| 摘要 |
PURPOSE:To reduce the cost and to decrease the occurrence of a fault. CONSTITUTION:The system is featured that the master station 1 is provided with a couple of transmission reception circuits, a transmission changeover means 71T connecting each optical fiber link, a reception changeover means 71R, a transmission line selection means 8T discriminating transmission destination slave stations 21-23 for a transmission data at the data transmission from transmission reception circuits 41T-43T and selecting the transmission changeover means 71T to select an optical fiber link to the discriminated transmission destination slave station, and a reception line selection means 8R selecting the reception changeover means 71R to select the optical fiber link in which a reception data from the slave stations 21-23 is in existence at the reception of data by the transmission reception circuit or a reception line selection means 8R to select the reception changeover means 71R to select optical fiber links 31R-33R in interlocking with the transmission line selection means 8T at the reception of data in the transmission reception circuit. |
