| 摘要 |
PURPOSE:To continue the data communication processing without intermission even if the system is switched to a standby system due to a fault by commanding pseudo connection of line to the standby system and allowing the standby system to apply pseudo connection accordingly after the end of line connection in the active system. CONSTITUTION:When the connection to a line is finished in the active system, a line pseudo connection command is sent from the active system CPU 11 to the standby CPU 21 system. The CPU 21 issues a line pseudo connection command to a communication controller 22 of its own system and the controller 22 applies line connection in a pseudo way accordingly. That is, the controller 22 applies initial setting for line open in a pseudo way regardless that no line is connected actually and no reply comes from a line terminator such as a MODEM. The CPU 11 transfers the processing state to the CPU 21 at each section of the processing step. If a fault takes place in the active system and the changeover to the standby system is executed, the initial setting of the line connection is finished in the controller 22, the CPU 21 references the processing state of the active system stored to continue the communication.
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