arbitrary waveform from file

[adnaan07]

Hi,

I would like to input a text file with the (x,y) value pairs that represent the signal. I then want to parse the file and feed the value programatically into a VI that can create the waveform. I think I can figure out the parsing part, but once I have the value pairs how do I generate a signal from that. I tried using the "Simulate Arbitrary Signal" express VI but it doesn't have an input for values. You have to manulally input the values into the express vi. Is there a way of automatically generating a waveform from a value pair?

Thanks,

Adnaan

[GovBob]

Do you have any hardware to generate this waveform? If you look under the example finder for "Graphs" you will find an example for "Waveform Graph". (Assuming you have LV 8.5). This should give you some ideas. Also look at the build waveform function under programming>>waveform. Put one of these on a block diagram and turn on the context help (Ctrl+H).

Hope this helps

[MikeS81]

Hi Adnaan,

you can use the "build waveform" function. If your values have different time values between two points you have to interpolate it, so that you have one dt between all your values. If this is done you can set your start time, your dt and an array of your values.

Mike

[adnaan07]

Hi,

I want to produce the arbitrary waveform on the DAC0 channel of the ELVIS. So a user inputs a file and I want to take the (x,y) pairs and output them to the ELVIS using the 'Arbitrary Waveform Generator' express VI. Before I do that however I need someway of converting the (x,y) pairs into a waveform that I can then feed into the 'Arbitrary Waveform Generator' express vi for the ELVIS. Hope that makes the question clearer,

Thanks,

Adnddn

[TMC-NI]

Hi adnaan,

Probably the easiest way to do this would be to convert your text file to an .lvm file initially, and just using "Load Data" from within Simulate Arbitrary Signal to take in those values.  That way you wouldn't really need to worry about parsing your values, and even better is if your file was already an lvm file, you would directly just load the data in to that express VI.

If you'd rather not do that, then you can use the build waveform.vi, and we have an example on how to do this in the Create Waveform example.vi in the example finder.

[0802352 5955]

hi...

But how is this .lvm file created....???

Any kind of help is appreciated

Regards sush

[smercurio_fc]

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@0802352 5955 wrote:

hi...

But how is this .lvm file created....???

Any kind of help is appreciated

Regards sush

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Please do NOT create multiple posts with your question. That is very irritating. Your original post:  http://forums.ni.com/t5/LabVIEW/to-create-lvm-file/td-p/2019698