Fagor alarm E801: Encoder not detected (with motor feedback)
DDS drive display code (AXD/SPD/ACD/SCD seven-segment) · Fagor DDS drives
What it means
No motor feedback device answered at connector X4 although one should be present. Make sure the feedback is connected and healthy, and reconcile GP2 with the installed feedback type — e.g. GP2 set for sinusoidal encoder while a resolver is actually fitted. Sibling codes E802-E805 cover communication loss, initialization, defect and type-mismatch variants.
Likely causes
- feedback cable unplugged or broken (most common after crashes/maintenance)
- encoder electronics dead (no ID reply)
- GP2 feedback-type parameter wrong for installed device
- X4 connector pins damaged
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
- Request a quote →
Motor feedback cable (X4)
cable · Primary suspect
- Request a quote →
TTL/SinCoder encoder (motor-integrated, model-specific)
encoder · Common cause
- Request a quote →
Resolver (FKM/FXM motors)
encoder · Check if others ruled out
Need the part urgently?
Send us alarm E801 with your machine details — typical RFQ turnaround is 24–48h.