Low sample rate with NI USB-6008

Hello,
We are working on a project collecting data from a hybrid rocket motor for
University research. We are using a NI USB-6008, which has a sample rate of
10kHz. We are using 3 channels and getting a sample rate of ~60 samples per
second. I have attached the VI. Is this slowed by software, or physical
computer computation speed? This sample rate needs to be much higher. Any help
is greatly appreciated.
- Theo
Attachments:
Hybrid DAQ_10.vi ‏73 KB

Hi Rocket 154,
You’ve already had some
great responses, but I just wanted to add a little bit. A great starting point
to writing good code would be the Getting Started with NI-DAQmx: Main Page,
as well as the shipping examples (In LabVIEW, Help » Find Examples) already
mentioned.
If you navigate a bit
through the links (Basic Programming with NI-DAQmx » Getting Started with NI-DAQmx
Programming in LabVIEW) you’ll end up with some great resources. I recommend Learn
10 Functions in NI-DAQmx and Handle 80% of your Data Acquisition Applications.
It will detail many of the functions you can use and give you a feel for proper
code style in LabVIEW.
I hope that helps.
Mark E.
Precision DC Product Support Engineer
National Instruments
Digital Multimeters (DMMs) and LCR Meters
Programmable Power Supplies and Source Measure Units

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Attachments:
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Attachments:
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Thanks
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Attachments:
CoolSnap.vi ‏142 KB

Hello sha33,
Thank you for getting back to me with more information. After looking through your code once more, I believe I have found the issue. Since this application is timed entirely in software, it is based on how quickly your operating system can run the program, and thus cycle through loop iterations. Since you have no Timing VIs in the program, this loop is running as fast as possible. Now, in the 33 ms case, you are getting a TTL edge a lot faster, so the DAQ assistant is updating its count faster as well. Lets say hypothetically that your loop is iterating at 60 ms. This means that every time you run through the loop your DAQ assistant will read the updated count value, and since you are counting every 33 ms, your count value will have updated.
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Oops.. Just realized that this got posted in the Motion Control Forums... Meant for it to go in the MIO forums. Sorry!
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Eric
DE For Life!

Drive higer load with the usb 6008

Hi all,
I need to drive a small motor with the analog output of the usb6008 device ... connecting it directly doesn't seem to work.
Any suggestions how get it working??? what does the 6008 output?
My motor works on a AAA battery dricetly.
Thanks a lot

On Apr 23, 12:40 am, lav21 <[email protected]> wrote:
> Hi all,
>  
> I need to drive a small motor with the analog output of the usb6008 device ... connecting it directly doesn't seem to work.
>  
> Any suggestions how get it working??? what does the 6008 output?
>  
> My motor works on a AAA battery dricetly.
>  
> Thanks a lot
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Attachments:
Temp Pressure EXpress.vi ‏92 KB

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I'am a french user and my english is not good Sorry..
Fabien Palencia
Ingenieur d'etude ICMCB CNRS
"StephenZhou" a ?crit dans le message de news:
506500000005000000A5AF0000-1031838699000@exchange.ni.com...
> Hi, Fabien Palencia
>
> The program is great.
Do you happen to know how to convert the big
> binary file to ascii file? Thanks
[Attachment recup data I16.vi, see below]
Attachments:
recup_data_I16.vi ‏57 KB

Low sample rate with NI USB-6008

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