Web Services-based Process Control System Integration

Process Control Systems (PCS) broadly exist in the manufacturing enterprises. PCSs are the control center of the manufacturing process and they are the manufacturing process data source for other enterprise information systems. Different PCS utilized different deployment technologies and communication networks, deployed and maintained by different vendors and operated on heterogeneous platforms. This results in the shortage of interoperation among PCSs and information sharing between PCSs and other enterprise information systems. So, the notorious "Information Island" is formed. In order to eliminate the "Information Island" and improve the produce efficiency, PCSs need to be integrated.Object-oriented Middleware based solutions are the main traditional PCSs integration method. But these solutions have their limitations because of object-oriented middleware's own character. The limitations include: requiring same system architecture, restricted by firewall and shortage of interoperation between different component models. This thesis studies the PCSs integration using the Web services technologies.Web service has the characteristics of encapsulation ability, loosely coupled architecture, standardized protocol, high interoperability and integration ability, etc. It is the ideal technology for PCSs integration. Web service helps to solve the traditional problems in integration.Enterprise information systems are abstracted into a three-layer structure. Then, based on the structure and using Web services as the key technology, we propose a Process Control Systems' Integration Framework (PCS-IF). It is a generic framework and can be used as a guide. Process Control Systems' Integration Platform (PCS-IP) is the main part of PCS-IF. This thesis introduces Function Block (FB) concept in PCSs integration at the first time. The functionality of the PCS-IP is mapped into ten FBs. A FB is a software entity, which can complete some specific tasks. FBs can interoperate with each other. The interfaces of function blocks are encapsulated as Web services. We also provide a design and implementation flow for PCSs integration. The experiment of two process control systems is carried out. Through the successful experimental integration of two process control systems, the feasibility of Web services based integration is verified, and the advantages are showed.