Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 460

Troubleshooting Faults and Alarms
11.7 Drive Faults and Alarms Modulator Related
Fault display
Modulator watchdog flt
Loss of drive enable
458
Type Enable Potential causes and corrective actions
F Fixed Cause
Modulator detected that the CPU stopped communicating with it.
Action
1. Reset drive control power.
2. Check for proper grounding practices.
3. Replace DCR.
F SOP Cause
Modulator detected loss of drive enable.
Action
1. Reset drive control power.
2. Check for proper grounding practices.
NXGPro+ Control Manual
Operating Manual, A5E50491925A