There are various error sources, e.g.:
Memory error, e.g., faulty flash memory
Desigo PX stops working.
Desigo PX continues working.
Failure of backup server recognized by primary server
Desigo PX recognizes the fault and transmits the relevant alarm.
Non-critical errors / configuration errors
Non-critical hardware and software errors are identified by Desigo PX and registered as a device object alarm.
When a critical hardware or software error occurs, the automation station tries to restart. If the same error is detected three times within 15 minutes, the automation station switches to the COMA operating state. If the Fault LED is lit, the automation station is in the COMA operating state.
Online properties for diagnostics
The values in the Online Properties window in Xworks Plus (XWP) give clues about the operation of the automation station.