| 摘要 |
<p>PURPOSE:To secure data transmission even if an optical transmission line is damaged by providing the titled network with an optical transmission line for connecting respective local stations(LSs) with a master station (MS) like a loop, individual radio communication means between respective LSs and the MS and a backup optical transmission line connected between the LS incapable of radio communicating and the MS. CONSTITUTION:The master station(MS) 12 is connected to respective local stations(LSs) 13-1-13-4 through optical fibers 14 consisting of two cores like a loop, respective LSs 13-2-13-4 are connected to respective radio transmitters 15-1-15-3 and the MS 12 is connected to radio receivers 18-1-18-2 corresponding to the radio transmitters 15-1-15-3. The LS 13-1 is arranged in an engine control room and a backup optical fiber 19 consisting of two cores is connected between the LS 13-1 and the MS so as to be used only when radio communication is disabled. The optical fiber 14a is usually used for data transmission between the LSs and the MS, and when the optical fiber 14a is damaged, data transmission is switched to the optical fiber 14a. When damages g1, g2 are generated on the fibers 14a, 14b for instance, a loop circuit is formed by the optical fibers 14a, 14b among the MS 12 and LSs 13-1, 13-3, 13-4, but the LS 13-2 is disabled to execute data transmission ased upon the optical fibers 14. At that time, the impossibility of data transmission is detected and the radio transmitter 15-1 is driven. When damages g3, g4 are generated on the optical fibers 14a, 14b on both the ends of the MS 12, connection between the MS 12 and the LS 13-1 is switched to the fiber 19 and radio transmitters 15-1-15-3 are driven.</p> |
