Optimizing fault tolerance in embedded distributed systems

This article considers a gas-insulated switchgear (GIS) station. Here, all switches are located in SF/sub 6/ gas volumes, offering a much better isolation and spark-extinguishing property than air, and thus leading to a far more compact size. All volumes have one or two sensors for monitoring gas density. The station's distributed computing system is arranged in several levels. PISAs-embedded computing systems for preprocessing the data from digital/analog converters and for writing them on the process bus (PB)-link to the sensor and actuator hardware. PISAs in the switches also take the actuator commands from the process bus and carry out the switching actions.