F1611 fault in siemens sinamics V90 drive indicates a Safety Integrated (SI) Defect Detected on the Control Unit. This means the internal safety monitoring system found a critical fault and triggered a Safe Torque Off (STO) to protect the machine.
Cause:
The drive-integrated “Safety Integrated” (SI) function on the Control Unit (CU) has detected an error and initiated an STO.
Remedy:
- Carry out a POWER ON (power off/on) for all components.
- Upgrade software.
- Replace the Control Unit.
