| 摘要 |
PURPOSE:To attain the multiple address communication even with a protocol of data flow control in the CSMA/CD system by providing a reply supervisory timer to each terminal equipment so as to check a reply signal returned within a prescribed time thereby allowing the sending side to discriminate accurately whether or not the multiple address communication is successful. CONSTITUTION:In applying multiple address communication from a terminal equipment A to terminal equipments B-D, a connect command CNC is sent from the terminal equipment A while using a group number to the terminal equipments B-D as an address. A timer 11 for reply wait supervision is started at the same time. In this case, a control section 16 describes the number of terminals being multiple address destination to a multiple address number holding section 13. If a reply signal is received, a reply supervisory section 12 confirms a reply signal CACK, the signal is informed by a control section 16, which counts up a reception counter 15. Every time an affirmative CACK is replied from the terminal equipments B D, the reception counter 15 is counted up. At the time of the timer 11 is over, the control section 16 checks the count of the counter 15 and compares it with the multiple communication number described tentatively in the multiple address number storage section 13.
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