CU Safety Test Stop Fault

What does F01773 mean?

A safety test stop fault has occurred on the Control Unit (CU) side, specifically indicating that the expected states of the Digital Outputs (DOs) were not fulfilled during a safety test. This means the external readback signal was not set correctly for a given test stop state (e.g., state 7), where an expected value was not observed. This issue compromises the validation of safety functions.

Complete Troubleshooting Guide

1. 1

   Check the wiring of the F-DOs (Fail-Safe Digital Outputs) and their associated readback signals.

2. 2

   Restart the test stop procedure to attempt to clear the fault and re-evaluate the safety circuit.

3. 3

   If multiple test stop faults exist, clearing the current one will allow the next queued fault to be signaled for diagnosis.