Fanuc alarm SP9072: SPEED DETECTION RESULT MISMATCH (DUAL CHECK SAFETY)
spindle alarm (serial spindle, alpha i) · Fanuc 0i-D
What it means
The spindle amplifier's own speed-detection verdict disagrees with the independent speed judgment made by the CNC under Dual Check Safety. Because both channels must reach the same conclusion about spindle speed for the safety vote to pass, persistent disagreement forces a stop and implicates one of the two measurement chains.
Likely causes
- Faulty speed-measurement path in the SPM control board
- Degraded CNC-side CPU card responsible for the independent judgment
- Feedback signal quality poor enough that the two evaluations diverge
Need the part urgently?
Send us alarm SP9072 with your machine details — typical RFQ turnaround is 24–48h.