| 摘要 |
PURPOSE:To attain bidirectional communication by transmitting bidirectional signals between respective master equipment having wide directivity, intermediate directivity and narrow directivity as the transmitting medium with light beams, and plural slave equipment through a relay line. CONSTITUTION:Respective kinds of codes inputted in a slave equipment 13 are converted into optical signals corresponding to the codes in a light emitting element driving circuit, and they are received in a light receiver in a master equipment 7, whereby demodulation decoding is performed. The master equipment 7 transmits a transmission instruction signal, which is transmitted to the slave equipments 11-14 through an intermediate directional master equipment 5, a narrow directional master equipment 6 and wide directional master equipments 7 and 8. The optical signals corresponding to a response from the master equipment 14 is received in the master equipment 8 and they are supplied from the relay line 9 to the wide directional master equipment 7. Thus, bidirectional communication between respective slave equipment and respective master equipments 5-8, and bidirectional communication between respec tive slave equipment and a line controller 10 apart from bidirectional communication between respective slave equipments 11-14 are attained, as well. |
