The VESDA Modbus Type 3 High Level Interface (HLI) integrates VESDAnet1 network with host monitoring platforms such as Building Management Systems (BMSs) and Fire Alarm Control Panels (FACPs).

The Modbus Type 3 HLI acts as a proxy for all VESDA devices on the VESDAnet network, providing access to the rich status information that is available from VESDA detectors as well as the ability to control and configure these devices. Alarms are reported to the host within a few seconds of a detector reaching an alarm condition. Exact performance is dependent on the polling strategy and size of the monitored network. The Modbus Type 3 HLI is able to support up to 100 VESDA detectors on a single VESDAnet network.

VHX-0420 Modbus Type 3 HL

A standard unit used to provide a flexible solution where permanent mounting is not required. In this case a VESDAnet socket interface is required to connect the HLI onto the VESDAnet network.

The VESDA zone equates to the Modbus address field and allows the host to retrieve the overall status of the VESDAnet network as well as performing certain VESDA device configuration updates. The host is able to monitor and control VESDA devices on the VESDAnet network by reading and writing into registers in the Modbus map.