| 摘要 |
PURPOSE:To detect simply and assuredly the collision of communication, by detecting the peak amplitude of a communication digital signal on a bus line and at the same time, counting the changing number of times of the detected peak value, and assuming as the collision of communication occurs when said changing exceeds a prescribed level. CONSTITUTION:When a collision of communication arises on a bus line to increase the signal peak value, the voltage higher than the voltage VH held by a capacitor 6c is applied to an amplifier 6a as shown in a figure (a). As a result, the voltage equivalent to the difference of potential is applied between input terminals of the amplifier 6a. Then a waveform shown in the figure (b) is produced at the output terminal. The received signal which is detected by a peak detector 6 is applied to a peak state change detector 7 via a buffer amplifier 8. The detector 7 supplies the peak voltage to a comparator 7c via a differentiating circuit consisting of a capacitor 7a and a resistance 7b and then supplies the output to a counter 7d. When the counted value of the counter 7d exceeds a prescribed level, the output of the counter 7 can be used as a communication collision detecting signal. |
