Reliability and self-diagnosis aspects of micro processor controlled instrumentation systems

Abstract

The introduction of programmable LSI components in instrumentation devices and systems creates both new problems and new performances concerning reliability and behaviour in presence of faults. Problems derive basically from the difficulty of evaluating reliability characteristics, both at component and at system level; conventional methods for testing and for reliability assessment do not appear adequate any more. On the other hand, the presence of a component with data processing capabilities and the consequent availability of distributed intelligence at acceptably low cost allow to introduce diagnosis and error confinement performances, even when no higher fault-tolerance capacities are considered. While proper “reconfiguration” techniques cannot, in general, be considered in a realistic way for the systems being examined, state identification is important both for subsequent maintenance and for fail-safe behaviour.