The ARC consultation organization in 2003 has issued the world DCS market forecast report. This report forecast, the world DCS market will maintain 2.5% growths from 2002 to 2007, will grow from 2003 9.1 billion US dollars to 10.3 billion US dollars. The DCS development speed therefore is not high, the main reason is US and so on the developed country economy rate of rise reduces speed creates. But the Chinese in recent years DCS rate of rise should above 10%. Now DCS compared with ten year ago DCS, has had the fundamental change.

DCS already entered the fourth generation

The information technology (network communication, computer hardware technology, is inserted the influence which type system technology, field bus technology, each kind of configuration software technology, data bank technology and so on) develops, as well as the user to the advanced control function and the management function demand increase, each DCS merchant (take Honeywell, Emerson, Foxboro, horizontal river, ABB as represents) promotes the DCS system in abundance the technical level, and unceasingly enriches its content. It can be said that, take Honeywell Corporation newest promoted Experion PKS (process knowledge system), Emerson Corporation's PlantWeb (Emerson Process Management), Foxboro Corporation's A2, horizontal river company's R3 (PRM- factory resource management system) and ABB Corporation's Industrial the IT system already formed as symbol new generation of DCS.

If we regarded as same year Foxboro Corporation's I/A Series the third generation DCS system milestone, then above several newest DCS was allowed to divide into the fourth generation. The fourth generation of DCS most main symbol is two "I" the opening word: Information (information) and Integration (integration).

Fourth generation of DCS technical characteristic

The fourth generation of DCS system structure mainly divides into four structures: Scene meter surface layer, control device unit level, factory (workshop) level and business management level. The general DCS merchant mainly provides except the business management level outside three functions, but the business management level through provides the opening the database interface, the connection third party management software platform (ERP, CRM, SCM and so on). Therefore, now DCS mainly provides the factory (workshop) level all controls and the management function, the sum aggregate helps the enterprise the information management function.

DCS fully manifests the information and the integration

The information and the integration basically described now the DCS system the change which occurs. The user already was allowed to gather entire factory workshop and the process information data, but the user hoped these massive data could manifest by the appropriate way, and the help decision-making process, let the user by his clear way, obtained the true need in the convenient place the data.

The information manifested in each DCS system already was not a control function primarily control system, but was a full display information management function comprehensive platform system. DCS has provided from the scene to the equipment, from equipment to workshop, from workshop to factory, from factory to enterprise group entire information channel. These information have fully manifested comprehensive, the accuracy, timeliness and the systematic characteristic.

Majority of DCS has provided the conventional DCS function, SCADA (monitoring and data acquisition) the function as well as MES (manufacture execution system) majority of functions. Is different with ERP, M E S collected in the workshop to use to manage and the optimization, moves the entire process from the under order form to the finished product production the related hardware or the software module, it controlled and uses the real-time accurate manufacture information to instruct, the instruction, to respond and to report the workshop occurred each activity, simultaneously provided the related production activity to the enterprise decision-making support process the duty appraisal information. The M E S function including function model and so on the workshop resource distribution, process management, quality control, maintenance management, data acquisition, performance analysis and material management, has the resources disposition and the condition with the DCS correlation various functions module (Resource Allocation and Status), the dispatch production unit (Dispatching Production Units), the documents control (Document Control), the data collection/gain (Data Collection/Acquisition), the labor management (Labor Management), the quality control (Quality Management), the maintenance management (Maintenance Management), the product track (Product Tracking), the performance analysis (Performance Analysis).

The DCS integration manifests in two aspects: Function integration and product integration. The past DCS merchant basically is by the independent development primarily, provided the system also was own system. The now DCS merchant emphasized the system integration and the plan ability, in DCS outside the process control function which realizes except retention tradition DCS, but also integrated PLC (programmable logical controller), RTU (has gathered transmitter), FCS, each kind of return routes regulator, each kind of intelligent gathering or the control unit and so on. In addition, each DCS merchant no longer or makes development configuration software each kind of hardware unit to regard as the core technology, but is uses in abundance the DCS each constituent the third party integration way or the OEM way. For example, most DCS merchant no longer develop the configuration software platform, but changes over to uses brothers the company (for example Foxboro with Wonderware software for foundation) the general configuration software platform, or other companies provide the software platform (Emerson is used as basis with the Intellution software platform). In addition, many DCS the factory even I/O module also selects the OEM method (Foxboro to use Eurothem the I/O module, horizontal river R3 uses the Fuji electrical machinery Processio to take the I/O unit foundation, Honeywell Corporation's PKS system uses Rockweell Corporation the PLC unit to take the scene control station.

DCS turns the true mixture control system

In the past DCS and PLC through are mainly controlled the object the characteristic (process control and logical control) carries on the division. But, fourth generation of DCS already fuzzily melted this kind of division. Nearly all fourth generation of DCS all contained the process control, the logical control and the batch run control, the realization mixture control. This also is for adapt user's true control demand. Because the most industrial enterprise cannot simply divide into the sole process control and the logical control demand, but is primarily or the logical control primarily minute process is composed by the process control. We must realize the entire production process optimization, enhances the entire factory the efficiency, must bring into line with the entire production process the unification the distributional integration information system. For example, the typical metallurgy system, the papermaking process, the cement production process, the drugs manufacture production process and the food processing process, the electricity generation process, the majority of chemical industry production process all is by the partial continuously regulating control and the partial logical interconnection control constitution.

The fourth generation of DCS system nearly completely uses the IEC61131-3 standard to carry on the configuration software design. This standard originally is a standard which the PLC language design provides. Simultaneously some DCS (for example Honeywell Corporation's PKS) also directly uses mature PLC to take the control station. Most fourth generation of DCS all may integrate middle and small scale PLC to take the first floor control unit. Today small and miniature PLC not only has had the large-scale PLC all basic logic operation function, moreover high-level operates, the correspondence as well as the movement control also can realize.

DCS contains the FCS function and further disperses

In the past period of time, some scholars and the merchant considered as contradictory DCS and FCS. Actually, truly impelled FCS to progress still was the world main several DCS merchant. Therefore, DCS cannot replace by FCS, but is DCS can contain FCS, realizes true DCS. Now, this forecast is being confirmed by the reality. All fourth generation of DCS has all contained each kind of form field bus connection, may support the many kinds of standards the field bus measuring appliance, the implementing agency and so on. In addition, each DCS also changed the original cabinet posture to install the I/O module, the relative centralism control station structure, displaces I/O module which was further disperses (guide rail installment), either the miniaturized I/O module (was allowed scene installment) or middle and small scale PLC.

A distributional control important merit is the logical division, engineer may conveniently assign the different equipment control function according to the equipment to the different appropriate control unit on, such operator may according to need to carry on modular to the individually control unit the function to revise, to take off costume with the debugging. Another merit is, each control unit distribution installs in is controlled nearby the equipment, both saves the electric cable, and may enhance this equipment the control speed. Some DCS also will include distributional HMI to operate the station, the person and the machine organically fuses in together, together will complete a intellectualized factory each kind of operation. For example Emerson DeltaV, in Foxboro A2 small modular structure, Ovation dispersible modular structure and so on.

It can be said that, the present DCS merchant already crossed 炒作 the concept the erroneous zone, but was the prominent usability. Set of DCS may adapt the many kinds of scenes to install the pattern: Either with field bus intelligence measuring appliance, either uses the scene I/O intelligence module to install (both saves signal electric cable, and does not use expensive intelligent measuring appliance), either uses the cabinet type centralism installment (specially to suit transforms scene). All decided by user's field condition that, fully manifests for the user tentative plan.

DCS enters the low cost time

DCS in on century 80's 90's or the technical content high, the application relatively is even complex, the price also quite expensive industry control system. Along with the application popularization, everybody to the information technology understanding, DCS already went out the noble mystical tower, turned everybody to be familiar with, the price reasonable convention control product.

The fourth generation of DCS another remarkable characteristic is various systems uses the ready-made software technology and the hardware in abundance (the I/O processing) the technology, uses the nimble scale disposition, obviously reduced the system the cost and the price. It can be said that, now uses advanced DCS to realize the industrial automation control compared to originally to use conventional the instrument measuring appliance to carry on the simple control, the user investment increases are not many, but realizes the function actually obviously strengthens. Speaking of the control station, original physics signal processing average 1,500 Yuan (Renminbi), but now already fell to 800 Yuan about. In the past overseas DCS generally only suited to the large and middle scale systems application, in small application cost very high, but fourth generation of DCS all used the nimble disposition, not only economically applied to the large and middle scale systems, moreover applied to the small system very is also appropriate.

DCS platform opening and service specialization

For 20 years, a field discussion extremely many concept is an openness. In the past, as a result of communication relative backwardness, openness was puzzles the user an important question. In order to solve this problem, the people have conceived the many kinds of plans, including CIMS system concept in open network (MAP 7 networks agreements platform). However, the MAP network agreement has not certainly obtained the true promoted application. But the contemporary network technology, the data bank technology, the software technology, the field bus technology development has provided the possibility for the opening system. Each DCS factory competition intensifying, promoted the thin division of labor and the cooperation, various factories gave up the working pattern which original own independently develops, turns integrated and the cooperation development pattern, therefore openness automatically realized.

Fourth generation of DCS openness

Openness manifests in DCS may mutually connects from three different stratification planes and the third party product: Supports each kind of management software platform connection in the business management level; In the factory vehicle intercalated bed support third party advanced control product SCADA platform, the MES product, BATCH processing software, simultaneously supports the many kinds of networks agreement (by ethernet primarily); May support the many kinds of DCS unit in the installment control level (system), PLC, RTU, each kind of intelligence control unit and so on, as well as each kind of standard field bus measuring appliance and implementing agency.

Openness indeed has very many advantage, but during consideration open, first must fully consider the system the security and the reliability. Because the production process breakdown stops the loss which or the accident creates, possibly the cost which saves the open choice product must be much higher than. Also pays attention, when selective system equipment, first must determine the system the demand, then basis demand choice essential equipment. Do not have to equip some nonessential function as far as possible, specially the network function nf and outside supposes the choice certainly must be prudent. For example, we during choice opening network, encounter the virus or the hacker attack possibly can enlarge; We choose the rich outside 设如 light to drive or softly to drive, gives the operator has provided loading irrelevant software (for example game and so on) the opportunity and so on. These can cause the system paralysis or other fatal breakdowns.

Along with opening system and platform technology development, product choice more nimble, the software configuration function more and more formidable and is flexible, but each specific application all needs a unique solution, therefore the specialized application knowledge and the experience are the key aspect which now the industrial automation merchant or system integration business succeeds. Each DCS factory while diligently is propagandizing respective DCS technology superiority, is diligently propagandizes own profession plan design and the executive ability. Provides specialized for the different user the solution and the implementation specialization service, will be the next each DCS factory and the system integration business competition focal point, simultaneously also is various factories profit main origin.

Domestically produced DCS technology application survey

At present, by with advantage when, Zhejiang major and medium control, the Shanghai New China passes through 10 years endeavor for representative's domestic DCS factory, respectively promotes own DCS system: With advantage when promotes MACS - Smartpro major and medium the fourth generation of DCS system, Zhejiang controls promotes Webfield (ECS) the system, New China promotes the XDPF-400 system. Three great efforts, through compete successfully apply the independent system to each industry scene, gradually is obtaining the user the approval. For example the New China company obtains the remarkable result in the thermoelectricity generation aspect, Zhejiang major and medium controls in aspect achievement and so on chemical control is prominent, with advantage when the company in nuclear aspect and so on electricity, thermoelectricity, chemical industry, cement, drugs manufacture as well as papermaking has obtained the certain achievement.

In China's DCS market, three domestic merchants have already had the suitable competitive ability. For example through New China company with with advantage when company when thermoelectric power station control domain competition as well as with advantage the company and Zhejiang major and medium control in domain the and so on chemical industry competition, causes overseas DCS to reduce prices in abundance. It can be said that, three companies biggest contributions were fall original the overseas DCS price below 40%, was DCS in the home industry enterprise's popularization application, specially has made the contribution in small and medium-sized enterprise's application.

Process control system development course

50 years ago, the process control is based on 3 ~ 15psi air operated signal standard base type pneumatic control measuring appliance system, namely first generation of process control system structure (PCS, Pneumatic Control System); Based on simulation electric current signal standard 0 ~ 10mA (4 ~ 20 mA) electrically operated unit combined type simulation measuring appliance control system, namely for second-generation process control system structure (ACS, Analogous Control System); 20th century 70's, because has used the digital computer, thus has produced the central numerical control system, namely third generation process control system structure (CCS, Computer Control System); 1980s, microprocessor appearance and application, thus has produced the distributional control system, namely fourth generation of process control system structure (DCS, Distributed Control System); The 1990s, the field bus technology appearance has had the new generation of process control system structure, namely field bus control system FCS (Fieldbus Control System)

Field bus control system superiority

The field bus is called the 21st century commercial run observation and control network standard. It can provide intellectualized, the simplification, the standardized field bus equipment connection, will cause the process control user at the low cost, to be easy to transplant, is easy to expand in this kind of kind of friendly environment to carry on the system design, the installment and the movement, has brought the new revolution for the automated domain, has the widespread application domain and the market.

The field bus product is uses in the correspondence network product which the process automation and the manufacture automation lowest level scene equipment or the scene measuring appliance interconnects, is the scene correspondence network and the control system integration. Its key not merely only one kind of communication, but is (FCS) replaces the distributional control system with the field bus control system (DCS).

Compares with DCS, FCS has the many kinds of superiority: Saves the electric cable and the electric cable bridge approximately 60%, saves the workshop area; The reduced wiring, installs the debugging expense above 50%; Saves two times of development costs, reduces the development cycle, the disposable investment may reduce 30%; The spare parts spare parts type obviously reduces, the service is more convenient; Is advantageous implements the synthesis automation strategy to the enterprise, causes the enterprise from to be extensive to the intensive transformation.

Since the the end of 1980s, some several kind of field bus technology already gradually has developed maturely, and had demonstrated in some specific application domains the influence and the superiority, they were addressable long-distance converter data link HART (Highway Addressable Remote Transducer), controller partial net CAN (Controller Area Network), partial operation network LON (Local Operating Network), process field bus PROFIBUS (Process Fieldbus) and foundation field bus FF (Foundation Fieldbus), these field bus each characteristics, are playing the vital role regarding the field bus technology development.