| 摘要 |
PURPOSE:To attain the synchronous switching over wide range of phase differences with no hit nor code error by securing a parallel transmission state when a radio circuit is switched and transmitting a spare circuit timing signal to a synchronous switch means after the synchronism is set up for the spare circuit timing. CONSTITUTION:A distribution circuit 11 contains a gate circuit which controls transmission and discontinuation of timing signals distributed to each using circuit and transmits usually no timing signal. When the using circuit is switched to a spare circuit, the digital signals 104 of the using circuit are transmitted in parallel by a control signal 101. Then the timing signal is sent to a synchronous switch circuit 12 by a control signal 105 after the transient due to the switching done by the spare digital signal 103 and then the synchronism is set up. In such a constitution, each using circuit has no fault owing to a step-out caused by a fault of the spare circuit or the transient produced during a switching mode. Thus it is possible to perform the synchronous switching over a wide range of phase differences with no hit nor code error. |
