VESDA Modbus HLI for Darwish & Honeywell only

Secondary monitoring is the recommended role; primary reporting to the fire panel or another primary reporting system is also suitable. Where primary reporting is the duty, the interface must first be integrated, then approved or listed with the serving fire panel or primary reporting system, under the relevant fire standards and codes.

VHX-0410 is the ModBus HLI - Type 2 within the Xtralis VESDA ModBus HLI family, and it is the variant which has the echoing function disabled. Quiescent power consumption is 1.68 W.

Smoke Level is reported relative to the Fire Alarm threshold where the full scale is 20, giving actual smoke level = (Reported smoke value * Fire1 Threshold) / 20. The Fire Alarm threshold itself is reported as the relative sensitivity to 1 %obs/m, so a detector set at 2 %obs/m reports 50, one at 1 %obs/m reports 100, one at 0.1 %obs/m reports 1000 and one at 0.02 %obs/m reports 5000.

All VESDAnet faults are mapped on one or more of the Modbus HLI faults, namely Head Fault, Head Fault (Battery and Mains), Head Fault (Scanner) and Flow Fault. Faults categorised as network faults are mapped onto all zones, whereas zone faults are mapped onto that particular zone. Information reaching the host takes in Fault Status (Head, Battery and Mains, Flow, Scanner), Detector Alarm State (Alert, Action, Fire), Smoke Level and Smoke Bargraph Level. Secondary monitoring is what a VESDA HLI is recommended for, taking in fire alarms as well as the other notifications a VESDAnet carries; used instead for primary reporting, it must be integrated and approved or listed with whichever fire panel or primary reporting system receives it, to the relevant fire standards and codes.