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Using Signal Express VI for DAQmx, timing & file size issues

I am using a Signal Express VI with my DAQmx. Long story short, my DAQmx VI's don't work in LV 8.6 (possibly IT installation error). I have a few issues (I'm a beginner so be easy).

 

First, I'm confused on how to get the timing correct. I am trying to read a 100 samples (2 channels) average them and repeat this at 30Hz and record this data.

 

Second, everytime I open the Signal Express VI (in my block diagram) and change sampling for example, click OK, then save my VI before running my program. I noticed the file on disk increased in size by the megabytes! All I changed were the sampling settings.

 

I appreciate any input, thanks in advance!

 

-Michal

 

 

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To your first concern, it sounds like DAQmx was installed before LabVIEW.  Just reinstall DAQmx and it will work fine in LabVIEW.

 

For you second concern.  To get 100 Samples at 30 Hz, you will need to change your channel setup in signal express.  You will need Continuous Aquisition, with 100 Samples to Read at 3000 Hz.  Then you code should work as expected.

 

Chris Bakker
SET Americas
CEO

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Great! Thanks for your help! I will try this on Monday as I'm off today. I'm still baffled about the Signal Express VI, increasing my program in size by the megabytes (when making any change in it)! I will also have our IT install DAQmx over again since it looks like its completely missing since they last upgraded to 8.6 from 8.5.

 

 

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