Line concentration device for duplicated loop type local area network

Abstract

Abstract PURPOSE:To avoid a fault from giving adverse effect onto the entire network by surely bypassing a signal even if the fault takes place not only in a transmission line, but in other places. CONSTITUTION:If a fault such as an open optical fiber cable L occurs, no pilot signal is given to control circuits 16(16a, 16b) of optical repeaters 2(2a, 2b). It is detected by a control circuit 16 and the signal is bypassed in the inside of the control circuit 16. If the circuit itself of the optical repeater is faulty and the power supply is interrupted, it is detected by a power monitor circuit 18(18a, 18b) and a switching control signal is outputted to switch sections 36(36a, 36b) and 38(38a, 38b) of a metal relay section 4. Thus, the transmission signal is bypassed by the switch section. Moreover, if the circuit of the repeater 4 is faulty, since it is the same as no input of switching control signal from the monitor circuit 18, the connection of the switch sections 36, 38 is switched. Thus, the signal is surely bypassed even if a fault takes place at an arbitrary place.

Inventors

• 👤 Hiroshi Ishihara
• 👤 Masahiko Hori

Bibliographic Details