| 摘要 |
<p>A transmission-side device broadcasts a download start telegram containing object device designating information and a broadcast identifier to all the reception-side devices and then a data telegram containing the same broadcast identifier contained in the start telegram and data to all the reception-side devices. Each reception-side device stores the broadcast identifier in the download start telegram when the attribute information of itself satisfies the object device designating information contained in the download start telegram, and then fetches the data in the data telegram when the broadcast identifier in the data telegram coincides with the broadcast identifier stored in itself. Therefore, no troublesome operation is required in advance for designating which reception-side device receives which data. Since the telegram containing information for designating an object device and the telegram for data transmission are separately used, it is unnecessary to set update information in the data transmission telegram, thereby improving the data transmission efficiency. Further since the telegram containing the information for designating an object device and the data transmission telegram are broadcast, the data can be downloaded in a short time.</p> |
