Simultaneous analog output 1k sine wave and data acquisition

Although many topics of simultaneous analog output and input can be found in NI Developer Zone, I have not found a case similar to my project. I'm trying to generate a 1kHz sine wave by using the analog output of NI DAQPad-6070E, and acquire one channel input signal simultaneously. I found most of the examples can not work properly above 100Hz. Any suggestions are welcome. Thank you.
Jian

I have sucessfully solve the problem when I observed the increase of
scan backlog number. Simply increase the buffer size of AI/AO and you
can make the 1kHz sine wave output and data acquired properly.
On Tue, 3 Feb 2004 09:03:07 -0600 (CST), jujian wrote:
>Although many topics of simultaneous analog output and input can be
>found in NI Developer Zone, I have not found a case similar to my
>project. I'm trying to generate a 1kHz sine wave by using the analog
>output of NI DAQPad-6070E, and acquire one channel input signal
>simultaneously. I found most of the examples can not work properly
>above 100Hz. Any suggestions are welcome. Thank you.
>
>Jian

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Simultaneous analog output

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Message Edited by awais.h on 03-30-2010 11:20 PM
Message Edited by awais.h on 03-30-2010 11:21 PM
Solved!
Go to Solution.

Hi
Thanks for the code but I'm afraid it won't work. Like you said the probability of choosing a value that is on both graphs may not happen. This is something that I would like the code to do automatically.
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Show us what you did.
LabVIEW Champion . Do more with less code and in less time .

Does anyone know how to display (in LabVIEW) the memory use during execution of an image and data acquisition VI to predict when it is time to cease the acquisition to prevent the program crashing?

Does anyone know how to display (in LabVIEW) the memory use during execution of an image and data acquisition VI to predict when it is time to cease the acquisition to prevent the program crashing?
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new_control_and_acquisition_program.vi ‏946 KB

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Product Expert
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Attachments:
Cont Gen Voltage Wfm-Int Clk.vi ‏54 KB

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Message Edited by Dennis Knutson on 10-28-2008 08:23 PM
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Record_M8viaDAQv3.vi ‏237 KB

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Saint
"Kevin Powell" ha scritto nel messaggio
news:[email protected]..
>
> I am a Labview user who would like to capture video and data (from one
video
> camera and 4 strain gauges) simultaneously, then be able to play the video
> whilst being able to process the data streams. Is there a simple way to do
> this? - Thanks!

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Phaseshift_Sqr_Sin.vi ‏89 KB

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A schematic picture is attached.
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Attachments:
daq_printscreen.GIF ‏45 KB

siva0182 wrote:
Find attached the picture of the vi where I tried to put in timers.one in each of the frame and at the end added one more frame just to measure the time elapsed .
The last frame and the frame with sourcemeter measurment show adifference of about 140 msec.
Is there any way to improve the speed of this portion?
Probably not. It sounds like the Keithly VI is taking 140 msec. You can try opening that up to see if there is anything in there that could be causing an unnecessary slowdown. But trying to tighten it up too much may cause occasional errors (such as timeouts) in trying to get a response back.
But surprisingly I tried displaying the actual timer value at the start and at the start of sourcemeter read function ..but the display of both indicators is almost equal with little difference of only 10 msec.????? I'm not sure which of the several timers you are referring to here. What is the value going into the wait function between the VISA write and the Keithly VI?
When you do benchmarking, the timer functions should be in a frame all by themselves. Having it mixed with another function or VI causes a bit of uncertainty as to when the time was taken. For instance, you dont' really know if the Keithly VI was started before the time was taken or after. (The time was probably taken first, but without a data flow or sequence structure dependency, you can't be sure.)

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Attachments:
Read Measurement.PNG ‏44 KB
Read Measurement.PNG ‏44 KB

Instrument communications via serial, USB, Ethernet, GPIB, etc just tend to be slow. The instrument has to interpret the data, react to it, and then send data back. That takes time. A few ms per measurement is quite normal. One option you might have is you could tell the instrument to take several measurements and then request all of the measurements once it is done. I haven't looked into the E4980A yet to see if it can do that.
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Simultaneous analog output 1k sine wave and data acquisition

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