Storing multiple Sine waves in one LVM
Hi all,
actually i got a very short question. I can't believe that i'm unable to fix the problem by my own... But that's the way it's suppose to be I think.
The question:
Just a simple Sine wave in a while loop, connected to a graph. When I run it i see a lot of different Sines in the graph window, let's say 100 sine waves. How can I write this data from ALL THE 100 SINE WAVES to 1 LVM?
When i store the data right now I only see 1 Sine Wave and not all the waves i've seen in the graph window.
I hope somebody can help me with this. Cause this is just a simple example of a very complicated programm i'm working on.
Thanx for spending time on this stupid problem!
Could you post your VIs? I am not sure what you are talking about.
Thanks,
Bob Young
Bob Young - Test Engineer - Lapsed Certified LabVIEW Developer
DISTek Integration, Inc. - NI Alliance Member
mailto:[email protected]
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"Hello everyone, I hope someone can answer the following question. How do I generate a sequence of different waveforms, with different attributes?
Like, i want to generate a sine wave for some time, then a square pulse of some width and then again a sine wave of some other time. Finally I want to repeat this sequence. I'll really appreciated it if I can get an answer soon. Thank you!From the previous comments I am assuming that your waveforms are arrays, rather than the waveform data type. I am also assuming that the sine waves on both sides of the square wave are the same signal.
If so then I suggest a slightly different approach. 1. Generate your sine wave, rather than the empty array. The length should be the length of the entire end signal.
2. Generate the square waveform. You can either generate it at the length you need, or you can generate a much larger square wave, and then use the Array Subset VI to get the portion you need. Which method you use depends how you want to implement the whole method.
3. Use the Replace Array Subset VI to place the portion of the square wave at the location (index) of the original sine wave you ge
nerated.
The result of this method will be an array that starts with your sine wave, and then at the index you choose it will place the square wave of the length you want right into the signal, and then finish up with the sine wave for the rest of the signal.
Evan Collier
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Generate n sine waves and add them together
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I'm new to Labview and I want to generate n number of sine waves and add them together to form one signal that can be out put through a DAQ card. Each successive wave frequency will be the multiple of a base wave all will be the same amplitude.
This to me suggested a For loop with a sig generator and a passback in it but when I tried this it threw an error because the dt were different.
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ThanksShow us what you did.
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Simultaneous updation of sine wave using 2 PXI-6711 cards using RTSI Trigger
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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 -
I have a 50Hz sine wave and a pulse signal on a same graph. The phase difference between two is between 0-90 degrees.
Now I need to calculate the time difference between (when the sine wave crosses zero volts) and (when the pulse rises). The frequency will stay approximately same for both signals.
The application is for a three phase generator. In simple words, when the time difference between the zero-crossing of sine wave and the pulse rises increases, that means that the load on the generator has increases.
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I have attached a jpg (a graph that i just made with excel to explain). The time 't' is what I am trying to measure
Cheers
Awais
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.
But I did use the previous code posted and made some modifications to it and it seems to work perfectly. Now the next thing is to be able to get just that one value that tells you the first time difference.
Here is what I get using that code.
As you can see from the t Values. I only need the one that is highlighted. If there is a way to filter out the rest it would be great.
I was thinking of a while loop and as soon as the value is higher than 3E-5 it would store the number and stop the loop, but I'm not too familiar with arrays in labview.
Here is the the code modified.
As you can see, it wasn't that big of a modification and it still is your code.
I will keep trying.
Thanks for the help
Attachments:
FinalShockSpeed.vi 55 KB -
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I think you are on to something here, and I originally advised the admin to do this. The problem he ran into is that it setup the printer names in the TS as "printer on usersworkstation"
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USE LPT2 \\computer\printer password /USER:domain\user /PERSISTENT:YES and then tell the driver to print to LPT2 – James
Newton Mar
17 at 16:21
@JamesNewton That's actually the exact method we used. The way around the "network printer" part is to install it as local printer and map it to a TCP/IP port that way. – Nathan
C Mar
17 at 16:28
You mean in the case where the printers are TCP/IP connected and not local USB / LPT to the users workstation? That makes sense. Wonder if this will work for USB connected printers... – James
NewtonMar
17 at 16:35
@JamesNewton You'd share the local printer on the client's PC then on the server connect via TCP/IP to it. You'd need static addresses or use DNS names if DHCP, though. – Nathan
C Mar
17 at 16:51
Ah. Yes. I see. Looks like the LPT thing should work even with a USB connected printer:superuser.com/questions/182655/… – James
Newton Mar
17 at 17:09 -
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Message was edited by: Imol -
How to change the phase by 90 deg of a sine wave
Hi
Does any one know how to change the phase of a sine wave by 90 degrees.
MalHi Malkoba,
Thank you for your post.
Having looked at your VI I can say that you have created the correct inputs to the 'Sine Waveform.vi'.
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Regards,
Field Sales Engineer | National Instruments | UK & Ireland
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What problems did you have with extract single tone. Can you show some data where the results from it are not good?
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