Set Feed Rate Mode — G93 and G94
Two feed rate modes are recognized: units per minute and inverse time. Program G94 to start the units per minute mode. Program G93 to start the inverse time mode. In units per minute feed rate mode, an F word (no, not that F word; we mean feedrate) is interpreted to mean the controlled point should move at a certain number of inches per minute,millimeters per minute, or degrees per minute, depending upon what length units are being used and which axis or axes are moving.
In inverse time feed rate mode, an F word means the move should be completed in [one divided by the F number] minutes. For example, if the F number is 2.0, the move should be completed in half a minute. When the inverse time feed rate mode is active, an F word must appear on every line which has a G1, G2, or G3 motion, and an F word on a line that does not have G1, G2, or G3 is ignored. Being in inverse time feed rate mode does not affect G0 (rapid traverse) motions. It is an error if:
• inverse time feed rate mode is active and a line with G1, G2, or G3 (explicitly or implicitly) does not have an F word.
G93 G94 Set Feed Rate Mode