Analog In FPGA Rio

[preston_johnson]

Guys, you need to realize that the 9234 is a DSA device and runs on its own internal clock.  Pacing it with a timed loop DOES NOT work with DSA devices.  Please take a look at the reference designs I linked to in an earlier post. 

[TheGeeze]

Hi all,

For getting started with DSA modules, you should check out the shipping examples.  They should be ready to go, and have code written for the FPGA to give you a starting place.  To find the exaple, open up the example finder by going to help > Find examples from any LabVIEW window.  Next, go to Hardware Input and Output > cRIO > Module Specific > 923x Continuous DMA.

Cheers.

Ryan

[preston_johnson]

Thanks for the note Ryan,

The Continious DMA example is illustrative in basic principles.  The Waveform Reference Library builds on these and adds much more:  https://forums.ni.com/t5/Example-Code/Reference-Application-for-NI-CompactRIO-Waveform-Acquisition/t...

It synchronizes the start of acquisition with a time stamp on the RT controller - so you have better t0 accuracy

It increases error handling coverage

It handles varied number of channels on the RT side

It formats the data to a FLOAT on the FPGA side before the DMA buffer - saving 40% of the RT CPU time.  It is expensive to cast from fixed point to float. 

Just another helper to consider