PURPOSE: To take out only the necessary data for the designated CPU without interrupting other CPUs by connecting a memory to a bus line which secures the connection among plural CPUs and storing the common data required by 2 CPUs into the memory.

CONSTITUTION: A CPU 1c writes the present action mode and the parameter of a system into the prescribed addresses of a RAM 9 and then updates the data every time these mode and parameter are changed. If the tacts neessary for the CPU 1a and 1b occur, the CPU 1c has an access of the corresponding data to the RAM 9 to take out these data. Then both CPU 1a and 1b preform each control. If the CPU 1a and 1b change the action mode and the parameter of each depart ment in charge, the data are once written in the RAM 9 and then read out by the CPU 1c. Based on these data, the entire control state is set in an optinum state.