Hi, for my application need to acquire a Square wave whit a myRIO 1900, and measure the frequency of it. The frequency of my signal is around 20kHz,but the frequency can vary by about 10 Khz depending on the crystal conditions. During this variation I should be able to appreciate the variations of the HZ.To read the frequency I made a counter in fpga, see fig1., From which I get the period of the signal which I then convert to frequency (1 / P) in vi real time. The problem is that by varying the frequency, the reading precision is in the order of 100hz. How can I increase the accuracy until I appreciate the variations of the HZ? Thanks David

LabVIEW

Frequency Measurement in FPGA

use the counter to timestamp the first (resp. the last of the previous measurement) and the last edge. In that manner you can increase the timing accuracy . Method 3 in the link about freq measurement.

Greetings from Germany
Henrik

LV since v3.1

“ground” is a convenient fantasy

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