Power supply 220Vdc, up to max 48 detectors connected in RS-485 serial loop with Modbus RTU protocol, with 20×2 display, alarm, fault and ON signal LED, n. 2 opto isolated digital inputs for any emergency button, n. 6 relay outputs 2 of which default set ( n.1 relays for siren output + n.1 relay for general fault signal) and 4 programmable, to activate alarm devices. Gas type, full scale, Warning and Alarm levels, relays association completely programmable protected by password, event log on the display. Automatic acknowledgement of connected detectors calibration with temporary inibition of the alarms. Also available open frame version for DIN bar mounting.