Can a custom Cerbo GX Node-RED Virtual Switch be read via Modbus TCP?

Hi, I’m using Cerbo GX with Modbus TCP and Node-RED, and I’m trying to find out whether a Virtual Switch created in Node-RED can be read through Modbus TCP.

The switch is created directly in Node-RED on the Cerbo GX, and it is correctly displayed in the GX Touch UI.

Relay control works fine for me, for example using register 807 for the CCGX Relay 2 state. However, I cannot find any Modbus TCP register for the custom Node-RED Virtual Switch itself.

Is there a way to read the Node-RED Virtual Switch through:

  • a Modbus TCP register?

  • a D-Bus path mapped into Modbus TCP?

  • or using another supported method inside Venus OS?

My setup:

  • Cerbo GX with Venus OS Large v3.72

  • Node-RED running directly on Cerbo GX

  • Home Assistant with a Node-RED flow reading Modbus TCP data

  • Modbus TCP enabled on Cerbo GX

  • com.victronenergy.system on Unit ID 100

The goal is to get the state of the Virtual Switch into Home Assistant and also be able to control it.

Below the question is also a picture of my Node-RED flow running on Cerbo GX where you can see the orange node named “Automatické ovládání bazénu” is the Virtual Switch I want to read via Modbus TCP.

Thanks.