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Writing multiple waveforms to a csv file

I am continuously collecting data from a current, voltage and temperature module and I would like to plot the three DAQmx Read (VI) output waveforms in a single csv file.  I will be taking samples at the same rate (1k Hz) for each virtual channel so I assume the time data for each respective virtual channel will be the same?  When I wire the three waveforms to a write to file or write to spreadsheet file I am receiving errors stating that there can only be one source.  How can I write these three waveforms to a single csv file?  An example containing a VI that writes three arbitrary waveforms to a single csv file would help me out immensely.  

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Message 1 of 9

From your description, I am assuming that your waveforms will have the same time constant. If this is true, the attached example should do what you want. This will take 3 waveforms, create a series of time values and save them all as a single csv file. Hope this helps!

Message 2 of 9
You could simply use the build array function and pass the array to Export Waveforms to Spreadsheet File.
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I tried doing that but when I wired all three waveforms to the single input of the build array function I received an error saying there can only be one source?  Could you post a simple vi showing how to wire up three random waveforms to the build array function to a write to spreadsheet file vi?  Thats really all I need to get my VI running.  Thanks

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Message 4 of 9
You just drag it down to create three inputs. Have you taken the LabVIEW basics tutorial?
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Message 5 of 9

Hello mbrupb,


Here is a VI that can show you how you can save 3 signals into a .csv file using the write to spreadsheet VI. In this example 3 waveforms are being generated and then written to the file.


I hope this help you with your project.


Best Regards

Field Applications Engineer
NI Colombia
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Message 6 of 9

Hi, im also facing this problem, i have a signal that is a special waveform, am i able to save the data as a csv file so that i can analyse it? i am unable to open the solution u gave and would love to give it a try in my project. (i am using Labview 2010)


here is the image URL: 

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Message 7 of 9

I converted the file to 8.0 for you.  2010 can open that.


How are you obtaining the waveform?  I see a scope screen capture, but you need the actual waveform data in order to save it to a csv.  Also, the scope may be able to save the waveform to a csv for you (I had an older Tek scope that did).

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Message 8 of 9

thanks in advance for the conversion. the image is taken from a oscilloscope but for the actual project i would be using DAQ9219 or 9222 for voltage capturing. 

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Message 9 of 9