Fanuc alarm SP9026: DISCONNECT C VELOCITY DETECT
spindle alarm (serial spindle, alpha i) · Fanuc 0i-D
What it means
The velocity detection signal needed for Cs contour control was lost. When Cs mode engages, a separate position coder on the spindle provides speed feedback; its absence prevents closed-loop spindle speed regulation for contouring.
Likely causes
- Position coder cable disconnected or broken (JY series connector)
- Failed position coder pickup
- Incorrect Cs-related parameter selection
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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A860-0360-B101
Position coder (spindle encoder) · Check if others ruled out
Need the part urgently?
Send us alarm SP9026 with your machine details — typical RFQ turnaround is 24–48h.