Spectrum Analyzer using Swept Frequency

Question

Using the AWESOM example foundhere:
http://zone.ni.com/devzone/explprog.nsf/6c163603265406328625682a006ed37d/433c2cbc5a1c4a49862569500035f715?OpenDocument
Give the person who wrote that an A+. I want to replace the FIR filter with a REAL device. I want to send a swept sin wave (just like the original) and then read the response from the Analog Input channel. I put a vi in place of the vi called :IIR Filter for 1 Chan.vi. Go to the NI ftp site to ge t the file named ZZDMKSin.zip (I could not get the file attachment to work within this post) The symptom is the Frequency Response does not get any data that can be seen...
In the end I simply want to put a REAL UUT in place of the FIR filter. This would turn the VI into an equi
v of a $30,000 spectrum analyzer! Sooooo cool!
Any help would be greatly appreciated. My e-mail is [email protected]
Thanks,
Dave

Answer 1

Dave;
I'm not quite sure if I understood your application, but by my understanding you want to replace one of the Filter VIs by a VI that does data acquisition from a real external device.
The first thing you might want to double check is the data acquisition VI by itself. Set up the system with the external device and with the data acquisition VI only. Make sure the VI is acquiring data as expected.
After that done, make sure that the data acquisition VI output is outputing the same data type that is expected at the output of the IIR Filter.vi.
I believe that either one of the previous issues might be the answer.
Hope this helps.
Filipe A.
Applications Engineer
National Instruments