Unable to read Modbus Values from Huawei Wallbox

1

Installation OpenHab 5.1 on a Raspberry Pi 4

Im using a HUAWEI SUN2000-8KTL-M1 and added a Huawei Wallbox to my system.
It is displayed in the Fusion solar App and it`s working.
I added my Inverter to Openhab reading the values with modbus a year ago.
It works fine.
So I tried to add my wallbox also to Openhab
I got the registers from here https://github.com/evcc-io/evcc/discussions/10262
The value I need is Total Output Power (register 4108)
So I tried to add a Modbus Poller to my system and a data Modbus Reader
But after a view seconds I get an Error

21:02:26.583 [ERROR] [ort.modbus.internal.ModbusManagerImpl] - Last try 3 failed when executing request (ModbusReadRequestBlueprint [slaveId=1, functionCode=READ_MULTIPLE_REGISTERS, start=4108, length=2, maxTries=3]). Aborting. Error was: net.wimpi.modbus.ModbusSlaveException Error Code = 2 [operation ID 8bba1d76-f4bd-4522-a4eb-977b85f66c47]

I donĀ“t know hot to fix ist.

2

Modbus Error 2 means ā€œwrong address or register spaceā€. While register 4108 seems correct, are you connecting to the Inverter or the Wallbox? Iā€™d think you need a new Modbus thing (bridge) to connect to the Wallbox for the Poller and Data things.

3

I contacted the Huawei support.
Iā€™m connected to the converter whitch is correct.
There is no possibility to connect to the wallbox.
Maybe these registers are only available if the car is connected to load.
Iā€™m waiting, but the car isnā€™t delivered until now:-(

4

Hi,

ok, I see - understand now the Inverter is feeding through the Modbus registers from the connected devices.

You may check out the register file here: huawei-solar-lib/src/huawei_solar/registers.py at v2 Ā· wlcrs/huawei-solar-lib Ā· GitHub

There is a section for the SCharger registers like this - maybe that works?

SCHARGER_REGISTERS = {
    rn.CHARGER_SOFTWARE_VERSION: StringRegister(30031, 16, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_ESN: StringRegister(30015, 16, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_MODEL: StringRegister(30078, 14, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_RATED_POWER: U32Register("kW", 10, 30076, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_PHASE_A_VOLTAGE_SENSOR: U32Register("V", 10, 30500, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_PHASE_B_VOLTAGE_SENSOR: U32Register("V", 10, 30502, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_PHASE_C_VOLTAGE_SENSOR: U32Register("V", 10, 30504, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_TOTAL_ENERGY_CHARGED_SENSOR: U32Register("kWh", 1000, 30506, target_device=TargetDevice.SCHARGER),
    rn.CHARGER_TEMPERATURE_SENSOR: I32Register("Ā°C", 10, 30508, target_device=TargetDevice.SCHARGER),
}

Good luck!

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