Fanuc alarm SP9028: DISCONNECT C POS DETECT
spindle alarm (serial spindle, alpha i) · Fanuc 0i-D
What it means
The position detection signal for Cs contour control was lost. While the velocity channel alarm (SP9026) concerns speed feedback, this one indicates loss of the position feedback stream used to serve the spindle as a rotary axis in Cs mode.
Likely causes
- Position coder cable fault
- Coder head failure or air-gap misadjustment
- Parameter mismatch in Cs feedback assignment
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 SP9028 with your machine details — typical RFQ turnaround is 24–48h.