| 摘要 |
PURPOSE:To attain mutual communication between a transmission/reception circuit and plural order lines by connecting an output of an input amplifier and the transmission side of a desired order line by a selector. CONSTITUTION:Order lines 1-1-1-n are converted into 4 wires via hybrid circuits 2-1-2-n in a terminal station having the plural order lines 1-1-1-n. Further, a receiving side of each 4-wire circuit is amplified in common and its output is led to a transmitting/receiving circuit 11 via a switch S2 and an HPF10. Moreover, the transmission side of the transmitting/receiving circuit 11 transmits a transmitted output to the selector 6 via a multi-input amplifier 5 and transmits it further to the order lines 1-1-1-n via the selector 6 through the circuits 2-1- 2-n. Then, the selector 6 controls the connection by a signal of a signal oscillator 12. |
