摘要 |
<p>The relay device includes a first switch interposed between a first extraction unit and a second superimposing unit and a second switch interposed between a second extraction unit and a first superimposing unit. The first switch opens and closes a path where a superimposed signal is relayed from a first transmission path to a second transmission path. The second switch opens and closes a path where a superimposed signal is relayed from the second transmission path to the first transmission path. The first switch is controlled in response to reception of a first control signal to be turned off when a superimposed signal is relayed from the second transmission path to the first transmission path. The second switch is controlled in response to reception of a second control signal to be turned off when a superimposed signal is relayed from the first transmission path to the second transmission path.</p> |