| 摘要 |
PURPOSE:To omit the trouble of operations of a restoration push button by disconnecting a transmission line where noise is detected and by restoring the line automatically when continuous receiving frequency of a set normal code or receiving code non-input over a fixed time is detected. CONSTITUTION:The signal which is received by hybrid transformers H1 and H2 provided on upper or lower working line MLD or MLU is inputted to code decision circuits DT1 and DT2, and switches SW1 and SW2 are opened when the code is decided as noise. Then, switches SW1 and SW2 are restored automatically under conditions of continuous receiving frequency of a normal code, which is set in code decision circuits DT1 and DT2, or receiving code non-input over a fixed time after opening. |
