I/O server services configured to facilitate control in a process control environment by containerized controller services

Bidirectional communication between field devices and active containerized controller services in a process control environment. An I/O server service within a container 511A receives 540, 542A-B a set of process outputs obtained by field devices 531-533 e.g. measurements from a particular portion of an industrial process at a process plant. The I/O server service generates from the process outputs a plurality of sets of controller inputs 543A-C, each with the same values, and sends each set to a different one of containerised controller services 521A-C. Each controller service executes the same control routine 525A-C to control the same portion of the same industrial plant by generating a set of controller outputs on a plurality of I/O channels 544A-C. The plurality of sets of controller outputs are received by the I/O server service and include an active set of controller outputs. The active set of controller outputs are then transmitted to the field devices to drive a process output and control a particular portion of the industrial process. Prior to transmission it may be verified that the active set of controller outputs have been refreshed within a given time period to confirm that they are not stale.