Strange: one dimmer channel group address changed by itself?

Hi everyone,

I’ve run into a really odd issue and I’m hoping someone can explain how this could happen.

A light circuit in my master bedroom suddenly stopped responding to CBus control. Commands were definitely being sent (I could see the CBus log), but the channel LED on my L5508D1A dimmer wouldn’t come on and the light stayed off. The weird part is: if I pressed the button/led for that channel on the dimmer, the light came on — so the load and the channel itself seem fine.

I power-cycled the whole CBus network (off for ~20 seconds) and it made no difference.

After scratching my head for ages, I finally found the reason: that channel’s Group Address had somehow changed from 33 to 55. As soon as I set it back to 33, everything started working normally again.

What I can’t wrap my head around is… I haven’t been in Toolkit changing anything recently, and nobody else has been programming the system. So how on earth does a single channel’s GA just change like that?

Any thoughts would be appreciated — it’s a bit unsettling when something like this changes by itself.

Thanks!

 

Any Chance Learn Mode is enabled (it normally is by default)
So by operating from the front panel, if you accidentally enter learn mode, then its possible for the channel to change group.
You can disable units from entering learn mode. which is my advice.
All you need to do is think the front buttons are able to DIM and hold it down for too long to enter learn mode.