Commonly used M function instruction rules for precision parts processing machine tools

Commonly used M function instruction rules for precision parts processing machine tools

In the use of precision parts processing machine tools, usually different machine tool manufacturers define different functions for some M commands, but some M commands have the same meaning on all machine tools. The figure below is a common M command table with the same meaning.

  1. The program pauses (M00)

After executing the M00 instruction, all machine movements are cut off for certain manual operations, such as accuracy detection, etc. After pressing the cycle start button again, the program after the M00 instruction will continue to be executed. This instruction is often used to pause the precision inspection between rough machining and precision part machining.

  1. Program selection stop (M01)

The execution process of M01 is similar to M00. The difference is that this instruction is valid only after pressing the “Select Stop” switch on the machine control panel, otherwise the machine tool continues to execute the following program. This command is often used to check some key dimensions of the workpiece.

  1. End of program (M20)

After the M20 instruction is executed, it means that all the contents in the processing program have been completed, but after the program ends, the execution cursor on the machine tool CRT screen does not return to the beginning of the program.

  1. End of program (M30)

On old-fashioned precision parts processing machine tools, M30 indicates the end of the paper tape. It has been widely used as a program end instruction at present, and its execution process is similar to M02. The difference is that when the program content ends, all machine actions such as the spindle and cutting fluid will be closed immediately, and the execution cursor on the machine tool display will return to the beginning of the program, ready for the next workpiece to be added.

  1. Spindle function (M03, M04, M05)

M03 is used for the spindle to rotate in the clockwise direction, M04 command is for the spindle to rotate in the counterclockwise direction, and the spindle is stopped by the command M05.

  1. Cutting fluid on and off (M08, M09)

The cutting fluid is open with M08, and it is closed with M09.

  1. Calling subroutine instructions (M98, M99) In the FANUC system, M98 is defined as the instruction to call the subroutine, and the M99 instruction is used when returning to the main program after the end of the subroutine.
Author: Chris Na