Abstract: A protection system for a complex process has four redundant protection sets, each of which produces partial reactor trip and partial safeguard actuation signals in pairs of microprocessor-based controllers. Two independent and redundant voting logic trains are provided for the partial reactor trip signals, and two identical, independent and redundant voting logic trains are provided for the partial safeguard actuation signals. Each of the trains includes a pair of redundant microprocessor-based voting logic controllers, each of which receives the partial reactor trip or partial safeguard actuation signals from each of the process protection sets and has a voting processor which generates an intermediate reactor trip or intermediate safeguard actuation signal in response to partial signals from a predetermined number of protection sets. The intermediate signals from the two voting logic controllers in each train are ANDed to generate train signals.

Abstract: An electrical circuit backfits into different instrumentation and control (I&C) system hardware configurations as a replacement or upgrade. The circuit has a multiple signal path processing circuit including a multi-functional ASIC. A fixedly configured, multiple signal path connector such as a hardwired multi-pin package removably connected with a pin socket in the processing circuit connects the ASIC with the I&C system for coupling inputs to and outputs from the ASIC and for selecting operative signal paths of the ASIC.

Abstract: An electrical circuit backfits into different instrumentation and control (I&C) system hardware configurations as a replacement or upgrade. The circuit has a multiple signal path processing circuit including a multi-functional ASIC. A fixedly configured, multiple signal path connector such as a hardwired multi-pin package removably connected with a pin socket in the processing circuit connects the ASIC with the I&C system for coupling inputs to and outputs from the ASIC and for connecting operative signal paths of the ASIC.

Abstract: The present invention relates to a method and apparatus for testing analog process protection and control systems which are composed of a plurality of channels each serving to monitor a selected process parameter.

Abstract: A redundant power supply for digital control systems, such as one using a MULTI-BUS backplane which utilizes remote sensing power supplies and level holding capacitors to provide continuous operation when one of the power supplies fails. Embodiments of the invention include a dual redundant power supply system for a backplane having a pair of power buses which provide positive five volts, positive twelve volts and negative twelve volts with reference to ground. Equipment drawing relatively high currents, e.g., 40 amperes, can be continuously supplied with power at a voltage regulated to within .+-.0.1% of nominal values for each 10% change in current.