SLS signal inconsistency

What does A01691 mean?

An inconsistency has been detected in the safety input signals, specifically related to the Safe Limited Speed (SLS) function. The drive will initiate a controlled deceleration (SS1) and eventually enter a Safe Torque Off (STO) state, issuing a fault due to the potential compromise of safety integrity.

• Mismatch between redundant safety input signals for SLS (e.g., F-DI0 and F-DI1) indicating a fault in one of the channels.
• Defective safety sensor or switch providing inconsistent feedback for the SLS function to the drive's safety inputs.
• Cable breakage, short circuit, or high resistance in one of the safety input signal lines (e.g., between X150 terminal and safety sensor).
• External safety relay or safety controller providing incorrect or inconsistent signals to the drive's safety inputs.
• Internal fault within the drive's safety module responsible for monitoring SLS input signals and their redundancy.

Click steps to track your progress.

1. 1

   1. Verify the state of the redundant safety input signals (e.g., F-DI0 and F-DI1) directly at the drive's safety terminals (X150) using a multimeter (24VDC expected).

2. 2

   2. Check continuity and insulation resistance of the safety input cabling from the safety sensor or switch to the drive's X150 terminals.

3. 3

   3. Test the external safety sensor or switch used for SLS by manually actuating it and observing signal changes at the drive's inputs.

4. 4

   4. Inspect the drive's safety module diagnostic LEDs (if available) for specific indications of input channel failures or inconsistencies.

5. 5

   5. Perform a safety test of the SLS function as per the drive's safety manual to identify the exact point of inconsistency in the safety chain.