Controlling an ME 3000

Hi Ben,

Not related to your question, but I have the same setup and would love to know how you are controlling the ME 3000. I could never get it to accept any commands.

Hi, start a new thread describing your setup and what you’ve tried and I’ll reply to get you setup. Shouldn’t be too hard.


Hi Ben, what have you tried?

Have you set the inverter to passive mode?

Let me know.


I control mine using a Pi and some Python - specifically so I can have it run in auto during the day and control if and what it charges at during the Octopus Go cheap period.

Hi Ben,

Sorry, work is being a bear right now and I haven’t gotten around to starting a new thread. I’ll try and do it in more detail this evening but briefly I have a Modbus-TCP to Modbus-RTU converter connected to the RS-485 port of the inverter and I can use that to read data like state of charge from the inverter no problem.

What I can’t do is command the inverter via that channel, mainly because the commands seem to use non-standard Modbus function codes and I can’t find any libraries for Python or Node-Red that will let me send what they see as malformed messages. And my bit-banging skills are not quite up to fashioning the messages by hand!

I have tried putting the inverter into passive mode but as I said the problem is with sending appropriate messages, not at the inverter end (I think).

Have you tried using MODBus poll utility for windows.

This is how I debugged the comms for mine.

You can monitor the comms and see what’s happening.

Here’s a link to a GUI based Modbus analysis tool:

From: Modbus Software | Chipkin Automation Systems

Have you ever needed to analyze a series Modbus TCP message?
Are you having unexplainable problems with your Modbus devices?The CAS Modbus TCP Parser can analyze a series Modbus TCP message, displaying any error message, what data is being read/written and what device the messages are coming from, and more…Features:

Debug error messages in Modbus TCP messages
Reads Ethereal(r) capture logs
Simple to use
Free. (No email required)

There’s a couple of other Modbus tools on that page as well.