| 摘要 |
PURPOSE:To realize the confirmation of the control signal of facsimile with a simple constitution, by measuring the number of incoming pulse or period. CONSTITUTION:After an incoming signal is rejected for noise at a band pass filter 10, it is amplified and converted to a TTL level and fetched to a CPU. The CPU makes the period measurement of an input pulse with the software. As the CPU, that in the facsimile device is used. As the hardware, it can be done only with the one which converts the input signal into the TTL level and the band pass filter can be used only having width of 300-2,500Hz for noise rejection simply, allowing to remarkably reduce the cost of the hardware. |
