What is the purpose of M-codes in FANUC programming?

M-codes serve a crucial role in FANUC programming as they are designed for miscellaneous functions that enhance the operation of CNC machines. These functions can include actions such as starting and stopping the spindle, changing tools, controlling coolant flow, and other operations that do not directly relate to the movement of the machine's axes. By using M-codes, machinists can streamline and control various machine operations effectively.

In contrast, while initializing machines may involve some use of M-codes, it is not their primary purpose. M-codes are also not intended for programming errors; they do not address issues related to code correctness or logic. Moreover, while safety checks can be part of machine operation, M-codes are not specifically designated for safety protocols but rather for operational control. Thus, the answer highlighting the use of M-codes for miscellaneous functions accurately captures their integral role in the programming and operation of CNC machines.