Built in test and health monitoring for fault tolerant systems

Deployed test and health monitoring systems must actually manage two tasks: (1) the testing and monitoring the device under test, and (2) the testing and monitoring the test system itself. The ability to isolate and identify faults is crucial to deployed test and health monitoring systems. Understanding failure mechanisms provides invaluable insight regarding whether the device under test is, in fact, the failure, or if something in the test and monitoring system is faulty: the sensor, the hardware, or the interconnect/cabling system. Efficiently and effectively isolating marginal components or interconnects can save hours of costly product analysis, system downtime, and test efforts, and in extreme cases, it can also save lives. This white paper reviews technology used on two separate projects: 1) remote health and safety monitoring of hybrid bus fleets, and 2) remote fault monitoring of DAQ/Control units.