DCS distributed control system is the abbreviation (Distributed Control System), in the domestic automation industry is also known as distributed control system. With respect to a new computer control system of centralized control system is concerned, it is based on a centralized control system on the development, it evolved.

    First, DCS skeleton - system network, which is the foundation and core of the DCS. As the network for real-time performance, reliability and scalability of the system DCS, it plays a decisive role, so the manufacturers have in this regard has been carefully designed. For DCS system network, it must meet the requirements of real-time, to complete the transfer of information within the time limits established. Here the word "OK" time limit, means that in either case, the information transmitted can be completed within this time limit, and this time limit is determined based on the real-time requirements of the controlled process. Therefore, the network speed indicators are not a measure of performance of the network system, known as the number (bps) bits per second, but the real-time system network that is able to ensure the transmission of information required in a long time to complete . System network must also be very reliable, in no case, network traffic will not be interrupted, so most manufacturers are using DCS dual-bus network topology, ring or double star. In order to meet the system requirements of scalability, the maximum number of nodes on the network can access the system should be greater than the actual number of nodes several times. On the one hand you can always add a new node, it also allows the system to run on network traffic light load conditions to ensure timeliness and reliability of the system. In actual operation system, the Internet and the net each node is likely to occur at any time, particularly in the operator station, so that the network will often be reconstructed, and this operation must not affect the normal operation of the system, so the system The network should have a strong online network reconfiguration capabilities.

     Secondly, this is a completely on-site I / O processing and direct digital control (DDC) network node functions. Usually you want to set the scene of a DCS I / O stations to share I / O and control functions of the entire system. Such a site can be avoided due to the failure cause failure of the entire system, improve system reliability, the site also allows sharing of data acquisition and control functions, helping improve overall system performance. DCS operator station is to deal with all operations related to running the network node machine interface (HMI-Human Machine Interface or operator interface) functions.

    DCS engineering station is off-line configuration, system configuration work and supervise online, control, maintenance of network nodes, its main function is to provide DCS configuration, software configuration tool for the job (ie, configuration software), and monitor the operation of each node on the network in real time in the DCS DCS-line running, the system engineer can adjust a number of system configurations and system parameters set by the engineering station, so that at any time in the DCS under the best working condition. And centralized control systems, are required to have all of the DCS system configuration functions, it can be said, no system configuration function of the system can not be called as a DCS.

    DCS since 1975 inception, has experienced more than 30 years of development. In thirty years, although DCS no major change in the architecture of the system, but through continuous development and improvement of its functionality and performance has been a huge increase. Overall, DCS is toward more open, more standardized, more product-oriented direction.

    As a computer-controlled production process automation system, the traditional DCS is only a narrow concept. If you think that only DCS automation system process, it will lead to the wrong conclusion, because the meaning of the present computer control system has been greatly expanded, which includes not only a variety of content in the past DCS included, further down deep into the each scene of the measuring equipment, actuators, up to the development of production management, business aspects. DCS traditional sense now refers only to this part of the production process control automation, and the concept of industrial automation systems, it should be targeted to enterprise-wide solution that total solution level. Only from this point on to ask questions and solve problems for the computer to automate really play its due role.

DCS has the following characteristics:

    1. High reliability. Since the DCS system control functions will be dispersed on each computer implemented system architecture using fault-tolerant design, so the failure of a computer that appears does not cause loss of function of other systems. In addition, because each computer system tasks undertaken relatively simple, you can achieve the functions required for using a dedicated computer and software with a specific structure, so that each computer system reliability is also improved.

    2. Openness. DCS an open, standardized, modular and serial design, each computer system using the LAN communicate, to transmit information, when you need to change or expand the system functionality can be easily connected to the new computer system or communication network Remove from the network, almost does not affect the work of other computer systems.