Measure EVERY period of a 6kHz square wave for 1 minute with DAQmx

[ranger]

I am attempting to measure the period of a 6kHz square wave.  I need to make sure I measure every period as I am looking for slight changes in the period, which will be post-proccessed after collecting the period data.  Total recording time is expected to be about 1 minute long.  I was planning on recording this data to a binary or TDMS file.   It appears that I am only recording a fraction of the period values that I am expecting.  I have the output of a function generator (simulating my actual device) connected to the PFI8 (pin 37) and D Gnd (pin 36) of my PCI 6220 M series DAQ board.  I have been looking at the examples such as: 'Count Digital Events-Buffered-Continuous-Ext Clk.vi'  What should I have the 'Measurement Time' and 'Number of Samples' set to if I plan on a signal around 6kHz?  Overall signal range would be 1kHz to 10kHz.   The example states an external sample clock is required...what is this and what pins should it be connected to?

Thanks for your help,

Steve

[aNIta B]

Hi Steve,

        It sounds like you might want to check out the example, "Meas Pulse Width.vi" for your application.  Here, you can input your minimum value of .0001 and maximum of .001 since you are going to be between 1 to 10kHZ frequency.  In this example, you won't need an external sample clock.  Let me know what you think. 

aNIta B

Applications Engineer

National Instruments