800F controller failure after profibus disruption
We recently had a customer that had an incident on their profibus. A contractor came in to rewire some of the signals coming in to VFD's that were in our profibus and shorted the profibus. The profibus is connected as per the attached drawing. They removed the profibus wires from one of the connectors in the drives seen in the common controller and shorted the red and green wires together.
So basically what we lost communication to al the IO clusters, which makes some sense, but then the controllers switched ( secondary to primary ) indicated by the following:
We then see that 1/2 hour later the following. When we go to look at the controller configuration, it appears to be empty.
I have seen something similar to this once before. Has anyone every had a similar experience to this? I guess we figured that once the profbus was back that we should start to communicate. We had to reload the controllers to get operational again. Not really sure what "First Adjustment not finished" means, is the first time seeing this in an SSL1 in Freelance. It also appears that we are missing some alarms from the alarm log during this time from other controllers.
Any help to understand what may have occured would be greatly appreciated.
Switching primary and secondary controllers is normal. If Profibus communication is configured but the controller does not find a
participant, a prim / sec switchover is initiated.
If there is still no participant on the bus, it is no longer possible to operate both controllers as a redundant pair.
I have never encountered a loss of the loaded program.
Was the pair of controllers really in sync at the time the Profibus was lost?