Trouble exporting myRIO encoder data; limited to 100 samples/sec

[awlucey93]

Hi everyone,

I'm somewhat new to LabVIEW and myRIO, and I’m trying to read data from a quadrature encoder using myRIO’s encoder reader. In my LabVIEW program, I have the Counter Value terminal of myRIO’s Encoder VI wired to a Waveform Chart, and I run the program in a While Loop. The problem: When I export the Waveform Chart data to Excel, I am only able to get 100 samples for every second that I run the program. I’ve noticed that this problem occurs whenever an I32 or Double datatype is wired to the Waveform Chart, and the Counter Value terminal is of I32 datatype. This problem, however, doesn’t occur when the datatype is Dynamic Data. For example, if I use the Simulate Signal VI and set its sample rate to 10,000 samples/sec and wire that to the Waveform Chart, I’m able to export 10,000 samples/sec. However, I’m not sure how to get the Encoder VI to give me any datatype but I32, and converting this I32 data to Dynamic Data doesn’t solve anything.

Does anybody know a way around this issue?

[Bob_Schor]

Well, looking over the code that you failed to attach (don't bother attaching a picture, zip up your Project and attach the .zip file, please), I can't comment at the present time.  It is very difficult to make suggestions about what a beginner is doing wrong when we have no idea what the beginner is doing at all!  Attach your Project!

Bob Schor

[GerdW]

Hi awlucey,

please read the help for the Waveform Chart, especially the notes on its history. Then change the history size as required...

I recommend not to rely on such features, instead you should write a program according to your requirements!

[awlucey93]

Here is my project.

[Bob_Schor]

Thank you for attaching your Project.  When I opened it with LabVIEW myRIO Toolkit 2019, it "looked like" an ordinary (non-RIO) LabVIEW Project.  Attempting to open the Express VI (grrr -- I still dislike these!), I got a warning:  "The target does not support this Express VI.  Click the Help button to get the information about the targets that support this Express VI".

Before you tackle a (slightly) complex Target like a myRIO, you should learn enough LabVIEW to be able to write code and build projects appropriate to the hardware you want to use.  Learn LabVIEW first, then learn LabVIEW Real-Time.  Learn "simple DAQ" (such as a USB-600x or a myDAQ) first, then move up to a myRIO.

Bob Schor