The CNC machine tool origin is the reference point adjusted by the machine tool manufacturer. The position of the specific machine tool origin is set by the machine tool manufacturer. The CNC system determines the specific position of the origin of the machine tool by returning the machine tool reference point, so as to establish a correct machine tool coordinate system. This is the function of the CNC machine tool returning to the machine tool reference point.

When the CNC machine tool position detection device is an absolute encoder, after the system is powered off, the encoder battery provides power to memorize the position change after the machine tool is powered off. When the system is powered on, the system exchanges data with the position detection device and the system refreshes the data. Make the coordinate value of the machine tool coordinate system consistent with the actual position of the machine tool. Therefore, when the position detection device is an absolute encoder, the machine tool does not need to return to the reference point of the machine when the machine is turned on. If the position detection device is an incremental encoder, the coordinate value memorized by the system is the position before the machine is powered off. Inconsistent, so the CNC machine tool startup of the incremental encoder position detection device must be operated by the machine reference point.

The relative coordinate value refers to the incremental coordinate value of the machine tool reference point moving from the machine tool origin to the machine tool reference point in the coordinate system with the machine tool origin as the coordinate origin (absolute coordinate value of each axis is 0); the absolute coordinate value refers to the In the coordinate system where the machine origin is the coordinate origin, the absolute value of the machine reference point in the coordinate system (the coordinate offset value of each axis is 0). The mechanical coordinate value refers to the absolute coordinate value of the machine tool reference point in the coordinate system with the machine tool reference point as the coordinate origin. Of course, the definition of the coordinate system of different machine tool manufacturers is different. In practice, it should be operated according to the machine tool manufacturer's machine manual.