Test stop for STO via terminals at the PM required

What does A01678 mean?

The set time (p9661) for monitoring the forced checking procedure (test stop) for the 'STO via Power Module terminals' function has been exceeded. This indicates an overdue safety test that must be performed to maintain the integrity of the Safe Torque Off function.

• The scheduled test stop for Safe Torque Off (STO) via Power Module (PM) terminals has not been performed within the interval defined by p9661.
• Test stop procedure initiated but not completed successfully due to an external interlock or communication issue.
• Timer p9661 for test stop monitoring is set too short for the operational environment or maintenance schedule.
• A safety logic controller (PLC) or external safety circuit has failed to trigger the required STO test.

Click steps to track your progress.

1. 1

   1. Initiate the STO test stop procedure as described in the safety manual, typically by deactivating and reactivating the STO inputs on the PM terminals (e.g., X124/X125).

2. 2

   2. Monitor the status bits (e.g., r9756) to confirm successful completion of the STO test stop.

3. 3

   3. Review parameter p9661 to ensure the test interval is appropriate for the application and maintenance schedule, adjusting it if necessary.

4. 4

   4. Verify the external safety circuit responsible for triggering the STO test stop is functioning correctly by checking its output signals to the PM.

5. 5

   5. Log the completion of the STO test stop in the maintenance records.