A distributed fault tolerant architecture for nuclear reactor and other critical process control applications

Abstract

A distributed fault tolerant system for process control that is based on an enhancement of the distributed recovery block (DRB) is described. Fault tolerance provisions in the system cover software faults by use of the DRB; hardware faults by means of replication and the DRB; system software faults by means of replication, loose coupling, periodic status messages, and a restart capability; and network faults by means of replication and diverse interconnection paths. Maintainability is enhanced through an automated restart capability and logging function resident on a system supervisor node. The system, called the extended distributed recovery block, or EDRB, has been implemented and integrated into a chemical processing system.<>