acquisition FPGA

[jeanT]

hello !

i've got some problems to understand how to acquire a signal properly, i've got a FPGA 7951R and a module NI5731. I generate a  500 Khz  sinewave with a fonction  waveform generator, and i plug it into the Analogic input 0 of my module 5731. And i would like to see it into a graph on my FPGA ( see picture attached). i understand that the numbers on the Y axe is the number of samples i got, but still don't understand how to manage the timing loop and the number of sample of my graph ( Y axe ) to get the proper waveform at 500 Khz.

Any help ? thx

[David-A]

Try using a timed loop rather than a while loop on your FPGA diagram. You are not generating samples at a regular internval inside of a while loop, but inside of a single cycle timed loop you will. See the 'High-Performance Programming With the Single-Cycle Timed Loop' section that starts on page 15 of the High-Performance FPGA Developer's Guide for an in depth explanation.

The NI LabVIEW High-Performance FPGA Developer's Guide

http://www.ni.com/tutorial/14600/en/

[jeanT]

it's not really better, but for axample, see attached, i acquire a 5Khz signal, and if i put 200us into the count module and if i put 300 samples ( Y axe of the graph) i've got 1 periode but i would like to know if what i see is a 5khz signal or not 😕  i'm trying to find an example of acquiring a signal with the NI5731 module but i don't find any any help ?

thx

[David-A]

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@jeanT wrote:

i'm trying to find an example of acquiring a signal with the NI5731 module but i don't find any any help ?

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There is a getting started example for the 5731 in the example finder. Go to Help>>Find Examples to open the example finder, from there you will want to navigate to Hardware Input and Output>>FlexRIO>>IO Modules>>573x>>5731 and then open the getting started example. 

[jeanT]

hello David,

I know that, but the problem is that i don't have this one ( see attached):smileysurprised:

[David-A]

If you are missing the examples for the IO Modules then you will want to install FlexRIO Adapter Module Support. You can find it by going to ni.com/downloads and doing a search for FlexRIO. Here is a link to the most recent version (4.1) that you can use if you are using LV 2012 or 2013.

NI FlexRIO Adapter Module Support 4.1

http://www.ni.com/download/ni-flexrio-adapter-module-support-4.1/4657/en/