Guides
Fanuc Alarm 021 Illegal Plane Axis Commanded: Fix
Fanuc alarm 021 means an arc was commanded with an axis outside the active plane. Here is why plane selection causes it and how to fix the offending block.
Lawrence Arya··5 min
Code reference
G17, G18, G19: Plane Selection in G-Code Explained
G17 selects the XY plane, G18 the XZ plane, and G19 the YZ plane. Here is what plane selection controls, why arcs depend on it, and when to switch.
Lawrence Arya··4 min