Controlling Belimo Valves

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PIC EU SR24A-MOD 4C-product.jpg

Belimo valves are one of the most recognised and widely used makes of valve in the HVAC industry.

The libraries on this page provide the tools to control and monitor valves using the MQTT open controls protocol and Node-RED.


Modbus Registers

Note that the register number is one more than address.

Operation Registers

Belimo modbus1.png

Service Registers

Belimo modbus2.png

Example Commands

Read Setpoint

As an example, to read the Setpoint requires sending a FC3 read command (03) to the device (01 default) calling for register 1 (00 00), requesting a single value (01), ending with the CRC (Cyclic Redundancy Check).

In modbus the following characters would be sent to the valve over RS485:

03 01 00 00 01

Close Valve

06 01 00 00

Open Valve

CRC Calculation

Analogue Control