| 摘要 |
PROBLEM TO BE SOLVED: To provide a data communication system and a data communication method capable of avoiding collision caused on the occurrence of data transmission requests from a plurality of sub apparatuses at the same time so as to enhance a data transfer rate. SOLUTION: A hot line HL for data transfer and first and second control lines C1, C2 for controlling the transmission sequence of the data transfer on the hot line HL are provided between a master apparatus 1 and the sub apparatuses 21, 22,.... When the sub apparatus makes data transfer, first the sub apparatus transmits the transmission request to the master apparatus 1 via the first control line C1. When the master apparatus 1 detects transmission requests from a plurality of the sub apparatuses, the master apparatus 1 selects and decides the sub apparatus whose priority is highest on the basis of a history of the transmission requests stored in a communication request history / priority control section 7 and exclusively transmits a permission output of one system. COPYRIGHT: (C)2004,JPO
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