A complete set of numerical control (CNC) machine tools system usually consists of the following key parts: Information input and output devices, including disk drives, dedicated data interface devices, keyboards, computers, etc., are used for program entry, modification and transmission. The network connection system, including Ethernet interface, HSSB, processing local area network, RS-232C communication port and other industrial networks, is used to achieve communication and data sharing with external devices or systems. External mechanical axis control units, such as automatic table changing devices, loading and unloading robots, tool magazine drive axes, etc., are used to assist in the automatic switching and positioning of workpieces or tools during the processing.