An EVCS is a fixed, secure, bi-directional, full-duplex voice communication system to assist firefighters in an emergency in high rise buildings or large sites where radio communication may not work, and covers the operation of fire telephones, disabled refuge systems, and the Disabled Toilet Alarm.

The VoCALL Compact Emergency Voice Communications System (EVCS) is designed to fully comply with BS5839-Part 9:2011 (abb. Pt9) for use as a fire telephone system, disabled refuge call system or as a combined system when both fire telephones and disabled refuge points are required.