| 摘要 |
PURPOSE:To shorten the measuring time by setting a communication error ratio P2 which is larger than a communication error ratio P1, measuring the amount of received light S2 of the optical data link on the receiving side when the error ratio is P2, and operating the amount of received light S1 based on the error ratio P2, the amount of light S2 and the error ratio P1. CONSTITUTION:A transmitting circuit 10 is operated with a computer(CP) 30. Optical data are outputted through a transmitted data link 5. The optical data are received with a receiving circuit 20 by way of an optical fiber 4, a variable- light attenuator 3, an optical fiber 2 and a receiving data link 1. The data are compared with the data without errors in a comparing circuit 23. Then, the number of disagreements is counted in a counter 24. In the CP 30, a communication error ratio P1 is obtained based on the output of the counter 24. Then, in the CP 30, the amount of the received light is decreased through the attenuator 3, and the amount of received light S2 when the communication error ratio is P2 is obtained. Then, in the CP 30, the amount of received light S1 is obtained based on the error ratio P2, the amount of light S2 and the error ratio P1. |
