| 摘要 |
PURPOSE:To simplify the line switch control system of a spare system by connecting switchingly a modulator and a demodulator of an analog signal and a digital signal to each of transmission input and reception output of a spare line. CONSTITUTION:An active analog signal is given to two systems comprising oscillators 10a,10b, transmitters 5a,5b, receivers 6a,6b, demodulators 2a,2b and signal detectors 12a,12b and an active digital signal is given to two systems comprising modulators 3a,3b, transmitters 5d,5e, receivers 6d,6e, and demodulators 4a,4b. A spare analog signal modulator 1c via distributors 7a,7b, switches SW-1,SW-2, a spare digital signal modulator 3c via distributors 7c,7d and SW-3,SW-4 and a spare transmitter 5c via an SW-A are connected between the transmitters and receivers. a spare receiver 6c is connected to spare analog signal and digital signal demodulators 2c,4c via an SW-8. If an active line is faulty, it is detected by digital and analog line switch controllers 18,16 and informed to devices 17,15 to switch the line to the spare line. |
