time delay between waveforms

[imperial-aero]

Hi,

I've been trying to generate two sinusoids with a time delay between them. I can't seem to get a continuous waveform, possibly due to an incorrect looping. Does anyone know how to accomplish a time delay between two signals ?

Thanks.

[RavensFan]

You are building an array of waveforms which creates a graph of two waveforms.  What you want is the append waveforms VI off the waveform palette.  This appends one waveform to the other.

Also take a look at how you are creating the two waveforms.  You are appending samples for the sample info for the sinewave generation for the 1st waveform, but are adding the extra delay samples to the 2nd waveform's Y array.

[bharath_reddy]

My problem is also somehting like this.Can you tell me how do i get the waveform repeatedly .I think it possible by looping.
Genberating the same waveform with some data contionuously is it possible???

I am attahing my VI,plot and the data input.
Bharath.

[imperial-aero]

Thank you for the reply Ravens Fan. I should have explained a bit more in detail what I was trying to do.

I actually want to generate two waveforms, the original one without delay and the second one with the time delay. What I am really trying to do is generate 8 waveforms, but with a time delay between each one and the time delay increases proportionally between consecutive waveforms. So far I'm trying to test this using two waveforms, and obtaining 8 waveforms should be quite straight forward afterwards.

I am adding the samples (which are all zero) to the Y array of the 2nd waveform to achieve the time delay. The reason why I am adding the number of samples to the sampling info for the 1st waveform is because all analog waveforms generated should have the same number of samples in a single task.

The problem is when I run the VI, I can see the time delay between the two waveforms, but the second waveform does not produce a sine wave after the time delay.


Message Edited by imperial-aero on 04-27-2008 03:16 AM

[RavensFan]

---

imperial-aero wrote:
The problem is when I run the VI, I can see the time delay between the two waveforms, but the second waveform does not produce a sine wave after the time delay.

---

There is a sine wave after the time delay in the second waveform.  You just don't see it because the first wave form lays exactly over top of it.  Create another waveform graph and wire only the 2nd waveform into it.  That, or make the time delay something besides an increment of 0.1 seconds, such as 1.11 seconds.  Then you will see the 2nd sinewave in red.

[RavensFan]

Bharath,

Please don't hijack someone else's thread with your question.  Your question is only barely related to the original poster's.  You should have started a new thread.  And if you want to post a screenshot, please just post the image as a .png.  It is very annoying to have to look at an image that is embedded in a Word document.

What are you trying to do with the waveform you want to generate?  The VI you posted is pretty trivial and doesn't really do anything but read the data file and show a graph.  Yes, you can repeat the same data in a waveform.  You could loop a few times with a For loop (How many times?  You couldn't do this continuously!) and use the append waveform subVI.

Are you trying to generate this waveform on a DAQ device as an analog output?  If so, you just have to set the DAQmx properties to generate continuous samples.

Message Edited by Ravens Fan on 04-27-2008 11:32 PM