| 摘要 |
PURPOSE:To prevent a closing loop to be constituted by providing a means to prohibit the loop back of a self-reproducing repeator from a point of time the loop back command ot another reproducing repeator is received to a point of time the loop back canceling command of any reproducing repeator is received. CONSTITUTION:When the loop back command of the other reproducing repeator is received, a loop back command output 20 of a command identifying circuit 8 goes to be an H level and an output 21 of a repeator number identifying circuit 9 goes to be an L level. However, by an inverter circuit 14, the output of an AND gate circuit 12 goes to be the H level and an output Q of an SRF/F circuit 15 goes to be the L level. Accordingly, even when the loop back command of a self-reproducing repeator 1-U is next received and the output of an AND gate circuit 10 goes to be the H level, the output of an AND gate circuit 13 goes to be the L level. Thus, the loop back is not formed. When the loop back canceling command of any reproducing repeator is received, the output Q of the SRF/F circuit 15 goes to be the H level and normal loop back operation can be executed. |
