The fifth generation of process control system (FCS, Gansu non-standard automation equipment, Fieldbus Control System FCS): FCS is developed from the DCS, DCS as coming from CCS development as a qualitative leap. "Decentralized control" to "site control"; transmission of data using the "bus" approach. But the real difference is that the FCS FCS and DCS have a broader space for development. Because the traditional DCS technology although rising, but most low-end communications network only reached a site controller, contact the Texas non-standard automation equipment, field control station and field instrumentation, actuators still use one 4-20mA analog signal transmission, high cost, low efficiency, non-standard automation equipment, maintenance difficulties, can not play the potential of intelligent field instruments to achieve a comprehensive monitoring device for the automatic control of field work and the deep state management. Fieldbus is connected to the so-called intelligent measurement and control devices of all-digital, two-way transmission, a multi-branched structure node communication link. Simply put, it is a conventional control circuit, supply non-standard automation equipment, and FCS technology modules such as controllers, actuators, detectors, etc. hung on a bus for the communication, of course, is the transmission of digital signals. The main bus has Profibus, LonWorks and the like. In industry, for a variety of physical metallurgy, chemical industry, machinery manufacturing and other production encountered in the process, including temperature, flow, pressure, thickness, tension, speed, position, frequency, phase, etc., there is a corresponding control system. On this basis, through the use of digital computer also established a higher degree of automation and control and better performance of digital control systems, and has the control and management of the dual function of the process control system. Applications in agriculture include water level automatic control systems, agricultural machinery, automatic operation system. In terms of military technology, application examples of various types of automatic control servo system, fire control system, guidance and control systems. In the aerospace, aviation and maritime aspects, in addition to various forms of control systems, field of application also includes a navigation system, remote control systems and various emulators. In addition, the office automation, library management, transport management and even routine housework, automatic control technology also has a practical application. With the development of control theory and control technology, applications of automatic control system is still expanding, involving almost all areas of biology, medicine, ecology, economy and society.