We are experiencing recurring safety faults on our Universal Robots unit during production use (robot operating continuously in a cooking environment).
The faults we are seeing:
C309A11 – Shoulder/Base: Keep-Alive Lost (Safety Control Board – Processor B)
“Lost 2 Keep-Alive messages in a row from Safety Control Board”
C306A0 – Joint Critical Error (Base joint)
“A critical error occurred in a joint”
These faults occur intermittently while the robot is actively moving (not during idle). A reboot clears the error temporarily, but the issue returns after some runtime.
You haven’t told us which robot or software version you are running, but give it a try with a software update.
I’m not familiar with the fault personally, but it could look like a watchdog of a sort for that joint. That’s something that actually could be improved in software updates.
If that doesn’t resolve your issue, then you have to contact your local distributor (or make a case on MyUR). Then the joint most likely will have to be replaced/repaired.
Actually we replaced the robot (ur5e) with the new one (ur7e) and still we have the issue.
Six months ago we had the same issue and we replaced the cable (robot cable that goes to controller box) and it was disappeared for six months. and now we recenetly have it back again.
Alright, so that points to a communication issue. Did you keep the control box or replace it, as well?
If you didn’t replace it, then the issue could be in there somewhere.
Is the error always associated with the shoulder joint?
Are you using an extended robot cable maybe? Or is there anything near the cable that can cause EMI and disrupt the communication?
Also. You should still look into updating the software on your robot to the latest, if you haven’t already.
