| 摘要 |
PURPOSE:To select only a data required from each terminal station equipment by sending to amplitude-modulate an information block and a data block. CONSTITUTION:An optical signal from an optical terminal station equipment 2 is converted into an electric signal by an optoelectric conversion section 6 of an optical terminal station equipment 1, and a pulse amplitude demodulation section 7 separates the electric signal subject to pulse width modulation into an information block and a data block. Then the equipment 1 monitors a terminal station number of the information block, a data start address and a data end address to read the data block via a data read section 9. A data demultiplex/insert section 15 receives/outputs the read data and writes the terminal station number of its own station, the data start address and the data end address to the information block. Then a pulse amplitude modulation section 12 outputs the information block and the data block as one modulated block via an electrooptic conversion section 13. Thus, only a required data from each terminal station equipment is selected. |
