The main type controller which keeps the double conversion process control equipment

摘要

PROBLEM TO BE SOLVED: To make control data coincident without stopping control over a process 3 to be controlled even when a standby system updates a control program.SOLUTION: An A-system controller 1a of a main system selects control data to be made coincident out of control data obtained by a control program 11a based upon coincidence instruction data stored in a coincidence instruction data storage part 16a, and transfers control data for coincidence constructed having the selected control data and the ID of the control data associated with each other to a B-system controller 1b. The B-system controller 1b of a standby system selects control data for coincidence having the same ID as an ID included in coincidence instruction data stored in a coincidence instruction data storage part 16b of its device from the transferred control data for coincidence, and rewrites control data stored in an address in a control data memory 12b specified with the coincidence instruction data of its device using control data included in the coincidence control data.