Hi Ryan,
Since you are trying to measure the frequency or period of a series of digital pulses, I would suggest using the counter/timer capabilities of your board.
LabVIEW has many example programs included in it (including several examples that do what you are looking for). You can get them by going to Help >> Find Examples >> Hardware Input and Output >> DAQmx >> Counter Measurements >> Digital Frequency
Here you will see several examples, choose whichever one looks like it will work best with your application. I would also suggest trying a couple different ones to get a feel for how they differ. Also, take a look at the code to see how it operates.
Thanks,
Sal