Fronius PV Inverter with grid meter

English Forum
1

I have a fronius symo inverter. If I connect to openems via modbus over TCP, it reads correctly the production value from the inverter. However, I have a (Fronius) smart meter which measures the grid connection, and it is connected to the inverter via modbus over some wires (so not on the home network).

How can I get openems to read that grid power value out? it is supposed to be Modbus device id 240 on the inverter.
Is there a ready made component in openems which I can use? (I did not find a generic modbus power meter)
Do I have to implement a new modbus meter class? Do I have to work on the Fronius PV inverter class such that it also acts as a grid power meter?

2

Hi alagi,

thanks for getting in touch!

So if I understand you correctly, Fronius provides the meter data via Modbus/TCP on Unit-ID 240. If this is true, you should be able to copy the code from the SolarEdge Grid-Meter implementation (https://github.com/OpenEMS/openems/blob/develop/io.openems.edge.solaredge/src/io/openems/edge/solaredge/gridmeter/Config.java).

Regards,
Stefan

3

Hello together,
Has anyone worked on this topic and can share their results so that no work is duplicated?

If I understand correctly, a completely new metre must be created, right?

Best regards,
Maik

4

Hi Maik,
there is an open Pull Request (PR2150) on the Fronius Gen24 Symo. I don’t see a meter implementation in it, but it could be a good starting point for you.

Unfortunately we were not able to make it a fully working ESS in OpenEMS. But in principle it should be possible, see this post

5

Hi Christian,

I have implemented the meter (Modbus RTU) readable via the Fronius Gen24 Symo (Modbus TCP).
I will now test your pull request, I only want to monitor the Gen24 in first step so it should work well.

Thanks for your answer