| 摘要 |
PURPOSE:To enable the data transmission with high reliability with a simple circuit constitution, by connecting both end points with the bus control unit provided at both end points of the information bus provided in ring shape at open wire of the information bus. CONSTITUTION:At normal state without open wire, the bus control unit 11 opens both end points A, B of the information bus 1 to form one bidirectional common transmission line taking the A, B as the end points. Next, if open wire is caused at the part X of the information bus 1, the bus control unit 11 connects the A, B of the information bus 1 to form one straight line bidirectional common transmission line taking the failed point X as both end points. Accordingly, since one straight line bidirectional common transmission line accessible from the entire data station 2b can be formed both for normal and failed modes, the mutual communication between arbitrary data stations can be made. |
