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Bernhard Matschinger avatar image
Bernhard Matschinger asked

ModbusTCP Sunspec --> Standard or Not?

Hello Everyone!

Looking for a solution to implement a Kostal 3Phase Inverter via ModbusTCP to a Venus GX.

What I came up with:

I already have a different Installation running Sunspec for a Solaredge --> Setting Device ID126 and getting that Inverter Connected to my GX device (running almost a year)

With a new installation I have a Kostal, that has ModbusTCP implemented, but not working on a GX Device..

  • Basically I enabled Modbus TCP on the Inverter
  • I redirected the not changeable Modbusport 1502 to 502 via an external rerouting
  • I Changed the device ID from 71 to 126 (as well to quircks the GX)
  • (I checked all Sunspec Register with an external Software I wrote and get all infos)

But now things are different

On SolarEdge ModbusTCP Registerlist starts at 40070 with all necessary data

on Kostal ist starts on 40071

So the GX Device does not understand what s going on because of that one Address Shift


My question:

Has anybody connected a PV Inverter with different PORT and a different Initial ModbusTCP Register Starting Address?


Or from the other side:

Is it possible to change the Settings in the VE device via SSH, or do I have to Implement an external device or write my own internal Codeblock to get things running.


Answers highly appreciated

Greets

Bernhard Matschinger / Msol GmbH
https://www.msol.at


Venus OSModbus TCPsunspec
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1 Answer
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi Bernhard, I cant help technically (there is no setting, and our pvinverter driver code is -partially- closed source.

External device might be possible & internal code block is possible (but I expect it to be quite some work; probably easiest to add into the existing modbus-client driver that you’ll find in v2.60 beta series. Its written in Python. Either really add it in, or make a copy ).


but I am curious: why go through all that trouble instead of using one of the already supported brands and or a few hundred euros energy meter instead? If its for the challenge, I’d understand. But commercially I do not?

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mvader (Victron Energy) avatar image mvader (Victron Energy) ♦♦ commented ·

Ps. Sounds like Kostal is purposefully deviating from the real standard.

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Modbus TCP Basics

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