Fagor alarm E818: FAGOR SSI: Error on the absolute track (analog signal < 0.20 Vpp)
DDS drive display code (AXD/SPD/ACD/SCD seven-segment) · Fagor DDS drives
What it means
SSI absolute position cannot be calculated because the incremental track amplitude collapsed below ~0.2 Vpp - counting lost.
Likely causes
- glass scale or steel tape contaminated/scratched
- traverse speed beyond encoder rating skipping tracks
- mounting tolerance (gap/parallelism) violated
- reader head/encoder internally failed
Triage note: Escalation ladder straight from the manual: check speed rating -> verify mounting tolerances -> CLEAN glass/tape -> replace encoder/head. Mirrors CNC alarm 4184.
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
- Request a quote →
LA-840
LA absolute linear scale (tape clean or replace) · Primary suspect
- Request a quote →
HAF-27-D170-2
Absolute angular encoder (rotary installs) · Common cause
Need the part urgently?
Send us alarm E818 with your machine details — typical RFQ turnaround is 24–48h.