Abstract: Early DCS is completely closed, by the various production plants produce their own I / O components, controllers, operator stations, engineering stations, their networks and systems design and development control configuration software. Users of any link can not exist without the DCS manufacturing plant, everywhere bound by. In other words, all DCS plant hardware (including I / O components, controllers, operator stations, engineering stations) can not substitute one another, the system network incompatibility, can not exchange information, control configuration software, a wide range of … &hellip ;
Keywords: PLC IEC1131-3 standard DCS
DCS is a completely closed early by the various production plants produce their own I / O components, controllers, operator stations, engineering stations, designed and developed their own network and control system configuration software. Users of any link can not exist without the DCS manufacturing plant, everywhere bound by. That is, each DCS plant hardware (including I / O components, controllers, operator stations, engineering stations) can not be another alternative, the system networks are not compatible and can not exchange information, control a wide range of configuration software. Even with multiple cross-DCS plant instrumentation company, its subsidiary the DCS plant products such circumstances, such as ABB, its subsidiary DCS with Bailey (Bailey) Company INFI-90, A Xiya (Asea) Company MASTER, Hartmann · Brown (Hartmann & Braun) company Freelance 2000.
In recent years, this situation has changed, the operator station, station engineers can use general-purpose computer; all manufacturers have to give up their own system of networking to adopt a common computer network; when the DCS into the field bus technology, with I / O components may choose. The only configuration has not changed is the control software. General control configuration software each other so that each user when using a new software to re-learn, factory control configuration software for a lot of manpower and material resources.
DCS PLC do it in front as early as 198C can use the same project in multiple programming languages, nested within each other for the user to choose the most simple way to generate control strategies.
IEC1131-3 standard is announced, has introduced a number of PLC manufacturers meet this standard PLC products. American AB company belongs to Rockwell (Rockwell) company, with many of its PLC products meet IEC1131-3 standard, structured text software options. French Schneider (Schneider) Modicon TSX Quantum PLC company products comply with IEC1131-3 standard can be used Concept package, it supports the Modicon 984 ladder, but also follow the IEC1131-3 standard five kinds of programming languages. Germany s Siemens (Siemens) Company SIMATIC S7-300, S7-400, C7-620 are used SIMATIC software packages, including some ladder line with IEC1131-3 standard and optional software S7-SCL (Structural Control Language) can be calculated and simplify complex algorithm such as data processing operations, and the other optional software S7-GRAPH (standard display) with a variety of conditions can be converted to complete complex sequence control. According to reports, the equivalent of two optional software IEC1131-3 standard, structured text and sequential function chart. For the convenience of users, they can also provide the conversion software to Siemens AG (merger of its products including the former Texas Instruments Inc. PLC) previously used STEP5/TISOFT programs into SIMATIC S7 system. Beckhoff (Backhoff) Company WinCAT PLC Control system uses the T WinCAT industrial control software, which supports all 5 standard IEC1131-3 languages. Taiwan s Advantech ADAM-5510/P31 set by the Beijing-controlled company s distribution STAR P31 PLC products are used Paradym-31 package, which contains the provisions of IEC1131-3 standard sequential function chart, ladder and function block diagram 3 language.
2 DCS possibility of using IEC1131-3 standard worked Honeywell (Honeywell) companies, ABB Bailey, Westinghouse (Westinghouse), Rockwell Software provides control of a U.S. company, recently launched with a PLC form M process control system, but users on the M system meets IEC1131-3 standard issue questions, the publicSaid: “ IEC1131-3 standard PLC system developed specifically for its purpose is to provide a benchmark for developing logic controller, using the same procedure is the same programming tools), including technical standards, many of these requirements do not apply process control system, M systems and process control system DCS, like many, found IEC1131-3 standard does not apply to process control ”.
Perhaps worried that affect product control software on the market sales of this seems somewhat one-sided view. In fact now been simple logic controller PLC, and many have already learned a DCS PLC product strengths, and the mutual penetration and integration of the DCS; are DCS conventional PID control, advanced loop control, complex math functions such as PLC products have been commonplace ; DCS to completion, should be said that the basic PLC system can be completed. Many scholars believe that the realization of DCS and PLC functionality closer, the difference will gradually disappear. PLC system can be completed using IEC1131-3 standard control software configuration work, DCS with the standard control software should be able to complete the configuration work.
Specifically, DCS control configuration software features include switch quantity involved in the logic control, analog PID control and complexity of these three categories math functions. Using ladder, sequential function chart, instruction sheet and other programming languages to complete the logical volume control switch is self-evident; function block diagram using simple PID, advanced loop control is possible, more complex loop control can be achieved through structured text; loop control with the same math, but also with function block diagram and structured text language. More complex requirements in the present DCS is also using some special equipment, special configuration mode to be addressed, such as Honeywell TDC-3000 system, application components can be used to calculate CL units and specialized high-level control language to complete the work.
3 IEC1131-3 standard0 domestic DCS products are not lagging behind in this respect, the first introduction of IEC1131-3 standard metallurgical equipment by the Department of Intelligent Automation Research Institute, which produced EIC2000 fieldbus control system used in the standard. If EIC2000-LON subsystem contains OnLon software and EIC2000-ST Workbench software subsystem includes all the ISaGRAF software support. Beijing and Lee earlier when the company recognizes the importance of IEC1131-3 standard, they HS2000 DCS has been used on a ladder, function block diagram and structure of the text in standard language, introduced in 1999 FOCS Fieldbus control with advanced control systems and MACS system, using IEC1131-3 standards for all five kinds of programming languages. The outstanding performance of the power industry, Shanghai Xin Hua Control Engineering Company XDPS-400 DCS, the control configuration software with the IEC1131-3 standard function block diagram programming language. Application of the chemical industry of Zhejiang many of its new VIA Automation support fieldbus FB-3000 DCS in compliance with the IEC1131-3 standard control configuration software. China has reached 500 sets of DCS application in Zhejiang Highne Control Automation Co., Ltd., its new system JX-300X also supports the IEC1131-3 standard ladder diagram, function block diagrams and sequential function chart. June 2000, Shenzhen De Weisen flexible control system TCS launched its control configuration software TP311, TP321 used in the IEC1131-3 standard package.
Our engineering practice for the material composition of the material blending HS2000 DCS control software configuration, use the ladder, function block diagram and structured text and other programming languages, especially with the structure of the text on the analysis of X fluorescence analyzer ratio of complex algorithms for material control configuration and found that function quite powerful and did not produce IEC1131-3 standard is not suitable for process control of any feeling.
In summary, using IEC1131-3 standard programming language to facilitate practical, high standardization, users can be familiar with the configuration work quickly and to the original for the new system to acquire knowledge; to the manufacturer, this may be the humanResources invested in DCS hardware, network or otherwise. From this, DCS control configuration software using IEC1131-3 standard should be the development of DCS.