Fanuc Parameter 1860 Full _best_ -

The reference position is not established . The machine does not know its absolute zero, and you will likely see a "Need ZRN" (Zero Return) alarm or a 300-series absolute pulse coder alarm.

The machine cuts perfect straight lines but oval arcs. This is often a mismatch between 1860 and the acceleration for the orthogonal axes. Ensure that the 1860 values for X and Y (or X and Z) are identical for circular moves. Uneven acceleration distorts circles into ellipses. fanuc parameter 1860 full

: In machines without counterweights, a spindle may droop during an E-stop before the brake engages. Parameter 1860 will record this displacement, which can lead to slight discrepancies in homing if not accounted for. Zeroing Procedure The reference position is not established