F01800 fault in siemens 6RA80 DC Drive indicate Hardware/configuration error. This means a DRIVE-CLiQ connection fault has occurred.

1. Ensure that the DRIVE-CLiQ components have the same firmware versions.
2. Avoid longer topologies for short current controller clock cycles.
3. Check the DRIVE-CLiQ cables at the Control Unit.
4. Remove any short-circuit for motors with DRIVE-CLiQ.
5. Carry out a POWER ON.