| 摘要 |
PURPOSE:To attain priority communication having strong decentralization of control by allowing a clock station to transmit a signal fitted with priority information, allowing a node station to compare the priority of a signal desired to be transmitted with the said information, and to transmit the priority information in addition to the own signal when the right of transmission is acquired. CONSTITUTION:Fig (a) shows a synchronizing signal and a trigger signal transmitted by the clock station CS, Fig. (b) indicates a signal block between the node stations NS and Fig. C depicts a signal on a loop. A control circuit 13 of the NS stores the signal block into a buffer 18, a priority comparator circuit 16 compares the priority level with a level PRI from the control circuit 13, and when the former is higher or the same, the control circuit 13 selects a switch 30 to the position of the buffer 18 so as to start transmitting a preamble PR. When the signal detecting circuit 14 detects the PR during transmission, the circuit 13 stops the transmission. When no PR is detected, the right of transmission is acquired, and the circuit 13 gets the comparator 16 to write the priority level PRI in the signal block for output. The control circuit 24 of the CS gets the priority setting circuit 26 to write a level 0 to the signal block for transmission. |
