| 摘要 |
PURPOSE:To attain the function of a loop transmitting system although plural faults arise at one time to the transmissing system, by forming a by-pass line to each data communication device and selecting the bypass line by means of a changeover switch. CONSTITUTION:In a normal mode each station is set in a loop mode, and each bias switch is open. Each station includes hardware including a CPU for control of transmission and software. Then either one of these stations is selected as a master station which controls the transmission of the entire system. Thus the selected master station detects a disconnection of the transmission line or a breakdown of either station of the system. If a station 2 has a breakdown, the transmission is carried out after closing the by-pass switch of the station 2. |
