| 摘要 |
PURPOSE:To transmit signals of plural kinds by transmitting n-kind of digital signals not being true at the same time through a single optical fiber line. CONSTITUTION:Only one of inputted digital signals S1-S3 is at H level (true) at all times at the reception side. When the signal S1, e.g., is at H level, an AND gate 21a is in the permissible state, a carrier clock signal in a frequency f1 from a clock generator 20a is outputted as an AND output S1.C1 and given to a digital optical transmitter 23 via an OR gate 22. The transmitter 23 transmits an optical signal in response to the signal C1 obtained at the H level of the signal S1 to an optical fiber line 24 and a received reproducing signal having the frequency f1 is obtained by a digital photodetector 25. Thus, plural kinds of signals are transmitted through the single line 24, the reception side is digitized entirely and the circuit is operated stably. |
