Patent ID: 7292897

Claim:
A multiplexing control system comprising a sensor which detects a state variable in a process; plural microcomputers which are inputted of a process signal detected by the sensor and output a control signal for the process and one of which operates as a master; a process input/output unit which is provided in common for the plural microcomputers and distributes a process signal detected by the sensor respectively to the plural microcomputers, wherein the process input/output unit includes interface boards corresponding respectively to the plural microcomputers and the process signal inputted to the microcomputer operating as the master is written in a memory corresponding to the other microcomputer; in which process input/output units which input/output process signals are provided for every process signal, wherein a redundancy structure of each of the process input/output units which inputs/outputs a concerned process signal is varied depending on the type of the process signals and further a signal of a process input/output unit having small redundancy is designed to be inputted/outputted via a process input/output unit having large redundancy.