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The upper right plot is the measurement error after applying the corrected on-board 20MHz clock rate to the data.
Lower left is a plot of various measurement errors. The top black points are the frequency discretizaion due to a difference of one 20 MHz clock tic. As you can see, above 200 KHz input frequency the resolution is coarser than 1 part in 106, which is the target accuracy for sampling the ParoScientific 202BGs.
*max(abs(fcor-fref))*is the maximum absolute difference of the measured, clock corrected frequency from the reference frequency for the 100-300 samples at each reference frequency. This maximum error seen in the test stayed below the 1:106line except for some points at frequencies over 200 KHz. The maximum error also generally stayed below the frequency discretization level, suggesting that after the clock is corrected, almost all of the remaining error is due to the discretization.
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