Title: Interprocess Communication Primitives for Distributed Process Control
Abstract: In order to realize the potential for reliability and maintainability offered by distributed computer control systems in real-time process control applications, it is essential to have flexible methods for incorporating redundancy. A practical architecture based on local-area network technology which supports this incorporation of redundancy is proposed. A set of classification criteria for interprocess communication primitives is given and the applicability of the various proposals which have appeared in the literature is analysed. An approach based on the validity time of messages is outlined. This concept permits a unified treatment of message transfer protocols and transparent redundancy in the application software.