| 摘要 |
PURPOSE:To detect deterioration of a light signal due to loosening, etc., of an optical connector in its early stage by using a microcomputer and an integrating circuit for detecting the pulse width of a diagnostic code. CONSTITUTION:The light signal sent from an opposite device Y through an optical fiber 3 is inputted to a photodetecting circuit 6 through a connector 4 in a receiver 5 and converted into an electric signal. A microcomputer 7 supplies the communication code signal of the electric signal to a load 7a and once the diagnostic code is detected, a gate 8 is opened for a period corresponding to the diagnostic code to input the diagnostic code to an integrating circuit 10. The integrating circuit 10 integrates code pulses in the diagnostic code period to charge a capacitor C accordingly. when the voltage of the capacitor C exceeds a prescribed value, a comparing circuit 11 detects the pulse width of the diagnostic code being normal to send a detection signal to the computer 7. When this detection signal is not received during the diagnostic code period, the computer 7 decides deterioration of the received signal to drive a warning circuit 12. |
