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Title:
COMMON INPUT/OUTPUT APPARATUS CONTROL SYSTEM
Document Type and Number:
Japanese Patent JPH02199567
Kind Code:
A
Abstract:

PURPOSE: To replace a fault input/output (I/O) control device by a normal one without stopping system operation by outputting a signal from a CPU to a common I/O apparatus mutually and directly connected to each of I/O control duplexed devices at a low impedance state only when their own device sets up as an in-use system.

CONSTITUTION: Central control devices 9, 10 are duplexed to control the common I/O apparatus 3 through either one of the I/O control devices 1, 2. System switching control circuits 1c, 2c provided in the devices 1, 2 in the system monitor various fault in their own device during the period that their own device functions as in-use system, and at the time of detecting a fault, release the excitation of a relay and inform the fault information to a control circuit 1c or 2c on the spare side through an external cable 8. Based upon the information, a signal outputted relay contact 1e is released by the I/O control circuit 1a or 2a and a level conversion circuit 1d or 2d in each device 1 or 2.


Inventors:
AOKI TOSHIKAZU
Application Number:
JP1989000017799
Publication Date:
August 07, 1990
Filing Date:
January 30, 1989
Export Citation:
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Assignee:
HITACHI COMMUNICATION SYSTEM
International Classes:
G06F13/14; G06F11/20; G06F13/00; (IPC1-7): G06F11/20; G06F13/00; G06F13/14