| 摘要 |
PURPOSE:To obtain a signal transmission system which facilitates the control of transmission line switching by connecting stand-by transmission lines in a loop when an in-use transmission line is used, and transmitting a signal by using stand-by transmission lines except a stand-by transmission line in a fault occurrence section if one of stand-by transmission lines becomes faulty. CONSTITUTION:When the number (n) of stations is fours, 1-4 are in-use transmission lines used normally among the stations, 5-8 are stand-by transmission lines among the stations, and 21-24 are switch circuits of the respective stations. The in-use transmission line 4 is used normally between stations 11 and 14, but if the in-use transmission line 4 becomes faulty, relays of switch circuits 21 and 24 of the stations 11 and 14 are only changed over as shown by dotted lines so as to recover the in-use transmission line 4 by using the stand-by transmission lines 5, 6, and 7 forming another route. When other in-use transmission lines 1, 2, and 3 becomes faulty, relays of switch circuits of two stations are changed over to recover the faulty in-use circuits. |
