Which function must be selected to utilize an M01 command?

The M01 command is known as the "Optional Stop" function in CNC programming. When the M01 command is included in a program, it signifies a point in the program where the machine can stop if the operator has the optional stop function activated. This allows the operator to pause the execution of the program for inspection or tool changes at selected points without disrupting the flow of the machining process.

Selecting the optional stop enables operators to maintain control over the machining process and decide when to halt operations. If the optional stop is not activated in the program, the machine will ignore the M01 command and continue executing the program without stopping. This feature is particularly useful for quality checks or maintenance tasks that may need to be performed intermittently during the machining process.

In contrast, other options like tool change, program stop, and rapid traverse serve different purposes within the CNC program and do not directly relate to the function of the M01 command. Tool change is typically associated with M06, program stop pertains to M00, and rapid traverse involves commands that control movement speeds rather than stopping operations for optional inspections.