SYSTEM CHANGE CONTROL SYSTEM

PURPOSE:To prevent the erroneous access from a stand-by system upon a current system by inhibiting the access from a stand-by circuit to a single system control circuit when a route change inhibiting FF of a current circuit of dual circuits is set. CONSTITUTION:Circuits 10, 21, and 30 are used as th...

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Bibliographic Details
Main Author TANABE YOSHIICHI
Format Patent
LanguageEnglish
Published 06.03.1986
Subjects
CALCULATING
COMPUTING
COUNTING
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRIC DIGITAL DATA PROCESSING
ELECTRICITY
PHYSICS
SELECTING
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Summary:PURPOSE:To prevent the erroneous access from a stand-by system upon a current system by inhibiting the access from a stand-by circuit to a single system control circuit when a route change inhibiting FF of a current circuit of dual circuits is set. CONSTITUTION:Circuits 10, 21, and 30 are used as the current system, and circuits 11, 20, and 31 are used as the stand-by system. This condition is prescribed by setting FFs 410 and 420 of a system control circuit 4 to ''1'' and resetting FFs 411 and 421 to ''0''. At this time, an FF 110 in the circuit 10 used as the current system in a circuit 1 having the interface to another device is set to ''1''. Since the FF110 corresponds to a gate 1000 and an FF111 corresponds to a gate 1001, the gate 1001 is closed to disconnect the circuit 11 from the circuit 4. Consequently, the access from the stand-by circuit 11 to the circuit 4 is inhibited, and system change is impossible. Since the access from the current circuit 10 to the circuit 4 is not inhibited, system change is always possible in the current side.
Bibliography:Application Number: JP19840168639