Dear professionals and robotics enthusiasts,

Please I need your help! Recently, our UR is frequently showing a safety message (SafetyB: C192A16: Safety system fault: Safety output failed). It always shows randomly and it has largely affected the production process. Based on the log, the error code C192A16 always comes together with C192A18 (SafetyA: C192A18: Safety system fault: The other safety processor is in fault.).

We couldn't find any related solution online except referring to the manual. So far there is no short circuit found in the system. Someone who is experienced please help because we are quite new to the robot. Any advice is welcome to at least know where and how to start in solving this problem.

Much appreciated! :blush:

Thanks.

We’ve had that a couple of times and it has proven each time to be an intermittent short in the IO wiring. I would start with unplugging the IO blocks from the controller and see if the fault goes away then plug them in until it comes back. 

Thank you for your reply.

The problem is the robot is configured to run a sequence of processes and it only happens in a particular configuration (if it happened). So I think unplugging the IO blocks and testing each would be infeasible in our case as the robot is running in the production.

May I ask if the intermittent short in the IO wiring is only occurring at the connection points between wires? Or there might be some of the wires themselves are broken?

Thanks.

The last one I had to troubleshoot wound up being an unused wire from a bulkhead receptacle that was tied back but the end was not trimmed. It had been in production over a year without issue. While swapping a cable out it was bumped and would occasionally afterwards short out. We went through the cabinet and looked for loose wires, etc. 

We also had instances with broken/cut cables causing the issue.

Alright. We will definitely try this approach.

Besides, we just would like to narrow down the scope of the investigation. So would you think it is possible that the short circuit occurs from the internal system of the robot itself?

Thanks.

I’ve never experienced that with this code but anything is possible. It has generally been difficult to find but in every instance I’m aware of we’ve had something in the system that was causing the short. Does it happen every time at the same portion of code?  If so, look for an output that has shorted as it will only be evident when it turns on. Inputs can be the same way depending on how it’s shorted. I would start by looking at the code around where the fault occurs. See what inputs or outputs are turning on during that portion of the program.