Methods and apparatus to upgrade and provide control redundancy in process plants

摘要

A method to provide control redundancy for a process plant control system, the method comprising and providing a control input to a first instance of control software sub-system and to a second instance of the control software sub-system and to at least a third instance of the control software sub-system, wherein the instances process the control input in parallel, and wherein the number of instances is dynamic, depending on the current processing loads of available controllers; and providing the output of one of the instances to a process plant field device, wherein said first instance of control software sub-system is a master that collects the outputs of the instances; and performs voting among the instances to select the output to be communicated to the process plant field device.