| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide means capable of transmitting history data with a reduced network load.SOLUTION: In a communication system including a plurality of node devices disposed on a ring network and a control device, connected to one of the node devices, for monitoring the ring network, each of the plurality of node devices includes a control unit, a generator unit and a transfer unit. The control unit receives and downloads download data. The generator unit adds history data, indicative of the completion of the download, to a shared file that is shared with other node devices. The transfer unit transfers the shared file having the added history data and the download data to an adjacent node device in the transmission direction. The control unit of the node device connected to the control device downloads the download data received from the control device, and transmits the shared file to the control device on receiving from the adjacent node device the shared file including the history data of each node device on the ring network.</p> |
