Controlling an ME 3000

Hardware
1

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.

2

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.

Ben

3

Hi Ben, what have you tried?

Have you set the inverter to passive mode?

Let me know.

Ben

4

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.

5

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).

6

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.

7

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.