Fanuc alarm SP9091: POLE POSITION COUNT MISS
spindle alarm (serial spindle, alpha i) · Fanuc 0i-D
What it means
The magnetic pole position counting procedure failed: the drive could not complete the count that maps rotor angle to electrical phase. Synchronous torque control is impossible without this mapping, so the amplifier aborts startup of the spindle.
Likely causes
- Sensor signal dropout during the pole-count sequence
- Excessive friction preventing smooth rotation during counting
- Incorrect number-of-poles or sensor parameters
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
- View part →
A860-2000-T301
alpha i built-in motor sensor (Mi coder) · Check if others ruled out
Need the part urgently?
Send us alarm SP9091 with your machine details — typical RFQ turnaround is 24–48h.