Fagor alarm 4091: ERROR 500: Incoherent parameters
CNC 8055 SERCOS drive error (DDS) · Fagor DDS drives
What it means
The drive's stored parameter set is internally inconsistent (values contradict each other or the hardware configuration). The error deactivates PWM (category 0 stop) and cannot be cleared by reset - reload correct parameters and power-cycle. The CNC remains stopped until the drive completes a healthy start-up.
Likely causes
- Corrupted drive parameter memory
- Parameters from a different motor/model flashed into the drive
- Interrupted parameter download leaving mixed versions
Triage note: Re-download the .MOT/parameter file with WinDDSSetup and cycle power.
Need the part urgently?
Send us alarm 4091 with your machine details — typical RFQ turnaround is 24–48h.