International Carpathian Control Conference ICCC 2002 MALENOVICE, CZECH REPUBLIC May 27-30, 2002 PROCESS DATA VISUALIZATION AND MONITORING USING INTERNET Lenka LANDRYOVÁ 1 and Jiří KOZIOREK 2 1 Department of Control Systems and Instrumentation, Faculty of Mechanical Engineering 2 Dept. of Measurement and Control, F. of Electrical Engineering and Computer Science VSB - Technical University of Ostrava, Ostrava, Czech Republic, lenka.landryova@vsb.cz, jiri.koziorek@vsb.cz Abstract: The paper gives main information about using information technologies in a control system. The term of information technology is being defined according to fundamental requirements coming from the everyday operation of a company. There is also a review of the recent state of the art of process data visualization and monitoring in industrial control systems. The paper refers to using information technologies at the lowest level of control applications in direct control. Then, it further describes the reasons for using Intranet/Internet in HMI/SCADA systems and explains thin and fat client functions. This work has been supported by MSMT 272300012 granted project. Key words: programmable controllers, HMI/SCADA systems, Internet, information. 1 Introduction Information technology - abbreviated as IT - is encountered nowadays in almost all branches of a company. The use of information technology in commercial application systems, i.e. in the office, can certainly be considered as normal. The ever-growing variety of new information technology has recently also resulted in the increased use in automation technology. Information (data) and efficient recording, distribution and processing are important factors contributing to the success of every company just like the machines and systems used for production. In the sales department, information is kept according to customers demand and purchasing conditions. In the accounting department, this information is used to calculate the prices for individual products as required by the marketing and order processing departments and then is supplemented by customer/order-specific data. The productionplanning department generates the appropriate production orders from this information. 721
In the production department, this information is supplemented and passed on to the distribution and order processing departments. The simplified information sequence presented here is closely associated with the material flow within the company, and especially the company turnover and success. As shown by this simplified consideration of the information flow in a company (Fig.1), it is initially necessary to record the information in some form, distribute it and then display or process it at the end. It is irrelevant whether the application is in an office or implemented into automation technology. Based on this consideration, it is possible to give the following definition for information technology: "Information technology covers the technologies for recording and conditioning, transmitting and distributing, using and processing information." A network is the basis enabling information technology to function in an office and for automation technology. The network provides the connections for integration of all participating systems, with active components such as switches and routers for Ethernet, FDDI or ATM, and passive components such as fiber-optic and copper cables with appropriate systems for structured cabling. Figure 1. Production phases [Siemens] Communication is based on open solutions that are on internationally standardized protocols, and is carried out on broadband networks, which also permit multimedia communication. 2 Requirements for Process Data Access Modern control systems for industrial applications acquire and work with a large amount of processed data. A lot of workmen need to use these data, but their requirements for frequency, speed and quality of access are different. One group of workers can be called operators. They need permanent access to process data and they must have a continuous view of controlled technology and the states of production facilities. They must also have possibilities of instantaneous intervention to controlled process. The above-mentioned requirements can be only met by advanced products of HMI/SCADA (Human Machine Interface/Supervisory Control and Data Acquisition) systems. These systems are developed for data acquisition, visualization and supervisory control of technological processes. 722
The other groups of workers are technologists, quality managers, stock holding owners etc. These workers usually don t need to have an instant access to a controlled technology. Access speed is not as critical for them. They are only occasional users, who need historical and statistical data more than actual process data. Using HMI/SCADA systems for all these workers is of a needless comfort. There is a special group of the process data users. There are mobile workers (such as managers or salesmen). They require data access from anywhere via World Wide Web Internet, or respectively via GSM. Their frequent requirement is, for example, setting up or canceling of a job order, or finding out the state of a concrete job. For designers or system integrators of control systems it is also very useful to be able to view the state of a system directly from their office. Connecting to a control system and viewing its state from a remote location can be helpful in many cases for example, a programmer can verify an operation of a control system without the necessity to go directly to a process line, or he/she can be prepared to solve any problems during the operation before he/she goes to the process with the possibility of doing simulation. Using present features of information technology could solve all the above-mentioned. There is a great demand for distributing applications using the Intranet/Internet, electronic mail or GSM in recent control systems. An increasing use of the Industrial Ethernet Network at the lowest level in control systems also helps to fulfill these requirements. 3 IT in a Direct Control Nowadays, it is often necessary to provide data directly from a low-level control to the Intranet/Internet. It could be for the reason of viewing the control system status or due to monitoring data. It is also possible to create the HTML visualization. The universal tool for solving this demand is Industrial Ethernet with Fast Ethernet (IEEE 802.3u) and switching technology. The Industrial Ethernet has following features: An area and cell network are complying with the IEEE 802.3 (Ethernet) international standard designed for industrial applications; Automation systems are being linked to each other and to PCs and workstations with means for homogeneous and heterogeneous communication; Extensive open network solutions can be implemented; High speed communication is being performed; Industrial Ethernet is an industrial standard proven and accepted worldwide; Provides a base for information technology in automation; Solutions, such as Web function, e-mail function and WAN links, are given; Designs suit the industry; Some of the above mentioned features has been tested during working out the paper, as the next part of this contribution will show. 4 IT in Siemens Control Systems SIMATIC NET from Siemens offers integrated industrial communication from the control level right down to the field level. A compliance with the major industrial standards makes this system open at all levels. Products developed for information technology by Siemens are called ITlution. Basic products of ITlution in a direct control are communication modules for Industrial Ethernet marked with IT. For example, the communication module CP 343-1 IT for Siemens Simatic S7 300; it has its own processor, 723
it relieves the CPU from communications tasks and facilitates additional connections. S7-300 with CP 343-1 IT has following communication options: Programming devices, processors, HMI devices; Other SIMATIC S7 systems; SIMATIC S5 PLCs; Integration into the information technology (IT) with e-mail and Web browser. The CP 343-1 IT (Fig. 2) can also accommodate a machine documentation or user guides, and others in its file system in addition to HTML pages. The authors tested CP 343-1 IT communication module and created a demonstration application. The module (Fig.3) enables visualizing data in HTML pages it can be displayed with a common Internet browser (MS IE). The module also enables changing data, monitoring the status of a PLC, it has the user security system. Figure 2. Distribution of a control application using IT communication modules [Siemens] Figure 3. Example of a user HTML page in CP 343-1 IT 5 Intranet/Internet in HMI/SCADA Applications The need for visualization of technological processes led to a development of SCADA/HMI systems. These are systems for designing and operating visualization, measurement, control and communication programs as well as for data acquisition, their historical logging and processing. They can be especially found in heavy industry, food processing and laboratories. Programs enable data transfer using protocols supporting other environments of applications. By DDE or Suite Link the visualization systems can be configured to use further data processing from a control process saved in other Windows 724
based applications (Excel, Access, Matlab). The visualization system does not only provide information for human-machine interface, but fulfills especially communication functions. All SCADA/HMI products are more or less comparable in a way for application design and their operation. The departments of the authors of this paper enable design, testing and verification of applications in several SCADA/HMI environments at the same time. As an example, the Factory Suite 2000 of Wonderware Co. and Factory Link 7 of USDATA could be given. FactorySuite Web Server enables Intouch Internet clients to access from remote locations to data from applications, which are installed with FactorySuite Web Server at the same local area network (LAN). It creates, in this way, an administration center and data gate for process and production information provided for operators, process engineers and maintenance workers, who require identical and by HMI visualized information (Fig,4). It also serves managers, who via Internet require a summary type of information from a production. Figure 4. The scheme of providing data by SCADA/HMI system, (a)sytem Factory Suite 2000 configuration and (b)www portal for a client station It has been verified, that FactorySuite Web Server optimizes requirements from clients, puts them into a queue and excludes multiple requests, so from the point of view of the data provider, more clients accessing the server at the same time appear as the only client. For 26 clients connected throughout a 56Kb/s connection, and for one screen containing 100 I/O variables, with 16 Internet routers and a FS Web Server connected via ISDN with a 115Kb/s capacity, the update of all variables at all client applications took 2-3s. The above mentioned tasks verified monitoring and visualization functions, their advantages and disadvantages for individual cases (Fig.5), when there will be required: Very powerful and optimized solutions, which substantively extend access to required production data for only authorized users connected to the Internet/Intranet from any place worldwide, Simple and fast solutions, which do not require means of a great cost for achieving the required level of data acquisition and their visualization from remote technological processes. 725
Conclusions The paper describes control systems, which are connected to and able to use Internet for different levels of technological process control. It demonstrates possibilities and advantages of direct control using PLC as well as visualization tasks and user interface for operator control from SCADA level by thin and fat client connection to Internet. Applications were designed as data providers from PCs at the computer lab of the authors department. These applications serve as demo applications to present possibilities of the Factory Suite Web Server to provide data from more source application to different clients. Figure 5. The configuration of verified monitoring tasks of remote technological processes Client access has been verified to the server as a fat client with full InTouch FS2000 installation, and as a thin client with visualization of the source application into MS Internet Explorer within the LAN network. One source application has been also run at the computer lab from another faculty and the client access has been tested for both thin and fat client with the data transfer from a remote LAN network. Monitoring remote technological processes has been also verified by other means-by running an application downloaded through Internet/Intranet and installed into a local disk of a client PC in WindowViewer environment by using View -i command from MS-DOS, then the text report has been generated as a very simple text message visualized on the screen, giving chosen numerical data on line. References ZOLOTOVÁ, I.-OCELÍKOVÁ, E.-BÁZLER, M.: Component Technology and Remote Visualization, In Proceedings Volume from the IFAC Conference, Control Systems Design, CSD 2000, pp. 595-600, June 18-20, 2000, Bratislava, Pergamon - Elsevier Science, ISBN 0-08-043546-7. ČERVENKA, Z. (2001): Using thin clients in industrial automation. In Pragoregula 2001. Praha. www.siemens.com: Siemens company web site 726