| 摘要 |
PURPOSE:To smoothly attain data relay and quick loop acquisition with a simple equipment by forming a communication line by an optical fiber, providing a couple of photoelectric converters on each node, juxtaposing the subloop of a similar constitution with the main loop of the constitution to above and using the subloop so as to acquire a loop. CONSTITUTION:Each node has an LAN controller LCT and a terminal control section 71. A loop acquisition signal reception section 55 monitors a back loop 3B when no loop acquisition signal Dc of other node exists, loop switches 49, 51 are switched from the relay state into the acquisition state and its own logic address is sent continuously to the loop 3B. When the logic address in the returned signal Dc is coincident with its own logic address, the loop acquisition is finished. When the loop acquisition is successful, the reception bit in the signal Dc is set prior to the transmission of a frame and the signal Dc added with its own address number is transmitted continuously. The signal Dc flows through the loop 3B, is received by the reception section 55 of other node and all other nodes enter the reception state. Then the frame transmission to the main loop 3M is started and after the end of transmission, the switches 49, 51 are thrown to the position of the repeater side. |
