AC500 PLC Stopping without any Error
We are facing an issue with AC 500 PLC. Normally, when plant is in operation and all of sudden, PLC stops and all machinery goes offline. On further troubleshooting, we found that no errors are recorded and only 100% indication is shown in CPU statistics window. Now plant is again in normal operation and CPU usage is around 3%. Can you please support us understanding and resolving this peculiar behavior? Snapshots are attached herewith for your reference.
If you have a normal error then you should be able to connect Automation Builder to PLC. Task watchdog expiration is a normal error and you should be able connect the PLC. If you can't then you have some sort of firmware crash.
You need to do some investigation. I would probably start with:
1. How long was the system running before these issues started?
2. Is there anything common between the crashes?
3. Comment "Error Led turns on" do you mean that the Run led is still on but there isn't any execution?
4. Do you have the display for the PLC?
5. From the Information.png i assume you are using Automation builder 2.0.x. Newest version is 2.2.5, have you read all the Automation Builder release notes and checked if anything might be related to your situation?
6. Do you have modules at the I/O-bus and their installation is ok? No weird extensions or other issues?
7. Do you have some type of "special" communication at the Ethernet, Profinet or COM ports?
8. Do you have while or long (duration) for loops in your code?
9. Maybe you could create your own diagnosis with the Task Configurations System events and try to narrow down possibilities.