| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for communication between control devices capable of transmitting/receiving a large quantity of signal data at short control frequencies in control systems connected to each other through a network. SOLUTION: A signal data between the control devices comprises a pair of attribute signal data 10A and a value signal data 10B. The attribute signal data 10A comprises an attribute ID and attribute data, and the value signal data 10B comprises an attribute ID and a plurality of signal value data. On the transmission side, first the attribute signal data 10B and the value signal data 10B are transmitted (S1, S2), and then only the value signal data 10B is transmitted (S3). On the receiving side, when the received attribute ID is compared with the previous attribute ID (S4) and they are the same, the signal value data 10B is so used as to correspond to the order of the stored attribute signal data 10A (S15). If they are different from each other, the receiving side requests the attribute signal data of the transmission side (S16), and the transmission side transmits only the attribute signal data according to the request (S4) (S5). COPYRIGHT: (C)2009,JPO&INPIT
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