Implementing fault-tolerance via modular redundancy with comparison

An NMRC (N-modular redundancy with comparison) system is presented. It surpasses all existing NMR systems in fault tolerance capability. The extra logic needed by NMRC is simpler than that of the other NMR systems. The relation between the interconnection topology and the fault tolerance capability of the NMRC system investigated. Three types of optimal NMRC systems and their characterization and structure are studied. NMRC can be viewed as a diagnosable system. The comparison approach is applied to t/sub 1//s-diagnosable systems, whereas previously it had been applied only to t/sub 0/- and t/sub 1/-diagnosable systems. A laboratory 3-MRC system has been built as a node computer for a fault-tolerant multicomputer system for industrial process control. The test results confirm the high reliability and effectiveness of NMRC.<
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