PCI 5421 frequency sweep issue

[Hideya]

Hi All

   I have a question regarding to PCI 5421 board.  What I need is to sweep the frequency (square wave with 50% duty cycle) from 500kHz to 100Khz in 4000 steps or so.  I have tried this but the board simply does not sweep in such small increment.  What I have found so far is that each time I try to decrease the frequency, I added 4pts.  And this 4pts cost me 40ns each time.  So starting from 500kHz, next step is to go directly to 490kHz rather than 499kHz.  Is the board not capable of producing 499kHz, 498kHz, etc?  When I sweep the frequency using this board by adding sample points, I can get 200 steps in between 500kHz to 100kHz.   Is it possible for me to sweep the frequency using this board from 500kHz to 100kHz in 4000 steps?( 500K, 499.9K 499.8K 499.7K ........100.2K 100.1K 100K)  At the same time, each steps takes only 100microsec or so.  So I can not use function generator for my case.  Arbitrary waveform generator(PCI 5421) can do this?  Thank you very much for the help.

Best

Hideya

[Nick_Storton]

Hi Hideya,

Which ADI are you using LabVIEW, CVI, VB? If you let me know I can probably post an example here for you.

Nick

[Hideya]

Nick

     I have PCI 5421 board and I am using labview 8.  Thank you very much.  

Best

Hideya  

[JerryAL]

Hi Hideya

I didn't realize you were generating square waves.  I'm sorry I didn't realize that, I could have saved you the time you took discovering the issues with generating a square wave using an arbitrary waveform generator.

Please contact Roger Hebert so that I can talk to you on the phone so that I can get the best idea on your application and see what we can do with NI products.

Jerry