Evaluation of fault-tolerant microcomputer system by fault injection method

A method for evaluation of fault-tolerant microcomputer system based on fault injection is described in this paper. Fault injection equipment is based on personal computer with additional specialised I/O card. The tested fault-tolerant microcomputer system is based on cold-spare standby. This system consists of standard nonredundant modules and specific additional modules. The validation of active unit in standby configuration is performed by the watch-dog timer and redundant software with comparison. The results of testing are given as a number of detected faults and the number of failures of the whole system as a function of the fault duration for two fault logoc levels. The fault detection coverage and fault recovery coverage are evaluated by using the results of fault injection. The tested system is evaluated for nonredundant and redundant software.