Fagor alarm E157: Too much difference in actual position between the two feedbacks (PP5)
DDS drive display code (AXD/SPD/ACD/SCD seven-segment) · Fagor DDS drives
What it means
Deviation between motor feedback and direct (linear scale) feedback exceeded PP5 ActualPositionMonitoringWindow for >20 ms - the two measurement systems disagree.
Likely causes
- lost motion between motor and scale: ballscrew backlash, coupling slip, belt jump
- direct feedback cable/heads marginal (counts dropping on one system only)
- feedback parameterization wrong (NP133 pitch, ratio NP117) after service
Triage note: Diagnostic gold: command slow full-travel move, log PV188 (motor) vs PV190 (direct) - whichever trace steps backward/flat spots identifies the failing system before any parts are bought. Mirrors CNC alarm 4132.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
- Request a quote →
SX-520 / S2X-320-5 (match axis)
Direct linear scale · Common cause
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EC-P-D
Scale feedback cable · Common cause
- Request a quote →
FXM34.40A (if motor-side drifts)
Motor with integral feedback · Check if others ruled out
Need the part urgently?
Send us alarm E157 with your machine details — typical RFQ turnaround is 24–48h.