| 摘要 |
<p>PURPOSE: To improve transmission efficiency and to correct the unbalance of the transmission frequency between nodes by retransmitting transmission data after prescribed time after the unmatching between transmission and reception data is detected and abolishing reception data which is less than the length shown by a reception message. CONSTITUTION: The messages (Me) to/from up and down transmission lines 31 and 32 are transmitted and received by a terminal 11 via the transmission circuit 53, the reception circuit 58, the control circuits 52 and 63, and buffers 51 and 64 of a modem 21. As for the modem 21, when a transmission and reception data comparsion circuit 60 compares transmission and reception data and detects the unmatching at the time of a Me transmission, a retransmission control circuit 61 retransmits the Me after prescribed time. When the length of reception data is less than the Me length shown by the reception Me when the modem 21 does not transmit Me, the reception control circuit 63 destroys reception data. Thus, the generation of a collision is decided by the unmatching between data, transmission efficiency can be improved and the unbalance of transmission frequency between nodes can be corrected.</p> |
