Design and implementation of a Web-based distributed control system

This paper describes a framework of Internet-based distributed control system and the design and implementation of its software in a multiple server/client environment. Main issues addressed in this paper are the infrastructure of the system, the functionalities of components, and real-time scheduling behaviors of the software. Both event and time triggered real-time scheduling has been adopted. Built-in dependability technologies are adopted to ensure customized applications can be integrated into the distributed system easily. The programmable and re-configurable framework of the system provides a flexible mechanism for constructing distributed real-time applications. A language neutral interface is used for communication and data access between distributed nodes. Connectivity and controllability of virtual Web devices and their interoperability are described. Because of the importance of timeliness and dynamics in real-time systems, emphases have been put on time and event scheduling for Web-based distributed systems.