Energy meter missing (MRS)

Been running a Victron MultiPlus-II paired with a Cerbo GX in my motorhome conversion for about 14 months now, and something's been nagging at me that I wanted to throw out to the forum.

I'm using a Carlo Gavazzi EM24 energy meter on the AC input side to monitor grid draw when I'm on hookup, and for the most part it shows up fine in VRM. However, I've noticed that occasionally — seemingly at random — the meter just vanishes from the device list. No warning, no error flag in the Cerbo, it just disappears. Power cycle the EM24 and it comes back within a minute or two.

My suspicion is it's either:

• A VE.Bus timeout issue when the MultiPlus cycles between charging states
• Something to do with the RS-485 comms dropping momentarily under certain load conditions
• Or possibly firmware-related — I'm on Cerbo GX firmware v3.14

I'm also running a Fogstar 280Ah lithium bank with a JK BMS alongside this, so the system's reasonably busy talking to itself at any given time.

Has anyone else seen this behaviour — specifically the energy meter dropping off and reappearing without any obvious trigger? I'm wondering whether it's worth switching to a Victron Energy Meter VM-3P75CT instead, on the basis that native Victron kit might play nicer over the long run.

Would be particularly interested to hear from anyone running a similar setup on hook-up sites — whether that's motorhome, static cabin, or otherwise. Is this a known MRS (Meter Reading System) quirk or something specific to my install?

Hey @Smudge, looks like your post got cut off there mate! Did the forum eat the rest of it? 😄

Guessing from the thread title you're seeing an "Energy meter missing (MRS)" alarm on your Cerbo GX? That's a fairly common one. Usually means the Cerbo is expecting to communicate with an energy meter that it can't find - either via VE.Can or the RS-485 connection depending on your setup.

Worth checking your VRM portal to see if the device has disappeared from the device list entirely, or if it's just throwing the alarm intermittently. Also double-check your cable connections - vibration in a motorhome can work things loose over time.

What meter are you running alongside it? That'll help narrow things down once you post the rest of your message!

@Smudge classic case of the forum doing a Victron impression — showing you an error message with absolutely no useful context 😄

In all seriousness though, "Energy Meter Missing (MRS)" on the Cerbo typically means it's lost comms with whatever meter you've got on the VE.Can or USB. Few things to check:

Bit hard to comment without knowing what @Smudge was actually asking — thread title says "Energy meter missing (MRS)" so I'd guess it's about the MRS (Meter Reading System) alarm on the Cerbo GX, probably related to a EM24 or similar energy meter dropping off the grid.

Worth checking:

• VE.Bus connection still seated properly?
• Any recent firmware updates? Cerbo updates have occasionally broken meter comms in my experience
• Check Remote Console → Device List — does the meter show at all?

My garden office setup threw a similar wobble after a Cerbo update a few months back. Full power cycle of everything sorted it, annoyingly.

Would help enormously if @Smudge could actually finish their post though. 😄

Haha, looks like @Smudge and the forum are both having a bad day! 😄

Going off the thread title though — "Energy meter missing (MRS)" is a fairly common one on the Cerbo GX. Usually means the GX device has lost communication with a connected energy meter. Worth checking a few things while we wait for @Smudge to repost:

• Is the meter appearing at all under Settings > Devices on the GX?
• If it's a Victron meter on VE.Can, check your termination resistors
• Sometimes a simple power cycle of the Cerbo sorts it
• Also worth checking the firmware — there were some comms-related fixes in recent GX releases

@Smudge, once you manage to get your full question posted we can give you a proper answer! What meter are you using and how is it connected?