Two Sampling Rate issues

[EggEggington]

Hello everyone,

I'm still a beginner to Labview and I'm trying to set up a VI with 8 sensors, with two groups of those sensors measuring at 2 different sample rates. My current issue is that whenever I try to write to an LVM file, the delta-x values are wrong, where one group will show the correct sample rate, while the other will show a slightly different sample rate to the rate that was actually set set.

I'm not sure how to fix this issue, and if possible, I'd like to know how to set up the data to have 1 time column instead of having each channel having its own time column, where the slower sample will have duplicated values across the time values where a new sample wasn't recorded?

I have a version "in pieces" (3sensors1file) and one using DAQ assistant, but they both have the same issue, so I attached both, with an example LVM file from 3sensors1file. If needed, I'm using a cDAQ-9174 with modules NI 9232, NI 9233, and NI 9237. Warning that this VI is for version 2016!

Thank you in advance!

[EggEggington]

Hello everyone,

I'm stilll new to Labview and have been having trouble with writing measurement files when using two different sample rates with two different groups of sensors. When run the code and look through the LVM file created, according to the delta x values I get different sample rates than the ones I set. Warning in advance that my VI is the 2016 edition, and that I'm using the cDAQ-9174, NI 9237, NI 9233, and NI 9232. I have an example Excel file and my VI attached. Thank you in advance!

[GerdW]

Hi Egg,

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@EggEggington wrote:

I'd like to know how to set up the data to have 1 time column instead of having each channel having its own time column, where the slower sample will have duplicated values across the time values where a new sample wasn't recorded?

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In your VIs both sample rates are set to the same values…

When you need a different file format then you should not use that ExpressVI to save the data: create your own VI for that purpose.

Or switch to TDMS: this will save separate channels/groups with their own properties more easily!