Problem measuring frequency with PXI-4472 module

[Avasarala]

Hi all,

I am using PXI-4472 DSA Module to analyse the Frequency.

I am using LAbVIEW 7 software.

I am using the Spectral Measurement VI in Signal Analysis in Functions.

Using that i am not bale to measure the frequency more than 500Hz.

My card is able to measure upto 50KHz.

why it is happening?

what i need to do if i want to measure the frequency upto 50KHz?

regards

Preetam

[gaving]

Hey Preetam,
The Spectral Measurements VI is neat to use, however it is not using the full capabilities of the DSA Board. When you install NI-DSA you will have several examples to help you see how to get the board to do the Frequency analysis for you (without using the Spectral Measurements VI). Try running "NIDSA Getting Started with Baseband FFT.vi" and see if you can get frequencies over 500Hz. The VIs specially made for DSA are located under ALL FUNCTIONS>>INSTRUMENT I/O>>INSTRUMENT DRIVERS>>NI-DSA. These will get the "full" functionality out of your DSA board. (if you don't find them, download and install NI-DSA here http://digital.ni.com/softlib.nsf/webcategories/85256410006C055586256BE600709124?opendocument&node=132060_US

Have fun!

[Jack_A.]

Actually, NI-DSA only works for the NI-455x devices. It will not work on a NI-4472. The NI-4472 uses Traditional DAQ or DAQmx to acquire data.

[Jack_A.]

What happens when you try to measure a signal more than 500Hz? What does the time domain signal look like? How fast is the NI-4472 sampling? Are you using a sensor such as a microphone? Or are you just making voltage measurements?

I would recommend starting on the acquisition side with a shipping DAQmx example such as "Cont Acq&Graph Voltage-Int Clk.vi" which can be found through the LabVIEW Example Finder under the DAQmx section. You will need to have at least NI-DAQ 7.1 to use DAQmx with the 4472, but it's always good to upgrade to the latest version. Here's a link which shows the latest versions of DAQ on a per device basis:
http://www.ni.com/support/daq/versions.htm

Once the time domain data looks good, then try to add the signal processing.

Let me know how it goes.
-Jack