TERASHIMA Nobuhiko1 KAWASHIMA Tetsuya2 KAKIMOTO Mamoru2 TANAKA Mihoko2
The new CENTUM CS 3000 distributed control system for large-scale plants incorporates the new technologies of OPC, DCOM, ActiveX and Web browsers to offer interoperability through standard data access interfaces and component embedding technology. These new technologies are essential for the CENTUM CS 3000 as a platform to supply solutions.
- Process Information System Center
- Process Control System Center
|Figure 1 Conventional
In this day and age, just simply buying a personal computer, taking it home and turning it on will enable you to be taken to the world of Internet. In such an era, communication connection capability and prospects is increasing in importance. DCSs are no exception for concern. Advanced computerization is also required in manufacturing sites.
In a plant, a DCS is an intelligent piece of equipment that has control functions and works on the front line of a manufacturing site as well as acting as a centralized warehouse for storing manufacturing information. Although this information is important since production planning and scheduling, cost calculations, and business analyses are performed based on it, there has until recently been no general-purpose interface between a DCS and upper-level systems. The integration of a DCS with an MES and ERP has been difficult.
BACKGROUND OF INCORPORATION OF NEW TECHNOLOGIES
|Figure 2 Client/Server
Architecture using OPC
DCSs are required to be systems that can be integrated into a highly computerized society. Information exists in a DCS, MES, ERP, and elsewhere at different hierarchical levels and in different forms. In the time of computerization it is essential to have the capability to share internal and external data with different systems. In other words, open data interfaces are required.
In response to the focus on development towards open data interfaces, multiple new technologies have been incorporated into the CENTUM CS 3000. At the core of these technologies is OLE for Process Control (OPC). OPC is a standard specification of communication interfaces in the process automation (PA) and factory automation (FA) industries. Via an OPC interface, other vendors' DCSs and programmable logic controllers (PLCs) can be connected to a CENTUM CS 3000 system. The CENTUM CS 3000 uses OPC technology for the following functions:
- Embedding of ActiveX controls in graphic windows
- Display of graphic windows in a World Wide Web browser
The incorporation of these new technologies, has meant that the CENTUM CS 3000 meets the requirements of the times by offering a truly "open data interface" that allows the internal data of a DCS to be accessed from the outside as well as enabling a DCS to access data from outside of itself.
|Figure 3 Frow of ActiveX Controls Creation|
OPC is based on Distributed Component Object Model (DCOM) technology that was proposed by Microsoft Corporation for Windows-based networks, and is a specification that stipulates the communication interface for networking environments for PA and FA. Many DCS, PLC, Plant Information and Management (PIM), and Supervisory Control and Data Acquisition (SCADA) vendors are participating in activities to draw up OPC specifications. Yokogawa is also participating in Japanese domestic and overseas OPC workgroups.
Traditionally, DCS and PLC vendors prepared the vendors' original interfaces for upper-level systems. As shown in Figure 1, each client therefore needed to prepare a specific interface for each DCS and PLC. This troublesome necessity of multiple interfaces has had the effect of hampering the increase of mutual connections.
Figure 2 shows client/server architecture with the incorporation of OPC technology in DCSs and PLCs. In this architecture, each client is only required to have an OPC interface to access data in the DCSs and PLCs of all vendors via an OPC server inside each of the DCSs and PLCs. It is only natural, that such a simple requirement will help increase mutual connections and open systems.
OPC Server of CENTUM CS 3000
For the purpose of providing an open data interface as aforementioned, we have developed an OPC server that runs on a human interface station (HIS) of the CENTUM CS 3000 and conforms to OPC Specifications of the OPC Foundation, as shown in Tables 1 and 2.
Table 1 OPC Server Specifications of OPC Foundation
|DA2||OPC Data Access Specification 2.0|
|HA1||OPC Historical Data Access Specification 1.0|
|AE1||OPC Alarm & Event Specification 1.0|
The CENTUM CS 3000 supplies various process data to upper-level systems via the OPC server. To enable each client to access almost any kind of data in the CETUM CS 3000, custom interfaces are added to the interfaces defined in OPC Specifications, as shown in Table 2. We will propose to OPC workgroups that these custom interfaces be incorporated into standard interfaces in OPC Specifications.
Table 2 Compliance of CENTUM CS 3000's OPC Server
|Accessed Data||Access||Conforming to (Ref. Table 1)|
|Historical tread data||Read||HA1|
|List of trend data to be acquired||Read||HA1|
|List of data to be summarized||Read||HA1|
|Alarm event message notification||Read||AE1|
|Alarm event message generation||Read||Custom|
|Information of data of batch common data block||Read||Custom|
|List of information of data of batch common data block||Read||Custom|
|Figure 4 Data Flow|
In the CENTUM CS 3000, security settings have been enhanced to fill security holes that existed with the insufficient security provided with DCOM. This enables detailed security settings to be made for each client. For example, it is possible to permit only client A to write the SV of FIC100 and only client B to read the PV of TIC200.
For an OPC server in a DCS, care must be taken that the operation and monitoring functions are not affected by large amounts of data being accessed for reading and writing too frequently. CENTUM CS 3000's OPC server does not permit access for more than a specified amount of data within a specified time in order to limit the load on each HIS and field control station (FCS) and V-net communication load, thus assuring steady plant operation.
ACTIVEX CONTROLS AND CONTAINERS FOR GRAPHIC WINDOWS
|Figure 5 Example of System for Browsing HIS's
Graphic Windows via a Web Browser
Graphic windows of HIS are provided with extensive primitives to allow the building of operation and monitoring windows suitable for the needs of each user.
In OLE terminology, the word container means a file containing linked or embedded objects. As a new feature, ActiveX controls can be embedded in HIS graphic windows. (See Figure 3.) This feature, referred to as graphic container, offers the following advantages:
- Allows the user to add desired, specialized functionality to a graphic window
- Allows the user to create most animated graphic windows of rich representations
ActiveX controls can be written in a variety of programming languages, including C, C++, Visual Basic, and Java. For example, process data can be obtained via an OPC server and easily processed using an ActiveX control. Also, various forms of presentation including graph displays and DYNAMO-flow diagrams can be added to HIS graphic windows using ActiveX controls supplied from a third party. Since the properties of each ActiveX control can be set using the Graphic Builder, a user- created ActiveX control can be used in different windows for different projects by changing the properties.
Control for ActiveX Controls The graphic interface control enables the user to create ActiveX controls to be embedded in a graphic window. Using properties, methods, and events provided by the graphic interface control (part of these are shown in Table 3), the user can create ActiveX controls well fitted to HIS graphic windows.
Table 3 Properties, Methods, and Events Provided by Graphic Interface Control
|Properties||HIS station name|
|HIS window name|
|Keyboard-focus state of window|
|Request to the move the arrow-shaped cursor|
|Request to display a confirmation dialog box|
|Request to display an error message dialog box|
|Request to execute the function assigned to a function key|
|Request to change an LED status|
|Request to change the buzzer status|
|Request to read/write a graphic generic name|
|Event||Synchronization event of timing to draw blinking|
|Periodic event of a window|
|Move of the arrow-shaped cursor event|
|Function key event|
|Change of keyboard-focus status of window|
|Figure 6 Function Configuration|
The graphic interface control itself is also supplied as an ActiveX control and hence it can be used in Visual Basic and other programming languages just like other controls. When creating an ActiveX control, allot the icon of a graphic interface control object in a window, then read and write the properties, methods, and events of that object. This icon is invisible at runtime.
User-created ActiveX controls can also exchange data directly with a graphic window container; however, use of the graphic interface control has the following merits:
- Reduction of man-hours for creating ActiveX controls
- Support of debugging in Visual Basic
- Future expandability
In Visual Basic, the graphic interface control acts almost the same as it does during runtime. Hence, ActiveX controls can be debugged easily.
The graphic interface control and graphic window exchange data via the Component Object Model (COM) interfaces with each other in order to prevent the performance from being degraded when multiple ActiveX controls are embedded in a graphic window (see Figure 4).
DISPLAY OF GRAPHIC WINDOWS IN A WEB BROWSER
|Figure 7 Process Flow|
Software enabling CENTUM CS 3000's graphic windows to be displayed in a Web browser such as Internet Explorer and Netscape Navigator on a general-purpose personal computer has been developed. Traditionally, data and displays of a DCS were presented to the plant operators, but rarely disclosed to personnel in other departments. However now, there is the demand for a system solution of information sharing in a company, which allows, for example, access by management to data accumulated in a DCS. Using this software, CENTUM CS 3000's graphic windows can be browsed and viewed anytime anywhere via a Web browser.
- The only requirement is access to any type of PC that is capable of running a Web browser to display graphic windows.
- Effective use of the intranet (no need of new cabling)
- Integration of leading-edge Internet technologies with a DCS system
An example is given in Figure 5. A Web browser runs on client PCs and displays the HIS's graphic windows. Process data is collected from the HIS via the WWW server. Since client PCs do not directly access the HIS in this configuration, the safety integrity of the DCS system is secured.
Overview of Actions (See Figure 6)
Using this software, the user can view in any desired Web browser, almost the same windows as the CENTUM CS 3000's graphic windows. This is made possible by converting each graphic object file of the CENTUM CS 3000 into a Java applet.
- Drawing Primitives:
Each Java applet supports functions equivalent to those of the CENTUM CS's graphic windows.
- Data Acquisition:
Process data is collected via the Data Source Server running on the WWW server from an OPC server running on an HIS.
For security, it may be desired to permit only authorized users to access DCS's windows. In this case, security can be set for each Web page so that the graphic windows will only be displayed when a key-code floppy disk is inserted into the computer.
Process Flow (See Figure 7)
- Graphic Object Conversion:
- Converts graphic object files of the CENTUM CS 3000 into Java source files.
- Creates Java applets from converted Java source files using a Java compiler available on the market.
- Running Java Applet:
- Java applets draw graphic primitives and acquire process data. Since a user who views these Java applets does not actually operate the plant, Java applets perform data acquisition only when run and do not update the displayed data periodically. To display the updated data, the user must click the button designated by the Web browser. In Netscape Navigator this is the Reload button and in Internet Explorer this is the Update button.
- Graphic windows displayed in a Web browser are used only for monitoring and cannot be used for operation.
- Data Source Server:
- The Data Source Server is a server that interfaces Java applets with an OPC server by converting the OPC interface protocol to its unique TCP/IP socket interface protocol.
- The Data Source Server runs as a service under Windows NT.
In order to meet the needs of the times, we must pursue new technologies and incorporate them into the CENTUM series of core products wherever appropriate. By keeping our eyes on the development of new technologies we aim to continue introducing new attractive products in the future.
Furthermore, as a major DCS vendor, we are committed to using our extensive expertise in a positive way to help with the activities of stipulating OPC interface specifications.
- Windows, Windows NT, ActiveX, Visual Basic, C++, OLE, and Internet Explorer are registered trademarks of Microsoft Corporation, USA.
- Netscape is a registered trademark of Netscape Communications Corporation.
- Java is a registered trademark of Sun Microsystems, Inc.
- Other product and company names appearing in this report are trademarks or registered trademarks of their respective holders.
바이오매스는 최근 화력 발전소가 이산화탄소 배출량을 줄일 수 있는 재생 가능 에너지원이기 때문에 점점 더 이슈가 되고 있습니다. Yokogawa 시스템은 바이오매스를 사용하는 발전소를 포함하여 모든 유형의 발전소에서 전 세계적으로 사용되고 있습니다. Yokogawa의 측정 및 제어 기술을 통해 발전소는 보다 효율적으로 운전이 가능하며 탄소배출을 줄일 수 있습니다.
석유 화학 제품, 무기물 또는 중간체를 생산하든 관계없이 화학 회사는 안전하고 호환되는 작업을 유지하면서 적시에 효율적인 방법으로 제품을 제공하는 비용과 마진 압박에 시달리고 있습니다. 또한 화학 회사들은 공급 원료 및 에너지 가격의 변동에 적응하고 가장 수익성 높은 제품 혼합을 시장에 제공해야 합니다.
Yokogawa는 벌크 화학 시장의 자동화 요구 사항을 세계적으로 지원해 왔으며 이 시장에서 인정받는 선두 주자입니다. Yokogawa는 제품, 솔루션 및 업계 전문 기술을 통해 시장 및 생산 요구 사항을 이해하고 플랜트의 수명주기를 통해 안정적이고 비용 효율적인 솔루션을 제공하기 위해 협력합니다.
1970년대 중반, Yokogawa는 EBS 전기 제어 시스템 (EBS Electric Control System)의 출시와 함께 전력 사업에 진출했습니다. 그 이후로 Yokogawa는 전 세계 고객에게 최상의 서비스와 솔루션을 제공하기 위한 기술과 역량의 개발을 꾸준히 지속해 왔습니다.
Yokogawa는 역동적인 글로벌 전력 시장에서 더욱 적극적인 역할을 수행하기 위해 글로벌 전력 솔루션 네트워크를 운영했습니다. 이로 인해 Yokogawa 내에서 보다 긴밀한 팀워크가 가능해져서 글로벌 리소스와 업계 노하우를 하나로 모았습니다. Yokogawa의 전력 산업 전문가들은 각 고객에게 정교한 요구 사항에 가장 적합한 솔루션을 제공하기 위해 협력합니다.
Yokogawa는 보다 효율적인 사회를 만들기 위하여 에너지 최적화 기술 개발, 온실가스 감축, 오염 물질로부터 환경을 보호하는 견고한 제품 제작 등을 통해 지속 가능한 수자원 생산을 위한 제어 솔루션을 제공하고 있습니다. Yokogawa의 첨단 기술과 폭넓은 애플리케이션 노하우를 통해 고객과 협력하여 사업을 활성화하고 플랜트 수명주기 전반에 걸쳐 높은 가치를 제공할 수 있는 지속 가능한 솔루션을 제공합니다. 당사의 기술과 제품은 플랜트의 성능을 향상시키고 오늘날의 수자원 시장에서 경쟁적으로 운영할 수 있도록 보장하며 운영비를 절감합니다. Yokogawa는 지자체 및 공업용수 처리 시장에서 광범위한 수처리 응용 분야를 지원합니다.
지열에너지는 기상 조건에 의존하지 않기 때문에 일 년 내내 안정적인 전력을 공급할 수 있습니다. 또한 어떤 연료도 지상에서 태우지 않으며 매우 적은 양의 이산화탄소만 배출되므로 환경친화적입니다. 태평양, 일본, 필리핀, 인도네시아, 뉴질랜드, 멕시코, 코스타리카, 미국 등의 국가에서 태평양 연안 벨트 ("불의 고리"라고도 함)를 따라 풍부한 지열 자원이 있습니다. 다른 지열 활동 지역에 위치한 아이슬란드, 터키 및 이탈리아와 같은 국가들과 협력합니다. Yokogawa는 현재까지 일본, 동남아시아 및 기타 지역의 30개 지열발전 프로젝트를 실행한 경험을 바탕으로 지열발전 시스템의 신뢰성 및 유지 관리 효율성을 향상시키는 다양한 측정 및 제어 기술을 제공하고 있습니다.