Process control instrumentation namely operator interface units and digital controllers, configuration and tuning modules, operator consoles; process control units namely controller modules, logic master modules, digital slave modules, analog slave modules, analog master modules, analog output modules, controller interface modules; termination units for computer interface and process input and output wiring; and power modules for both modulating and sequential output wiring; and power modules for both modulating and sequential control, data acquisition, operator interface and computer interface for industrial and utility applications; stand-alone controllers, communications interfaces, smart transmitters or monitors and configuration engineering modules