JPS6141402B

Novel method and system for controlling input/output in a process control wherein state signals of object processes to be controlled are applied to a CPU via a process input/output unit and operated in the CPU in accordance with a logic programmed and stored in advance, and results of the operation are delivered out to the object processes to control the same. A buffer memory is interposed between the CPU and the process input/output unit. While reception and delivery of data are performed between the CPU or processor unit and the buffer memory, fetching of the state signals of the object processes or delivery of the process controlling signals is performed between the buffer memory and the object processes, thereby attaining a high rate processing as viewed from the overall processing of the system.