| 摘要 |
PURPOSE:To prevent the trouble of one subordinate station from disturbing information transmission to other subordinate stations by providing repeaters, to which subordinate stations are connected, with methods of passing transmitted information as it is to a transmission line when the information has not relation to the subordinate station. CONSTITUTION:On light transmission line TL, repeaters STE are arranged and to each of them, a master station or subordinate station is connected. Through photoelectric converter O/E, transmitted information is sent to STE and then input to a subordinate station via FF. To FF, a through circuit including gates G4, G5, etc., is connected. While a subordinate station sends no information, the inversion signal of signal BPS is held at level H, G4 is open and the output of inverter In is at level L to open G5. Further, the output of inverter In is at level L, G5 is open, and consequently the transmitted information, amplified by STE, reaches electro-photo converter E/O by way of the through circuit (G4 and G5) and converted into a photo signal, which is transmitted to the transmission line. Therefore, no influence of the equipment state of a subordinate station is exerted. |
