A preparatory function in CNC programming is known as what?

The correct choice, G-Code, refers to a set of instructions that tell the CNC machine how to perform various functions, including moving to specific coordinates, controlling feed rates, and implementing tool changes. G-Codes are essential for CNC programming as they define the preparatory functions necessary for machining operations. These codes dictate how the machine interprets movements and processes, allowing it to execute precise operations.

In contrast, M-Codes are primarily used for miscellaneous functions such as starting and stopping the spindle and controlling coolant flows. Absolute and incremental positioning refer to methods of defining movement in CNC programming—absolute positioning establishes locations based on a fixed coordinate system, while incremental positioning refers to movements based on the last position. These concepts, while related to operational parameters, do not classify as preparatory functions. Thus, G-Code stands out as the appropriate term for preparatory functions in this context.