Looking for a alternative for Modbus with SMA Converter

Homer-Sim · October 7, 2025, 12:26pm

Hello,
my converter is not providing modbus data anymore (maybe broken - no guaranty anymore)
I tried a lot to make it working again but without success.
Now I found ha-pysmaplus but this is quite focused on HA.

Do we have a way to integrate HA Addons or what ever it is into OH?

Thanks

mstormi · October 7, 2025, 12:43pm

No.
But if your hardware is broken, you cannot access it anyway so you have to either replace it (which has become as cheap as 10 € for a Modbus/(W)LAN device) or look for an entirely different approach. Which you have given absolutely not enough information for to attempt.

Homer-Sim · October 7, 2025, 12:52pm

The “funny”thing is, SMA Sunnyportal is still receiving the data.
So the converter is still working and probably sending data to the homepage of SMA but not longer via Modbus.

What information can I provide you to get help?

Baschtlwaschtl · October 7, 2025, 3:30pm

Did you restart the modbus interface from the inverter?

Homer-Sim · October 7, 2025, 5:39pm

I did shut down the complete converter. Is there somewhere a restarter only for modbus?
Or do you mean in the sunny explorer turning on/off the module? That I did too. But it helped only the first time.

splatch · October 7, 2025, 5:59pm

I had a look on the library and it seems to call inverter (?) using its HTTP interface to fetch data in JSON format. Whole logic is here: https://github.com/kellerza/pysma/blob/master/pysma/\__init_\_.py . This is also library used underneath by ha-pysmaplus, hence you can give it a try and see if you will be able to fetch readings in python and i.e push updates over OH HTTP interface.

There was an attempt to make OH-HA integration, a while ago, but from what I remember many folks simply setup mqtt in between.

Baschtlwaschtl · October 7, 2025, 6:03pm

I have a sma tripower inverter. There is a option to activate/deactivate the modbus connection.

Device config, communication setting.

There is option for Ethernet, wifi and modbus.

Try deactivate, save, activate, save.

Greets

Homer-Sim · October 7, 2025, 6:05pm

Thanks for your support.
In the meanwhile I found a different one which seems to be able to fetch speedwire data.

github.com/littleyoda/ha-pysmaplus

custom_components/pysmaplus/init.py

main

"""The sma integration."""

from __future__ import annotations

from datetime import timedelta
import logging
from typing import TYPE_CHECKING, Any
import pysmaplus as pysma
from pysmaplus import Device
from homeassistant.components import network

from homeassistant.config_entries import ConfigEntry
from homeassistant.const import (
    CONF_HOST,
    CONF_PASSWORD,
    CONF_SCAN_INTERVAL,
    CONF_SSL,
    CONF_VERIFY_SSL,
    EVENT_HOMEASSISTANT_STOP,
)

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My inverter has a webconnect in settings but no webpage is displayed if I put that on true.

Homer-Sim · October 7, 2025, 6:08pm

Yes, that is what I did. And as explained. The first time it worked and the other day not anymore.

Which firmware version does your inverter has?
Mine:

Homer-Sim · October 7, 2025, 6:10pm

The inverter logs show some update entries …
Maybe SMA “killed” modbus module?

Baschtlwaschtl · October 7, 2025, 6:13pm

My firmware is different. 3.6.18.R

different inverter..

maybe ask in the photovoltaik forum..

My webconnect is deactivated..

Homer-Sim · October 7, 2025, 6:13pm

My grafana graph is showing the problems quite good:

Baschtlwaschtl · October 7, 2025, 6:15pm

This looks weird..

Ethernet or wifi? Maybe here a bad connection?

Baschtlwaschtl · October 7, 2025, 6:16pm

Did you tried a different modbus programm.. Some different Linux or windows programm

For testing I tried modpoll for Linux

Homer-Sim · October 7, 2025, 6:23pm

ethernet

Homer-Sim · October 7, 2025, 6:26pm

I tried docker run --rm oitc/modbus-client:latest

same result

Baschtlwaschtl · October 7, 2025, 6:29pm

Hmm, then I can’t help you.

Try photovoltaik forum or sma service or your PV-installer

Good luck

Homer-Sim · October 8, 2025, 4:17pm

For all who will stumble about this threat or the same issues. I managed it now with a python script.
Based on this HA approach: