Frequency measurement whit NI 9401

[Skyfiller]

Hi, i'm new in to this forum, i'need some information about how to calculate frequency acquired by Ni9401.

I see the signal, and the measured value in the " My frequency Task", but i'don't know how to calculate the frequency using the metod of 2 counter (Large Range), the formula in the help say :

Frequency = divisor/ measured period      What's measured period? Where i can find it?

An other couple of things, when i measure the same signal using the 1 counter(low frequency) metod, any value is show in "mesured value" box, and when the timeout is passed appear a message of error. What can be the cause?

And usig this metod whit 1 counter, for calculate frequency i need the counter timebase rate... where i can find it?

Thank for help, and sorry for english if is not perfect.

[LiciaP]

Hi,

at this link you can find a tutorial describing the three different methods to measure frequency with counters.

However, you won't have to worry about formulas or parameters, as you simply have to select the proper method, make the correct hardware connections and DAQmx will do all the rest: the measured value shown in the task is already the signal frequency in Hz.

I hope this helps.

Bye!

Licia

[JB]

Some more links to examples, discussions...