| 摘要 |
PURPOSE:To prevent a reduction of the effective transfer speed of a transmission line and to prevent giving permission to a transmission request of the same sequence that is generated later, by performing comparison of priorities of one messages having transmission requests at the same time as the transmission of information. CONSTITUTION:An information frame is supplied to a shift register 11 from a transmission line 1a via a demodulator 18. The output of the demodulator 18 is supplied also to a frame detecting circuit 10. Thus both the initiation and the termination of a frame are known and transmitted to a control part 22. When the frame is detected, a bit pattern is decoded by a decoder 12 to decide an advanced frame GA, an information frame MES or a search frame SH. When the frame SH arrives, a priority region is fed to a comparator 14 and compared with the contents of a priority register within the part 22. The result of comparison is transmitted to the part 22 via a signal line 106. If the priority of the own station is low, the frame SH is transmitted as it is from the register 11. |
