FPGA Sampling problem

[jeanT]

hi everybody,

i have a problem with timing on my FPGA,  i would like to acquire a signal at 400khz, and the  analogique/digital converter( NI5731) is working at 40MS/s, so one period of my sinewave should be described by 100 points, but what i see ( picture attached) is that one periode is described  with 23 points. So it seems like the analogic signal  is not sampled at 40MS/s as it should be. Any help ?

Thank you !

Regards

Jean

[jeanT]

here are some pictures of my code

[Jérôme.H]

Hello jeanT !

You should do like in this example, you have to use a timed loop, with "IO Module Clock 0" on the input clock of this loop.

You can find some basics examples here :

C:\Program Files (x86)\National Instruments\LabVIEW 2013\examples\FlexRIO\IO Modules\NI 573X\

Don't hesitate if you have more questions,

Best regards,

[jeanT]

hi jerome !

Tank you very much for this answer i will try to follow the logic of your picture, i don't have the NI 573x example in my computer 😕 could you send it to me please ?

Best regards

jean

[jeanT]

for your information, i'm using Labview 2011

[Jérôme.H]

Et voilà !! 😉

It should open in LV2011

Best regards,

[jeanT]

Thk you very much jerome ! infortunately, the version is still 2013 and labview 2011 can't open it 😞

[Jérôme.H]

Yes, unfortunately I can't easily give you those examples beacuse of FPGA toolkit version..

But here you go for FPGA vi

Regards,

[jeanT]

thank you very much ! but i don't have the "data edge trigger.vi" 😕  so i can't run it

i've got also another question, my aim is to filter the signal that i'm going to acquire, as the butterworth filter is not supoorted into a single timed loop, i got the idea to procede by a FIFO, see attached, but there is a timing problem i presume because the graph don't display the waveforms fluently  😕 it stay freeze.

Thank again !!!!

[jeanT]

ok i found the probleme ! no worries 😉 but i still have the problem with the "data edge trigger.vi"