Fanuc alarm SV0306: APC ALARM: OVER FLOW ERROR
servo APC alarm (absolute pulse coder) · Fanuc 0i-D
What it means
The amount of positional deviation overflowed while the CNC was trying to establish machine position from the absolute detector, so a valid position could not be obtained. This is normally a parameter problem: the flexible feed gear ratio set in parameters No. 2084/No. 2085 does not match the actual machine mechanics. Verify the FFG numerator/denominator against the ball screw lead and gear ratio before replacing any hardware.
Likely causes
- Incorrect flexible feed gear parameters No. 2084 / No. 2085
- Parameter loss after memory failure followed by wrong re-entry
- Mismatch between configured and actual detector resolution
Need the part urgently?
Send us alarm SV0306 with your machine details — typical RFQ turnaround is 24–48h.