1 Brief description of DCS system development. DCS system is the abbreviation of Distributed Control System in English, and is the leading product of modern automation control technology. The development of automatic instruments has gone through three periods: the base instrument is the leading product of automatic instruments in the 1950s; In the 1960s, unit instruments and centralized computer control systems were mainly used; In the mid-1970s (1975), the emergence of DCS system represented by Honeywell TDC2000 in the United States and Yokogawa CENTUM in Japan played a revolutionary role in promoting the industrial automation field and was a milestone in the development of automation control technology. At present, distributed control system is still the mainstream product of automation control technology in the 21st century. The reason why DCS system can be widely used in petroleum, chemical industry, metallurgy, power, machinery, building automation, light textile, medicine, food processing, water treatment, industrial boiler and other industrial sites is that the development of computer hardware, high integration, high reliability and relatively cheap price make it possible for centralized computer control system to evolve into a decentralized control system. Decentralization of control functions contributes to the improvement of system reliability, which is one of the most important advantages of decentralized control systems, and is also the main reason for the rise and decline of decentralized control systems over the past 20 years. The earliest DCS in the world appeared in 1975-1976. The Ministry of Machinery of the People's Republic of China organized a forum in Tianjin, led by the Tianjin Institute of Industrial Automation and Instrumentation, to exchange the CENTUM system with Yokogawa Corporation of Japan. This is the first time that China has contacted the DCS system. Experts from Tianjin, Beijing, Shanghai, Xi'an and Chongqing have been sent to participate in the forum, opening the first page of the development of DCS in China. So Tianjin can also be called the cradle of DCS development, the research, development The application begins. At that time, Tianjin purchased a set of Yokogawa CENTUM DCS system of Japan for 700000 yuan (the price at that time), and began to digest, absorb, analyze and dissect. Then Jilin Chemical Industry Company also purchased the DCS system and used it in the chemical industry field. Since then, the introduction, application and development of China's DCS system have started successively. In the field of automation technology in China, there is a sentence in the field of computer application: "single board computer in the 1970s, PC in the 1980s, and DCS in the 1990s." This is a summary of this period. At present, China has introduced many distributed control systems from famous foreign companies, and the production and development of domestic distributed control systems have also made considerable progre...

Considering the hierarchical structure of DCS, the process control level and control management level are the two most basic links of DCS. The process control level realizes the decentralized control functions of signal input, transformation, operation and output. In different DCS, the control devices at the process control level are different, such as the process control unit, the field control station, the process interface unit, etc., but their structural forms are roughly the same, which can be collectively referred to as the field control unit FCU. The process management level is composed of engineer station, operator station, management computer, etc., which completes the centralized monitoring and management of the process control level. It is usually called the operation station. The hardware and software of DCS are designed according to the modular structure, so the development of DCS is actually to combine various basic modules provided by the system into a system according to actual needs. This process is called system configuration. (1) Field control unit The field control unit is generally far away from the control center and installed near the site. Its highly modular structure can be configured into process control units with different scales from several monitoring points to hundreds of monitoring points according to the needs of process monitoring and control. The structure of the field control unit is that many plug-in boards (or cards) with scattered functions are installed in the plug-in box according to a certain logical or physical order. The field control units and the control management level are connected by bus to realize information exchange. The hardware configuration of the field control unit needs to complete the following contents: Plug-in configuration Configure the host plug-in (CPU plug-in), power plug-in, I/O plug-in, communication plug-in and other hardware devices according to the system requirements and control scale; Hardware redundancy configuration Redundancy configuration of key equipment is an important means to improve the reliability of DCS. DCS can generally achieve redundancy configuration for host plug-in, power plug-in, communication plug-in and network, and key I/O plug-in. For DCS with different hardware installations, the installation of various plug-ins in the plug-in box will be specified in logical or physical order. In addition, the field control unit is usually divided into two types: basic type and extended type. The so-called basic type is that all kinds of plug-ins are installed in a plug-in box, but more often, the expandable structure is required, that is, a field control unit also includes several digital input/output expansion units, which are connected with each other by bus. In essence, the structural form and configuration requirements of the field control unit are consistent with the hardware configuration of the modular PLC. (2) Operation station The operation station displays a...

Rockwell's automatic control system has revolutionized the production of semiconductors - increasing the throughput of wafer processing by 25%, reducing the growth time of wafer from more than one year to six weeks, reducing 85%, and making the whole system more flexible and reliable. Background Information In the semiconductor industry, automation systems are used for wafer to chip processing. In this process, rapid thermal treatment, rapid thermal annealing and rapid thermochemical vapor deposition (RTCVD) are used to etch the surface of silicon wafer. The whole system, called cluster tool, consists of multiple processes, forming an automatic port with three process modules and a cooling chamber. The process module includes all kinds of automation equipment required for advanced semiconductor wafer processing. Traditionally, OEMs in the semiconductor industry use their own hardware and software component systems to control with C or other code programs. Developers of cluster tools found that working with complex programming languages increased development time and training needs, while computers often crashed and were difficult to adjust. In addition, the semiconductor industry needs a standard excuse to use multiple RS232 communication ports in system development. These complex requirements make the rapid and convenient development of the system face certain challenges. The problem was raised. A special developer of semiconductor cluster tools - also a supplier of IBM, Intel, Motorola, Toshiba and other companies - felt that the traditional method of controlling the wafer processing system had great room for improvement, which triggered the research of new technologies beyond traditional semiconductor technology. The company needs such a solution, which can manage and control the production process, control the special functions of each different module, and each module can carry out three axes Motion control. In addition, it needs a convenient and reliable interface for operators to input and feedback data. In order not to waste high cost purification space, the whole system must be compact, easy to install and configure. From the initial development of the processing system to the components of the whole system, most wafer processing companies need 12 to 14 months - this part of time must be reduced. Based on the previous experience of a manager, the company found Rockwell Automation and discussed the feasibility of Rockwell Automation's automation and control technology used in the semiconductor industry. Rockwell Automation provides the latest products, and the company also realizes that Allen-Bradley's programmable controller can provide the speed, flexibility, reliability and convenience required for the development and operation of the control system.