How to measure the 12M frequency squarewave using NI DAQ PCIe 6363?

[FloatStone]

Hi, guys,

Sorry for my poor knowledge.I want to measure the 12M frequency squarewave using NI DAQ PCIe-6363. And I want the resolution should up to 1HZ.

I tried to use the counter,to measure this high frequency, I tried the "High frequency with two counters". I used the example to measure(attach below), in order to increase the resolution, the "measurement time" was set to 1s, and the "sample" value was set to 1.Shown as below:

Meas Dig Frequency-Buffered-Cont-High Freq 2 Ctr.vi

Right now,yes, it works.It can measure the frequency, but the resolution is too low, only 100HZ, is it possible to increase to 1HZ?

Right now the vi using the internal 20M timebase.Here is the question:

1. How to use the 100M timebase? I've tried to config the timebase before the "implicit", the vi can run,but no change comparing to the example.

Frequency Tester.vi

2. How to calculate the frequency resolution?

Thanks very much.