Abstract: The present control apparatus and method for controlling a plurality of intercoupled industrial process operations each having an operation control member. The control member position correction is implemented in accordance with a predetermined characteristic so as to minimize undesired interference with the other industrial process operations.

Abstract: The present control system and method for controlling the combustion chamber pressure in a non-linear combustion process is operative in relation to one or more combustion chambers each having a flue gas damper. In the case of a plurality of such chambers, the outlet duct associated with each chamber is connected to a common exhaust stack. This operation is in relation to a desired damper position control characteristic provided by a combination of process signals in a microprocessor computer apparatus. Information in the form of the combustion and pressure levels as supplied in an anticipative feed-forward control manner by a particular combustion chamber is utilized in conjunction with a variable gain characteristic determined by the actual position of the damper operative with that combustion chamber to determine the correct damper position for that chamber.

Abstract: A control system and method are provided for an industrial process operation, wherein a controller is coupled with a process control member and has a gain that is adjustable in accordance with a predetermined relationship of the controller reference iteration interval and the controller actual execution interval.

Abstract: An apparatus is provided for sensing the state of high voltage contact inputs in a process control system. Lower voltage contact closure input modules cooperate with a reference bus and reference bus regulator to reduce the voltage drop across an input module when a pair of contacts is closed, thereby reducing the energy dissipated and heat created by the input module.