| 摘要 |
PURPOSE:To furnish an inexpensive, highly reliable transmitting system by providing a clock generating device and a transmitting right generating device in each station and giving a transmitting right resending mechanism and a clock right on the occasion of loss of transmitting right to a station having obtained transmitting right. CONSTITUTION:On receiving a transmission start command C3, a parallel-series convertor 9 outputs a transmitting frame FR as a series signal. After completion of sending the frame FR, the convertor supplies a transmission completion command C4 to a transmitting right generating device 13. The device 13 is provided with a shift register of 16 bits and a device that sets a zero signal Z and a go-ahead-signal GA thereto, and when there is a request for sending the transmitting right TN, sets the transmitting right TN to the shift register and sends out. In the case where the transmitting right is lost or the frame FR does not arrive at own station, a count value NL of a timer 25 goes up, and when it conforms with a set value ML of a lost time setting device 11, an coincidence signal EL makes a bit delay circuit prohibited state and stops the relaying action. At the same time, the transmitting right TN is sent again from the device 13. |
