Safe torque off

What does A5A0 mean?

The Safe Torque Off (STO) function is active, meaning the safety circuit signal(s) connected to the XSTO connector have been lost or are incorrect. This programmable warning, indicated by parameter 31.22 (STO indication run/stop), prevents the drive from generating torque, ensuring a safe machine state.

• Interruption or loss of the external safety circuit signals connected to the XSTO terminals.
• Faulty wiring, loose connections, or incorrect termination within the external safety circuit connected to the drive.
• Malfunction or activation of external safety devices (e.g., emergency stop buttons, safety gates, light curtains) linked to the STO circuit.
• Incorrect configuration of the STO function or parameter 31.22 (STO indication run/stop) within the drive.

Click steps to track your progress.

1. 1

   Inspect all external safety circuit connections to the drive's XSTO connector for proper wiring, secure termination, and continuity.

2. 2

   Verify the status of all safety devices and safety relays within the STO circuit to ensure they are in their intended safe state (e.g., emergency stop released, safety gate closed).

3. 3

   Measure the voltage at the XSTO input terminals to confirm the presence of the expected safety signal (e.g., 24VDC) when STO is intended to be inactive.

4. 4

   Review parameter 31.22 (STO indication run/stop) to ensure it is configured as desired for warning indication and corresponds to the application's safety requirements.

5. 5

   Consult the drive hardware manual and the safety circuit documentation for detailed STO wiring diagrams and specific troubleshooting procedures.