| 摘要 |
PURPOSE:To prevent data collision while actual data is transmitted by completing the detection of data collision during the transmission of a transmission destination address and an origin address. CONSTITUTION:When transmitting terminals 302 and 304 start transmission to different destinations at the same time, they output the 1st bit of starting data. The terminals 302 and 304 both outputs ''1'', but data collision is not detected by a data comparing circuit 33 in this state. When the terminal 302 outputs the 2nd bit ''0'' and the terminal 304 oututs the 2nd bit ''1'', a serial data line is held in a ''0''-level state; and the data comparing circuit detects data collision owing to the difference between output data and input data and the terminal 304 enters into reception mode. When they start transmission to the same destination at the same time, the transmission sides output transmission destination addresses as starting data. The address coincide with each other, so a data collision state is not detected while the data are transmitted. Once their origin addresses are transmitted as next data, data collision is detected in said state and evaded. |
