The numerical control device of the machine tool (commonly known as the numerical control system) is a special electronic computer that controls the machine tool and completes the automatic processing of the parts. It receives the digitized part pattern and process requirements and other information, performs interpolation calculation according to a certain mathematical model, and uses the operation result to control the speed and position of each motion coordinate of the machine tool in real time to complete the processing of the part. The overall block diagram of the CNC machine tool is shown in Figure 1. With the advancement of science and technology, especially the development of microelectronics technology and computer technology, CNC systems have been rapidly developed with the latest hardware and software resources. Each famous CNC system manufacturer has a new type of CNC system product born every three years. The application of CNC machine tools has also been applied to various occasions from solving difficult parts processing, automated production of batch parts, to entering home workshops. At the same time, it has also put forward new requirements for hardware and software of CNC systems. It is concentrated in the functions of CNC systems that require an open structure, adaptive technology development, and user-developed functions. At present, some developed countries and regions, such as Europe, the United States, and Japan, have successively conducted research and development of open-structure CNC systems, such as the OSACA (Open System Architecture for Control Within Automation) program in Europe. The US Next Generation workstation/machine controller architecture (NGC) program. The basic structure of the open CNC system includes a hardware platform, a software platform, a user-extendable hardware and software space, and an application development environment. Hardware platform: provided by the CNC system manufacturer, or choose a common standard module, but its configuration can be selected by the user in a wide range, such as the number of control axes, control methods, various external devices. Software platform: provided by the CNC system manufacturer, or provided by the CNC software developer. It is the core software of the system, namely the basic software of CNC and PLC, and provides a good environment for users to develop application software. Application software: Based on the hardware and software platform provided by the CNC system manufacturer, the user develops special software and hardware to realize the control functions required by the user. The rapid development and wide application of personal computers (Personal Computers - PCs) provides an effective way for us to develop PC-based, open-structure CNC systems. Since its inception in the early 1980s, PCs have become mainstream computers in various fields and have been widely used in process control and automation. PC's main frequency has reached 450MHz, can meet the requirements of various CNC high-speed real-time control systems, rich software resources, such as DOS, Windows, C language and other development tools, a large number of available external devices, such as CRT, flat panel display, CD Hardware support for drives, floppy drives, hard drives, keyboards, etc. The chip integration of PCs is getting higher and higher, and the output of PCs is increasing year by year. This provides conditions for PC-based CNC systems to reduce the size and cost performance, because PC-based CNC systems make full use of PCs. The hardware and software resources can continue to adopt new technologies following the development of PCs. Early use of Intel 80286, 80386, now Pentium III, operating system from DOS to Windows, etc., so PC-based CNC system is getting faster and faster development and application. There are three kinds of PC-based CNC system structure: the first one is to install the CNC special hardware and software developed by the CNC system manufacturer to the motherboard of the PC, and use ISA or PCI bus to retain the overall image of the original PC. ,as shown in picture 2. Figure 2 Structure of the CNC dedicated template loaded into the PC motherboard The second type is the CNC system production plant, which is embedded in the motherboard of the PC in the CNC system produced by itself. This embedded structure shows the overall structural characteristics of the production plant, using the dedicated bus or hybrid bus structure of the production plant, such as Figure 3 shows. Figure 3 Structure of the PC motherboard embedded in the CNC system The third is to make the PC communicate with the high-speed serial port bus (or ARCNET, etc.) and the dedicated hardware and software developed by the CNC system manufacturer via the optical cable, as shown in Figure 4. Figure 4 Structure of PC and CNC dedicated hardware and software communication via optical cable network Wall-Mounted Basin Faucets,Wall Mounted Bathroom Faucet,Wall-Mounted Faucets For Modern Basin,Wall Mounted Concealed Basin Faucet Kaiping Jenor Sanitary Ware Co., Ltd , https://www.kpjenorsanitary.com
Figure 1 Overall block diagram of CNC machine tools 
