| 摘要 |
PURPOSE: To prevent a transmitter and a receiver at different data speeds from being erroneously connected. CONSTITUTION: The transmitted data at the speed of a clock CKT at a transmission set frequency are received through an optical fiber 4 to a receiver 20. The frequency component almost equal with a clock CKR at a reception set frequency is extracted from the received transmitted data by a BPF 8-2 and its power level is detected by a level detector 8-3. When that power level does not reach a prescribed level, an alarm is issued and wrong connection is displayed. |
