| 摘要 |
PURPOSE:To prevent a system from breaking down due to a break in electric power feed by providing an electric power change-over circuit which connects any of electric power source systems to common peripheral equipments by switching. CONSTITUTION:Through input-output bus 13, CPU11 interchanges information with peripheral equipment IOs141-14k dedicated to the A-system. On the other hand, CPU12 interchanges information with peripheral equipment IOs171-17 dedicated to the B-system through input-output bus 16. Then, input-output buses 13 and 16, connected to bus change-over circuits BSU21 and BSU22 via bus extending circuits BEA15 and BEA18, enable information interchange between common peripheral equipment IOs231-23m, and 241-24n, and corresponding CPUs 11 and 12. Through electric power change-over circuit 27, the electric power sources of the common peripheral equipments and bus change-over circuits supply-electric power to either of the A- and B-systems and in case that one electric power source is disabled, the other electric power source substitutes to prevent the common system from being disabled. |
