【正文】 2, the warning window: By arranging the time order way (namely the most emerging alarm ranks the top of the window ) and listing the unusual situation appearing in production processes , if number value restricts . Reporting to the police should include time , unusual state and value , confirming by operator and unusual brief illustration to tabulate already of the unusual data to unusually appear 。s standing , engineer that can also receive , in order to realize that establishes artificial control or parameter to our station of the scene. 3, calculation and closing ring controlling , in order to control etc. IN realizing the part and automaticallying control in our station , return circuit , algorithm whose some classical algorithm generally, can remove theatrical makeup and costume nonstandard algorithm , plicated algorithm. Operator39。 Facing DCS supervise the administrative staff39。中文 6790字 DCS principle and PLC foundation DCS principle Distributed Control System (DCS) carries on the centralism monitor, the operation, the management and the disperser control which is one kind of new control technology using the puter technology to the production process. DCS is base on the puter technology, the signal processing technology, the survey control technology, the correspondence work technology, the CRT technology, the graphical display technology and the manmachine connection technology mutually seeps the development to produce. DCS both is different with the dispersible measuring appliance control, and different with Yuji Chinese type puter control system, but overes the two flaw to concentrate the two superiority, it has concentrated function and so on step less control, batch control, logic sequential control, data acquisition. Basic ponent of DCS The logic structure of the system needs realizing by the physics structure. We can sum up their physics structure as the structure of the type of a gleam of past three simply . first line refers to its skeleton puter work, the three means that join three kinds of different kinds of nodes in the work: Face onthespot I/O which is accused of the course scene to control and stand。s station。s station , standing and other engineers live through the work FO control the station, in order to realize the supervision and control of the whole system, at the same time it is stood the message issued by operator39。s main manmachine interface equipment of the station outputs the respect in the puter, which control the equipment for industry keyboard and cursor in importing in puter (such as the mouse, orbit ball). The content outputted on CRT includes mainly: 1, the simulation flow chart of the production process (namely by imitating production device and production line that the figure expresses), which wins a bid of realtime status with all key data ,to control parameter and equipment。s own work each. If none of unified coordination can not form the intact system, the systematic work offers the foundation for coordinating , which bees the core of the whole system. 1, Network characteristic Different from some work that general office automation adopts, the munication work that DCS adopts was used for the control and management of have the industrial production process, so, it should possess the characteristics of the following : ● Realtime character is good, respond fast dynamically ● Meet the abominable onthespot environment of industry ● Dependability is high ● Opening is good 2, Network structure Early LAN with better realtime character of often adopt making brand total work or to make the card surround the work alone etc. of information management work of DCS control system. But no matter domestic or abroad, which uses most is CSMA/CD Ether at present. Ether enters industry and es from its low cost , opening , extensive development and support of using the software and hardware live, what it uses the most extensive work technology at present. The industrial control work adopts Ether, and can make the industrial control work incorporate the development mainstream of the work technology of the puter . DCS controller function block: DCS not only able to plete the functions of the original analog instruments, and much higher than analog instruments. This is because it uses advanced puter technology, munication technology, CRT technology and control technology 4C technology. Using digital control after the predeposited in the controller ROM of the algorithm is infinite, each representative of an algorithm kinds of functions. These features in the simulated instrument is achieved with analog circuits, which are analog line drift, resistors, capacitors and other devices restricted, as a high precision analog meter high cost, or even almost impossible. The digital control algorithm is implemented with the program. With a program to replace the analog line can realize the function. Theoretically infinite, this is great progress. The principle for the various DCS systems are the same. Algorithms are usually called functional blocks. Functional block called the function block library assembly. DCS controller mainly by the CPU, ROM, RAM, E2PROM, address setting switches and other ponents. CPU plete the operation, ROM is used to keep the operating system, function block libraries, function blocks are arranged in the ROM is set in, the user can not be changed. RAM is used to save CPU putational results and I / O signals. E2PROM keep even with the function block into the control program. Under the power, the control program is not lost. Moreover, the control scheme not suitable, you can modify. Modify the use of ultraviolet radiation, to erase the contents of the E2PROM. Controller in the work should be address by the address switches to set. Function blocks are arrange