Mk3 adapter not talking to GX device

DIY
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1

Hi all,

I have a GX device i have removed from my second multiplus unit that is running in parallel on my house.

I purchased 2 multiplus GX devices to have one as a spare incase one broke.

I want to use this device in my caravan which will have a victron setup. Essentially, i am wanting to get out of purchasing a Cerbo unit to collate the telemetry etc…

I have removed the PCB, and its sitting on my desk and i have connected my MK3 into the VEbus port on the PCB that would normally connect to (what i assume) is the VEbus port on the multiplus internal controller board.

However, it does not show up in VEconfigure.

The GX unit is configured as a mirror of my other unit, and i want to wipe its config and reset it to essentially factory.

My caravan will be all 24V and will have a Batrium BMS for the lithium (which i need a canbus port for to integrate it to control the chargers) and it will have some of the Victron MPPT controllers connected to the GX device using VEdirect.

However, my issue is that i cant get it to recognise the unit using the MK3. so seeking some advice on if its compatible to do this.

2

Probably because that is not how it is designed to be used that way.
The GX has several access methods (if it is powered up). The mk3 is not one of them.

What PCB did you remove exactly? The GX Pi?

[Reset to factory procedure is here.]

3

hey there, i understand that its not meant to be used in this way exactly. its more a case of leveraging the hardware i have to suit the intended purpose.

I removed the PVB thats inside the multiplus that is the GX part, connected to the screen etc… It has power and an ethernet cable (presuming that this is the vebus connection to the multi)

If this wont do what i want, im happy to go down the Rpi route, i flashed one with Venus, i am just to cheap to buy the canbus adaptor for it as they are quite expensive here. hence seeing if i can use the spare GX i already have :slight_smile:

I did also see the reset file, i was hoping if i can get access to the unit, I can do it using veconfigure or similar :slight_smile:

Jason

4

You can use the GX outside the inverter. I am wondering what the reason for the mk3 connected to it is for?
It has no use (besides an mk3 function test). What you can to is flip it around and connect an inverter to the GX through the usb but for monitoring not control. But usually as you know you want to use the ve bus
But resetting is done a completely different way.

5

A GX device is not configured through the VE Bus or even with VE Configure, but over Ethernet/Wifi or Bluetooth.
The VE Bus on the GX and the MK3-USB adapter serves only to manage Multiplus devices.
I’m not familiar with the embedded GX devices so I can’t tell if the RJ45 port you plugged your cable in is VE Bus, CAN or Ethernet.

From the Datasheet:
The integrated GX device includes:
• A BMS-Can interface. This can be used to connect to a compatible CAN-bus managed battery. Note that this not a VE.Can compatible port.
• A USB port.
• A Ethernet port.
• A VE.Direct port.

Note that it doesn’t have a VE Bus port.
I presume that VE Bus communication with the Multi GX you took it out of takes place over the pins that plug in to the Multi GX.
So you should have an RJ45 connector for Ethernet and one for BMS-CAN.

Your best bet is to check if you can see the GX device via Bluetooth, Wifi or on your Ethernet network and then take it from there.
If you can find the BMS-CAN port, you’re good to go using that to connect to your BMS.
Otherwise my recommendation would be to bite the bullet and either buy a Cerbo or a Pi with a supported CAN Hat.

6

Hi all

Thanks for the comments. I understand now that the VEbus is only plugged into the multi to configure it, and the GX essentially reads the config from it and reports.

This was a gap in my understanding.

I have reset the unit to factory (hot tip, you dont need to faf around with the whole usb stick thing, if you have shell access, you can just run the command that the reset tool does and reboot and your away. I will write a post on that elsewhere)

I have now got it configured as expected. It would be good if i could remove some of the options from the list, as they wont be used (ESS, Energy Meters and PV inverters) as its all in a caravan. but im not sure if i can. However i have come across GUI mods which should do what i want if i want to alter it from the existing display.

There is also a VEbus connector on the inbuilt GX, this is connected to the multiplus using a ~250mm cable. This would be how the multi communicates data to Venus.

And yes, the MK3 does connect to the VEbus ports on the PCB that is part of the multplus, and not the GX.

on the PCB there are

  • 1 x VEbus
  • 2 x VEcan
  • 1 x USB
  • 1 x ethernet
  • 2 x VEdirect

The VEbus and 1 of the VEdirect are internal, as it would be the same unit used with an easy solar, which is essentially a multi with a MPPT inbuilt, and this would use VEdirect to talk. And then the other VEdirect is on the bottom edge, with the CAN, USB and the ethernet for external devices etc…

I will do a full build and write up as i plan to use my spare Batrium as the BMS (using Can), 4 x 75/15s using VEdirect, and ethernet to log it all and what not. Should be an exciting build :slight_smile:

Once again, thanks for the help.

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