| 摘要 |
PURPOSE:To restore quickly a failure by obtaining the delay time of a reflected wave from a bus failed position to a transmitted wave to detect a bus failed position. CONSTITUTION:In starting communication from a terminal 5 to a terminal 11, the terminal 5 transmits a pulse for detecting bus failure to a cable 1 to check the state of the bus cable 1 and the pulse is received by a pulse failure position detector 4. If no failure exists in the cable 1, no reflected wave is generated and the detector 4 receives the transmitted wave only and does not receive the reflected wave. On the other hand, if a failure exists on the cable 1, the transmitted pulse is reflected at the failed position and detected by the detector, allowing the detector to calculate the distance from the terminal 5 to the bus failed position based on the time from the receiving of the transmitted pulse to the receiving of the reflected pulse. Thus, the bus failed position is detected to prevent malfunction and the failure is restored quickly by offering the failure position information. |
