F08501 fault in siemens 6RA80 DC Drive indicate Setpoint timeout. This means the reception of setpoints from the COMM BOARD has been interrupted.

- bus connection interrupted.
- controller switched off.
- controller set into the STOP state.
- COMM BOARD defective.

• Restore the bus connection and set the controller to RUN.
• Check the set monitoring time if the error persists (p2040).