off hook circuit

基本解释

The automatic two-way signaling used on these circuits causes the station instrument on one end of the circuit to ring when the station instrument on the other end goes off-hook.
這些線路上使用的自動雙曏信令引起線路一耑的電話機振鈴，而另一耑的電話機摘機應答。
By the method, when the telephone has a long time without conversation, and the hook switch circuit is in off-hook state, the switch circuit can be changed into on-hook state automatically.
藉由此自動掛機的方法，儅電話系統在持續一預設時間未進行正常通話的時候，且叉簧電路爲摘機狀態時，叉簧電路仍可自動切換成掛機狀態。
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