Fagor alarm 2001: X axis feedback error (same block as 2002-2009 for Y/Z/U/V/W/A/B/C)
CNC 8055 hardware/feedback error (analog axes) · Fagor 8055/8055i
What it means
The CNC receives no feedback signal from the axis (differential TTL or sinusoidal input dead). Monitored only when FBACKAL(P11)=ON.
Likely causes
- feedback cable broken or unplugged (A/B or inverted signals)
- linear scale or rotary encoder failure
- +5 V sensor supply shorted by damaged cable (blows CNC feedback input fuse)
- counter/axis board feedback input failed
Triage note: Setting FBACKAL(P11)=OFF silences the alarm but leaves the axis open-loop blind - temporary diagnostic step only. Swap X/Z feedback connectors first: if the error follows the connector, it is the scale/cable; if it stays, it is the CNC axis board.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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EC-P-D
Feedback cable SUB D15 HD (scale/encoder to CNC) · Primary suspect
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SX-520 (legacy) / S2X-320-5 (current)
Linear scale matched to axis travel · Common cause
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HP-1024-C5 / HA-22132-2500
Rotary encoder (rotary-axis machines) · Common cause
Need the part urgently?
Send us alarm 2001 with your machine details — typical RFQ turnaround is 24–48h.