VESDA Metal Box HLI - Modbus Type 2

The role recommended for a VESDA HLI is secondary monitoring, and primary reporting to a fire panel, or to a different primary reporting system, is also suitable; taken on for primary reporting, the interface must be integrated with, and approved or listed with, the panel or system it serves, to whatever fire standards and codes are in force.

Wall-mounted and with its echoing function disabled, VHX-1410 is the Type 2 build of the VESDA Wall-mounted ModBus High Level Interface. Any host that speaks the ModBus protocol reaches a VESDAnet through it.

Addressing carves the range into 7 logical networks, network 1 taking the first 30 addresses, network 2 the addresses between 31 to 60, and so on.

Every VESDAnet fault lands on one or more Modbus HLI faults: Head Fault on its own, Head Fault qualified as Battery and Mains or as Scanner, and Flow Fault. A fault treated as a network fault reaches all zones, while a zone fault stays on the zone it belongs to. The host can read Detector Alarm State - Alert, Action, Fire - along with Smoke Level, Smoke Bargraph Level and the detector alarm thresholds, and can issue the Reset Detector and Isolate Detector commands as well as Start Scan Test. A VESDA HLI is recommended to work in secondary monitoring; primary reporting is also suitable, but only where the interface has been integrated and approved or listed with the panel or reporting system that receives it, against the fire standards and codes that apply.