| 摘要 |
PURPOSE:To easily identify whether the cause of detected error exists at an optical data part or at an electric data part by providing a return circuit for signals at the electric data part as well. CONSTITUTION:When there is no error as the checked result of a data generation/check circuit 1, it can be judged that this data transmission system is totally normal. When any error is detected in this total return data transmitting function test, the output of a branch circuit 7 is switched by a selecting circuit 8 and connected as the input of a decoding circuit 6. An electric/optical conversion circuit 3, optical fiber cable 4 and optical/electric conversion circuit 5 are excluded from the return circuit by this connection, and the return data transmitting function test at the electric data part is performed. Therefore, it can be easily identified whether the cause of the detected error exists at the optical data part or at the electric data part without complicating the system, and time for fault investigating and analyzing jobs can be shortened. |
