Fanuc alarm PS0020: OVER TOLERANCE OF RADIUS
PS alarm (program/operation) · Fanuc 0i-D
What it means
In an arc command, the radius calculated at the start point differs from the radius at the end point by more than the tolerance in parameter No. 3410. Usually indicates incorrect I/J/K or R values; with a large tolerance setting the path becomes a spiral instead.
Likely causes
- Wrong I/J/K center coordinates
- R-value arc where endpoints are inconsistent
- Rounding errors from a poor CAM post-processor
Need the part urgently?
Send us alarm PS0020 with your machine details — typical RFQ turnaround is 24–48h.