| 摘要 |
PURPOSE:To secure data transmission by reducing the volume of information to be sent, by sending a backup request to a data transmitter at a transmission side when a data transmitter at a reception side run into trouble. CONSTITUTION:In a normal period, data transmitters 1 and 3 perform data transmission in the transmission format consisting of a [synchronous] word and [information 1]-[information (n)] words as shwon by (a). When a fault happens to data transmitter 3, the [information B] word making a backup request according to the transmission format shown by (b) is repetitively sent to data transmitter 1 several times. Data transmitter 1 transmits the [information B] word to computer 2. Then, computer 2 is placed in backup mode and information to be sent to data transmitter 3 is selected, proceeding to operation with the volume of information reduced. |
