| 摘要 |
PURPOSE:To continue switching service without any urgent control operation even if a fault is generated in one main storage device by forming a circuit for always displaying fault signals of respective main storage devices. CONSTITUTION:The titled main storage device is constituted of a single central controller 1 and doubled main storage devices 2 and an input signal 3 is simultaneously written in both the main storage devices 2 as information writing. An output signal from a failed main storage device 2 is invalidated by a fault signal 5 from the failed main storage device 2. Since the fault signals 5 of respective main storage devices 2 are always monitored by a fault signal display circuit 7, the failed main storage device is replaced by a spare main storage device, so that the double operation of the main storage devices can be always attained. Thus, the switching service can be attained without any urgent control operation even if a fault is generated. |
