OLE For Process Control Research Articles

Component-based design for SCADA architecture

Supervisory control and data acquisition (SCADA) software which is suitable to distributed control systems is a demand for system developers because the characteristics of existing SCADA software packages are hard to satisfy the requirements of distributed systems. For the strengths of component-oriented techniques, this paper proposes a component-oriented architecture of SCADA software to satisfy the demand of distributed control systems. Design pattern and OPC (OLE for Process Control) technology are also used to make the openness for the architecture.

Integration of Process Simulators in Advanced Process Control Solutions

This paper presents a novel approach to test and to pretune advanced controllers to reduce the onsite work of control engineers and to train operators using advanced control solutions. Following the proposed approach a simulation framework has been developed where detailed process model realized in Matlab which is connected via OPC (Object-Linking and Embedding for Process Control) to the Profit Controller of Honeywell. With the application of the resulted simulation system the model predictive control (MPC) of a nonlinear crystallizer has been analysed. The case study demonstrates the efficiency of the proposed approach and the illustrative results show that the linear and robust MPC is an adequate controller of nonlinear crystallizers.

Design and implement of redundant OPC data acquisition system

To improve the system availability, a software-based OLE for Process Control (OPC) redundant data acquisition system was designed and developed. The hot spare redundancy system used two OPC servers; it can switch fast, has no disturbance and is easily applicable.

New Control System Aspects for Supporting Complex Data and High Performance System

The data in automation and control systems can be achieved not only from different field devices but also from different OPC (OLE for Process Control) servers. However, current OPC clients can only read and decode the simple data from OPC servers. They will have some problems to acquire structured data and exchange the structured data. In addition to the large network control systems, the OPC clients can read, write, and subscribe to thousands of data points from/to OPC servers. Due to that, the most important factor for building a high performance and scalable industrial control system is the ability to transfer the process data between server and client in the most efficient and fastest way. In order to solve these problems, we propose a means to implement the OPC DA (Data Access) server supporting the OPC complex data, so that the OPC DA clients are able to read and decode any type of data from OPC servers. We also propose a method for caching the process data in large industrial control systems to overcome the limitation of performance of the pure OPC DA system. The performance analysis and discussion indicate that the proposed system has an acceptable performance and is feasible in order for applying to real-time industrial systems today.

Development of remote control and monitoring of web-based distributed OPC system

This paper focuses on implementing remote control and monitoring of a web-based distributed OLE for Process Control (OPC) system. Remote monitoring and control of OPC-based systems realized at N different local control points on the Internet are achieved by using a distributed OPC (DOPC) architecture. In this proposed architecture, every local control center can control and monitor every other control point. DOPC architecture is developed by using an OPC standard created for the automation industry. This OPC was developed as an industrial standard using Microsoft's Object Linking and Embedding (OLE) technology. OPC enables different control devices to communicate with each other by exchanging data. This proposed architecture permits different OPC-based process control architectures from a wide range of fields to communicate with each other. Thus, OPC-based local control systems located in different places can communicate with each other on the Internet without using bus architecture. The basic functions of the proposed system were implemented using the Delphi software package. Local control architectures developed at N points can communicate with each other and a remote control point on a dynamic web page constructed using Active Server Pages (ASP). Consequently, the proposed DOPC architecture allows the user to control and monitor local systems from any location with internet access, and to implement data exchange between N OPC points.

Designing a reliable leak detection system for West Products Pipeline

The system using “OPC” (OLE for process control) technology to obtain signals with high frequency, and the signals contain pressure, flow rate, temperature and the operation parameters of pumps and valves. Process information fusion method is applied to enhance leak sensitivity, reduce false alarm rate and improve location accuracy. A leak detection system is established based on SCADA system on the 1858-km long West Products Pipeline, experience which demonstrates that the leak detection system is sensitive and reliable.

VPS-versatile power supply control system

Versatile Power Supply (VPS) Control is a component of a network-based control system and SCADA software with a client/server architecture developed using the Datalogging and Supervisory Control (DSC) by National Instruments. Installing OLE for Process Control (OPC) in the data server of VPS allows access to every kind of CAEN power supply (SY1527, SY527, etc.) that supports OPC server functionality and achieves integration of data and operation. Using VPS Graphic Panels, graphical menus with various data presentations have been created, so a new CAEN modules can be added without writing new code but only extending the Citadel Data Base. The data acquired to the Data Base server are accessible from the network.

A middleware for web service-enabled integration and interoperation of intelligent building systems

This paper describes a middleware framework for integrating heterogeneous building automation systems (BAS) on the Internet. The proposed framework combines OPC (OLE for Process Control) and Web Services to integrate data and services on the Internet. It utilizes the OPC technologies in LAN and the powerful communication capability of Web Services to accommodate different communication interfaces/protocols and provide public Web Services methods. These public Web Services methods can be invoked by heterogeneous BAS or other enterprise applications to realize BAS integration and interoperation with enterprise applications on the Internet, thus filling the gap between BAS control network and data communication network. The design and implementation of the middleware technology are presented in this paper. Experiments and evaluation on performance of the middleware are also conducted and presented.

AN EDUCATIONAL PLANT BASED ON THE QUADRUPLE-TANK PROCESS

This paper presents an experimental tank system developed at the University of Seville for process control education. This plant is based on the well known quadruple-tank process and some modifications have been done in order to obtain a wide range of applications. The quadruple tank process is a multivariable laboratory plant of interconnected tanks that can be easily configured to exhibit the effect of multivariable zero (minimum and non-minimum phase) on the system behavior, as well as the effect of non linear dynamics, saturation, constraints, etc.In the real plant implementation, the original structure of the process has been modified to offer a wide variety of uses for both educational and research purposes. Thus, different plants can be configured such as one single tank, two or three cascaded tanks, a mixture process and hybrid dynamics. Moreover the dynamics parameters of each tank can be set up by tuning the cross-section of the outlet hole of the tank. Furthermore, the real plant has been implemented using industrial instrumentation and a PLC for the low level control. Supervision and control of the plant is carried out in a computer by means of OPC (Ole for Process Control) which allows one to connect the plant with a wide range of control programs such as LabView, Matlab or industrial SCADA.

THE OPC IN WAREHOUSE MANGEMENT SYSTEM

This paper presents the development of one warehouse traceability application which intends to create a log of all components that are introduced into one warehouse. Several communication protocols, wireless code bar systems, programmable logic controllers (PLC), human machine interfaces (HMI) and OLE for process control (OPC) servers were used. This application is responsible to get and save into a database all the necessary information's to clarify and get answers that explain and avoid the sporadically appearance of components in wrong warehouse shelves. The traceability application uses one OPC server to access and control the PLC and it will be presented a practical assessment of it performance and reliability.

Development of an artificial neural network-based software for prediction of power plant canal water discharge temperature

Power plant cooling water systems that interact with nearby effluents are complex non-linear, large-time-delay systems. A neural network-based software tool was developed for prediction of the canal water discharge temperature at a coal-fired power plant as a function of plant operating parameters and local weather conditions, including tide information. The plant has four units totaling an installed capacity of 1550MW and its water thermal discharge is environmentally regulated. In the summer months, when the price of electricity is very profitable and the risk of exceeding the canal temperature limit is greater, the tradeoff between maximum generation and environmental compliance violations is financially significant. The software is a predictive tool to assist in scheduling load generation among the plant's four units without exceeding a thermal discharge limit of 95^oF. Back propagation neural network architectures were trained using plant operating data with an 'off-set' component. The artificial intelligence models produced reasonable trends for year-round prediction and different operational scenarios. Comparison of measured and predicted canal temperatures indicated an accuracy of less than 0.3^oF over the range between 90 and 95^oF. The software tool was developed as an Object Linking and Embedding (OLE) for Process Control (OPC) client, with real-time communication and interface with the plant Distributed Control System (DCS).

OPC based distributed real time simulation of complex continuous processes

This paper presents a methodology for the development of distributed process simulation using OPC (OLE for Process Control). The distributed components operate as OPC servers enclosing continuous simulations developed with the simulation language EcosimPro. The paper presents the problems related to data interchange and synchronisation in real time and the solutions adopted and gives results about the performance of OPC in this kind of applications. The methodology has been applied to a large process simulator of a beet sugar factory used for control room operator training. This includes a process simulation operating in a network of six computers, a SCADA system for operation on the process, an instructor console and the corresponding software for real time communication and synchronisation. The main advantages of this approach are: (i) independence of the development of the simulation from the communication mechanisms, (ii) access to the simulations by a wide range of applications, due to the standard provided by OPC, (iii) use of low cost conventional equipment and (iv) support for large scale simulations.

Access to industrial process periphery via Java for process control (JFPC)

Using Java for real world I/O requires its availability in real-time (RT) systems. It is widely accepted that in a plain Java environment, RT characteristics get lost and the required programming interfaces are missing. So there are several ongoing standardization efforts for RT Java. An essential aspect (also important for non-RT systems) is the access to external I/Os. The Siemens product Java for process control (JFPC), which is based on the ideas of OLE for process control (OPC) addresses this aspect. It is available under the proprietary RT kernel RMOS and under Windows NT. Forschungszentrum Julich developed different JFPC providers in order to access industrial components via PROFIBUS DP using an experimental version of JFPC under Linux. The paper presents the status of the different standardization efforts for RT Java and the key features of JFPC. It describes the implementation of a JFPC provider for PROFIBUS DP and shows how it can be used to access industrial sensors and actuators. Experiences and performance results are discussed.

Conception and Implementation of an Object Request Broker for the Integration of the Process Level in Manufacturing Systems

In order to be able to react quickly to altering production states, planning tools such as Manufacturing Resource Planning and Enterprise Resource Planning heavily rely on up to date information about the process itself. Thus, access to process level data is one of the most important issues within the production industry. However, the process level lacks support for open, connective communication systems as the number of incompatible fieldbus systems shows. Current solutions, e.g., OLE for Process Control, only focus on a unified interface to the process level, but do not allow to access the functionality of a field device directly. The approach presented in this paper introduces FIMO, the Fieldbus Messaging Object Request Broker, to be deployed in field devices and utilizing the existing fieldbus protocols. With the use of FIMO, devices connected to a fieldbus can be seamlessly integrated in the whole manufacturing hierarchy. The paper gives a brief overview of thestate of the art for accessing process level data. Then, the FIMO architecture is presented in detail including its core services and the mapping of the communication services to the underlying fieldbus system.