling unit supplyfrom intrinsically safe battery 0.7Ah/12V
Nominal signal level0 dBm
DialingPM / DTMF
Permissible voltage at the two-stage outputmax.24V
Permissible current at the two-stage outputmax. 50mA
Coefficient of anti local effectmin. 16 dB
Permissible surroundings noisemax. 80dB
Loudness of signal sound (from 1m distance)min. 90 dB
Minimum operating time at messages broadcasting2h
Subscriber's connection attenuationmax. 12dB
Optical calling signalvisible from long distance
Casing protection levelIP65
Dimensions520x253x110 mm
Weightca. 5 kg
Operating temperature rangefrom -40 to +40 ° C