In short: is there a way to monitor the VE.Bus communication process on a GX device ?
TL;DR:
Yesterday 23/09 around noon (BE time) I got an alert that one of my (testing) setups had a battery mid-voltage alert.
Upon checking, the Multis were inverting and not seeing grid voltage.
In the Advanced page I can see that the evening before the grid voltage stopped being logged at 19:08 - likely because the Multis were software shutdown due to low load.
Logging restarted at 19:30 with VE Bus state “Inverting” and grid values flatlining at 0A and 226V - most likely the load increased and my Node Red flow restarted the Multis but for some reason they did not reconnect to the grid, ultimately triggering the battery alert the next day.
When I received the alert I tried to restart the VE.Bus system in the GX but that never completed - it got stuck at “Restarting…”
After a reboot of the GX everything magically returned to normal operation.
My guess is that “something” got stuck in the GX VE.Bus communication process with the Multis and that the GX was still receiving data from the Multis but couldn’t send data to them anymore.
This isn’t the first time I’ve encountered this and it seems to occur exclusively with this Multiplus (not the -II version) system.
Then again, it’s only on this system that I’m turning the Multis on and off with Node Red regularly (on a daily basis).
So maybe there’s a memory leak or something alike that triggers when the Multis are software turned on/off, eventually resulting in the VE.Bus process on the GX to get stuck.
Yes, I am aware that software turning Multis on and off is not typical usage, but there is a solid use case for it.
In my case it started at a construction site where power was only required during construction hours. Outside of those hours the Multis were software turned off with a Node Red flow to prevent battery drain by self consumption of the Multis.
About this system:
- 3x Multiplus 48/5000/70-100 (2624 version) running in 3 phase
- Cerbo GX MK2
- BMV-702
- ET340 as PV energy meter
- EM24 as grid meter
- System is running ESS
- All devices are running the latest firmware
Everything (grid & PV) is connected to AC In, AC Out is not used.
Batteries is 24x 2V 400Ah AGM in series.
One of the batteries has gone bad and some day I’ll fix that but since this is more a testing / proof of concept system that has a low priority.
I might have posted a similar topic before but I can’t find it anymore.
Edit: this happened ~6 days after upgrading the GX to v3.66.
Meanwhile I’ve made a minor change to my Node Red flow and will continue monitoring.