NI-9253 DAQ Assistant Skips half second or so in all read modes

[jacobroschak]

Howdy Folks, 
I know most of you are going to ask to see a VI. At this point I'm so perplexed the VI holds only 1 DAQ Assistant reading channel AI0 wired to a Waveform Chart. I can't figure out why it seems to skip a half to a full second between samples when running in continuous mode (anywhere from 25k to 100Hz sample rate) and being the only thing in the VI, it shouldn't  be waiting on another task/operation. I haven't leapt deep enough into LabView to know how to write my own SubVI for DAQ assistants, and the times I've tried have led to more failures than gains. If anyone has any ideas/tips, I would be very grateful. 

[jacobroschak]

Upon further investigation, it looks like the Task is starting and stopping in between iterations, as TDMS logging has multiple different groups over one 10 second run period. Something I had thought wouldn't occur with continuous mode (and I believe was the case when I wrote a test program last year), and had read in many forum posts. I really am at a loss with this. 

Thanks,

Jacob

[RavensFan · Accepted solution]

Attach your VI.  What you think you programmed and what you actually programmed may be two different things.

Look at Help >> Find Examples ...   For DAQmx examples so you can get rid of the DAQ Assistant.

You can also right click on the DAQ Assistant and pick Open Front Panel.  That will convert it to a regular subVI and drill down to see the underlying code that uses real DAQmx functions.  Then you'll learn how it actually works.

[jacobroschak]

Thanks for the advice, I ended up going Task->DAQ read-> data out, and it works, I'm still not sure why it was giving me problems, but I don't need to worry about it for now. I'm not sure how perfect it is, and in setting up the task in NI Max, I still feel like I'm using a DAQ Assistant, but hey, it's less finnicky!