Fanuc alarm SV0301: APC ALARM: n-TH AXIS COMMUNICATION ERROR
0i-D servo APC alarm · Fanuc 0i-D
What it means
Serial communication between CNC and absolute pulse coder failed (DTER/CRC class error) - position cannot be read
Likely causes
- encoder feedback cable damaged/oil-soaked connector
- pulse coder failure
- servo amplifier side-board (interface) fault
- noise from bundled power cables
Triage note: Wiggle-test/wiggle the connector while watching the alarm; if alarm follows cable movement replace cable, else swap pulse coder
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
- View part →
A860-2000-T301
Pulse Coder (alpha iA1000) · Common cause
- Request a quote →
A06B-6134-K003
Encoder Feedback Cable Set (beta i motor) · Common cause
Need the part urgently?
Send us alarm SV0301 with your machine details — typical RFQ turnaround is 24–48h.