G20 & G21 - Unit Selection Commands

Important: Galil Motion Controller Implementation

These commands do not directly affect machine operation because Galil's motion controllers operate in "counts" (encoder counts or step counts). The actual machine movement is determined by the "counts per unit" configuration value for each axis.

As long as the user defines all of their machine configuration and G-code commands using the same consistent units (either all inches or all millimeters), the machine will operate correctly regardless of which unit system is selected.