| 摘要 |
PROBLEM TO BE SOLVED: To provide a programmable controller for actualizing a duplication of a network system that does not depend upon a type of a network system. SOLUTION: The programmable controller is provided with a CPU unit 12, and a first communication unit 13 and a second communication unit 14 connected to transmission paths 30 and 31 that are different systems from each other, and the first and second communication units collect subscription states of nodes connected to the first and second transmission paths 30 and 31, respectively. The CPU unit first makes a request to the first communication unit when transmitting a message. When the first communication unit receives a transmission request of a message, the first communication unit determines whether to be transmittable to a node of a transmission destination on the basis of the subscription state of a network connected to the first transmission path, transmits the message as it is if transmittable, and makes a request to the CPU unit to transmit the message by the second communication unit if not transmittable. The CPU unit makes a transmission request to the second communication unit on the basis of the request, and the second communication unit transmits the message if transmittable on the basis of the node subscription state of the second transmission path. COPYRIGHT: (C)2008,JPO&INPIT
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