ijeamaka-omayeka avatar image
ijeamaka-omayeka asked

Victron integration with home assistant using Modbus TCP

I'm currently trying to integrate my victron setup into home assistant, but when I turn on the Modbus on my CCGX I keep getting the message:

ERROR "Error processing function code 3, unit id 126, start address 40000, quantity 2, src Modbus address 40000 is not registered"

My setup is a MG50 with fronius 8kw, victron mppt 250/100, 10kva Quattro, 13.8kwh BYD LiFePO4 battery, CCGX with firmware version v2.73.

Please any idea on how to resolve this?

Modbus TCP
2 |3000

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1 Answer
shaneyake avatar image
shaneyake answered ·

Can you post what registers you are trying to read into Home Assistant?

40000 register is also not valid. Last Victron register is currently 3826.
Some modbus TCP clients will send the function code as the 4 and the registers afterwards as 0000 but there is no register 0 on a GX, starts at 3.

Likely the unit id is also incorrect. In the modbus TCP menu, services will show you the correct id for the diffrent Victron Components.

2 |3000

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Thanks for the response.


BMV: 225

PV inverter: 20

MPPT: 247

Quattro: 246

System: 100



817, 823, 808, 840, 814, 842, 850


226, 303


776, 777, 789, 791, 784, 785, 786, 787

PV inverter:

1027, 1028, 1029, 1046, 1052

I was already seeing the error message even before inputting the Modbus configuration in home assistant.

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That looks all correct to me.

You can clear the error and try find out what on to trying to access Modbus.

Does your HA integration work? If that IP is for your HA setup, then possible something misconfigured.

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That's the IP for my CCGX
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