Fronius GEN24 Modbus Control - how to get it working?

[Willem59]

I hope somebody can help me with this:

After installing this app on my Homey Pro 2023 I get no data and error:
“Modbus polling failed”.

I own a Fronius GEN24 12 inverter with 15.8 Reserva battery from Fronius.

I used the internal (static) ip-adres of my inverter.
I enabled the api
I made Fronius a TCP server for Modbus
Other values:
TCP port 502
Unit 1 (though i am not certain where to find this)
Poll interval: 10

What can I do to get it working?
Thanks, Willem

[Peter_Kawa]

First of all which Fronius app, Willem?

Probably it’s this one:

Fronius GEN24 Modbus Control | Homey

but there’s no forum topic or active support by the developer.

[Willem59]

Yes Peter,
That is the one.
No support, I saw that.

But, I was hoping some user could help me with it.

I would like to control my Inverter and battery with advanced flows in Homey.
With the other apps I do not get ‘and-’ and ‘then-’ cards.
I could miss something (which has happened before)
Thanks, Willem

[Peter_Kawa]

Hi Willem,

Perhaps Ronny can show you some possibilities?
He uses his Modbus app to control stuff

Homevolt battery from Tibber in Homey?

We are getting a lot offtopic. But last one…I use my Modbus app to control the Fronius Gen24. To set charging/discharging limit, you have to set 2 or 3 registers and one of them bitwise (as int). Modbus is not the best standard for integration. Perhaps Matter offers more possibilities in future if manufactures will add it to their existing products.

The Solaredge + Growatt TCP Modbus app might do the job as well (it’s not limited to these 2 brands):

[APP][Pro] SolarEdge + Growatt TCP modbus

Purpose The difference of this app and the already existing solar panels app is that this app reads the data directly from the inverter. The solaredge api and others are mostly limited to 300 calls/ day, so you get only updates every 10-15 minutes. The modbus app receives data every few seconds. If you have the Solaredge energy monitor installed you can maximize your self-consumption and limit your exported power by using it. You can make flows based on your generated solar power, exported p…

[Edwin_Biemond]

fronius is not so hard and Ronny has 1 I think and uses his app to control it

had many request for this but no 1 can provide me some vpn access , mostly in a few hours I have a working one. controlling requires more testing.

you can also do it yourself , not so hard and code is on github. any help is appreciated.

[Willem59]

Thanks for the tip guys!
I will dive in. Experience learns that this kind of things often are very difficult for me. But who knows, maybe I’ll surprise myself.

[RonnyW]

The local Fronius API (REST API used by the other apps) is readonly access. It can only read realtime data.

In addition there is a Solarweb cloid API to get additional data.

I’m using the HomeAssistant Integration, because it combines both. Then I just import the data to Homey via HA community app.

I made and use the Modbus TCP app to control some special settings for my Gen24. You don’t have many possibilities, that’s why I just used basic Modbus instead of implementing an app.

I use Modbus for:

• limit battety usage while car charging from grid
• force battery charging from grid (winter at night based on price)
• you can set minimum battery level
• but not so much more.

See details if you want to try:

[APP][Pro] Modbus - Connect every Modbus devices

Modbus A small tool to add every Modus/TCP device to Homey [HomeyPro_Modbus_AppLogo] This tool allows to add any Modbus/TCP device to Homey without a specific app. You can read and write Modbus register with flows. How to start? Add a device. Insert the Modbus details of your device including IP address, port and Modbus device ID. [HomeyPro_Modbus_AddDevice02] [HomeyPro_Modbus_AddDevice03] The Homey device doesn’t offer functionality. It only connects to your Modbus device. How to…

Check the examples on my blog

Modbus – Ronny Winkler

Modbus: Anwendungsbeispiel – Ronny Winkler

[Edwin_Biemond]

nowadays with chatgpt codex and these homey, HA github repos from me and others plus have the right modbus registers pdf , it should be easy to add new driver to the apps. or make a new 1 from scratch.

really impressive

[Willem59]

Thanks Ronny,
Appreciate this.
I will look int it when I find some time for it.

I am very careful about this. My knowledge of mod-bus-stuff is zero.
My wife is quite ‘specific’ about taking risks with meddling with essential installations.
Spouse-acceptance’ for Homey is high, and I would’t want to risk that ;-).

I chose Fronius not only for the quality, but also because there were Homey-apps for it: not realising the limitations, so I am a bit disappointed about that.

But, again, thanks for your tips and I may dare to try it.

[Willem59]

Maybe someone has a tip.
In the Fronius GEN24 Modbus Control app I get an error (Modbus polling failed) and it loses connection..
After restarting the inverter, Homey and restarting the app itself, it comes online for maybe a minute or so.
When I restart the app after that, it workes again for a shhort time.

In the time it works, I have acces to ‘and’ and ‘then’ cards.
This app seems to do what I want (as long as the connection fails again).
Could this be some generic failure that could be related to some Modbus setting or some timeoutsetting in de Homey-Fronius Gen24-app or something like that?

It is a long-shot, I know…