question

paul-fairlight avatar image
paul-fairlight asked

Reading data from a multiplus-2

Dear all out there...

Although I have written whole solar home management software inc. smart socket integration and EpEver hardware I am new the the Victron range.

I would be eternally grateful if I could get some basic info using MODBUS on how to read data and control the inverter in the MultiPlus range for example...

1. Read solar voltage, current and maybe wattage (I could calc. this)

2. Switch the Inverter on/off

3. Read DC Battery voltage

A million tanks in advance for anyone's guidance.

Paul.


Multiplus-II
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2 Answers
nickdb avatar image
nickdb answered ·

Moved to modifications section. If you use the search feature, or even via google, you will find posts where this is already asked and answered, which should get you on your way.

Also look at node red.

All access requires a GX device to be connected to the inverter or a Pi via a MK3 USB adapter.

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paul-fairlight avatar image paul-fairlight commented ·
Hi Nick,

Thank you for your reply. My MultiPlus2 and Cerbo-GX are on their way to me as I write. I will be (with a little help with just just 1 MODBUS command to get me started) writing the code in VB6. Sure it's an old language but it does the job perfectly and is 100% stable.

I had a look at Code Red and looks very good but I'm working way down at machine level.

I'll continue my search...

Kind regards

Paul

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nickdb avatar image nickdb ♦♦ paul-fairlight commented ·

Just search for victron and modbus, you will find your way. Plenty of examples on the forum also. Good luck :)

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k-k avatar image k-k paul-fairlight commented ·

@paul-fairlight

sounds interesting (VB6) How do you manage the connection with modbus? Physical rs232 to rs485, using an api bound to a *.dll, or just 1024 bits via com1?

It seems to be that i must go in the dusty cellar and "oil the rusted harddiscs" in some '386. Sub Main : Option Explicit : Dim ModBus(1024) as .......

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paul-fairlight avatar image paul-fairlight k-k commented ·
So sorry for the late late reply. I simply used the Victron MK3 USB interface and a simple terminal program.

I've only just revisited this project and if you're interested I'd be happy to share what I find.

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Mike Dorsett avatar image
Mike Dorsett answered ·

If you are working with a lower level language, then you meed to look for the Victron document "communicating with VE bus products". I'll look out the reference later.

Multiplus has a native protocol, not modbus. I've developed a python interface to talk to mine. Cerbo has a modbus map, but uses the VE bus protocol fro the multi. You will need a Mk3 interface to talk directly to the multi. However, if you are communicating through the Cerbo, you can't use the Mk3 at the same time.

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