stevomyatt avatar image

VRM Instance Number Changed


Amongst a couple of firmware upgrades and factory resets to my Cerbo GX, two devices have changed VRM instance. E.g. Smart Solar MPPT changed from 278 to 279. This also affected a GX Tank 140 input.

Is there an explanation for this, and is there a way to move VRM history from 278 to 279? I do not want to lose the history for the original VRM instance device.



cerbo gx
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Weird one. Usually I have seen them chnage when they were unplugged and then plugged back in, especially if it went into a different port.

Or if was reset with nothing plugged in then reconnected to the system again as then it is a new device to the system

Otherwise never seen them change.

1 Answer
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi, this was an issue for VE.Direct connected products, up until Venus OS v2.65.

that version fixed the problem, by tying the used vrm instance number to the serial number of the connected BMV, Solar Charger, etc.

Every boot of Venus OS, it checks, for each connected vedirect product, if there already is is a reserved vrm instance number for its serialno, and then uses that.

And if not it reserves a new one.

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Thanks @mvader (Victron Energy) for the explanation, makes sense.

@mvader (Victron Energy),

Does this also apply to VE.Bus connected products like the MultiPlus?

The reason of my question:

In the last few days the VRM instance for the MultiPlus has gradually changed from 289 to 290 and 291. And since the firmware update this morning to Venus OS v2.80~44 back to 289. I can hardly keep up with changing the VRM widgest ;-)

In one case the reason was a change via VE.Config that triggered an automatic reset of the multi. Unfortunately, I had my GX Rpi connected to the AC Out...

The other changes to the VRM instance were each triggered by a firmware update from Venus OS.

I’ll find out. Could be its an issue only when using external MK3-USB, like on a pi..

Stefanie avatar image Stefanie ♦♦ mvader (Victron Energy) ♦♦ ·
Thanks. Yes, only VE.Bus affected. VE.Direct devices so far never have changed their VRM instance for me.