Tailored Waveform Voltage

[Sedulous12]

Dear Friends,

I am new to LabVIEW and just installed it, I am learning to create a tailored waveform voltage as attached, and send it either to a function generator or an oscilloscope; but I got stuck with putting all the parameters of the equation and successfully run it.

I am attempting to replicate a similar tailored waveform voltage attached using the attached equation, at a fundamental frequency of 13.56MHz. Please, how can I generate this tailored waveform voltage using LabVIEW? Thank you. 

Description of the parameters in the equation

 

[Henrik_Volkers · Accepted solution]

I can't open you vi due to older LV revision ....

For the DAC or AWG you need at least data for one (or more) periode that match the samplerate and output frequency. Depending on your hardware capabilities and how exact you need to create that frequency  there might be limits, unless you calulate the output values on the fly to feed a fixed frequency DAC at at least say 10 (better more) times the frequency you want to create (8 times is Shannon limit but with phase constrains for 4 times base frequency)

So what hardware are you using, and what output frequency constrains do you have?

As for the puse creation:

Here is something to play:

The cited publication .. lets say .. is not easy to decode  and the picture uses an uncommon (in my view) RMS value for  normalisation, tried equal RMS value with 1 order (sine) as reverence... added some more 😉

[Sedulous12]

Hi Henrik,

Thank you for your response. I am not sure if I fully understand what you meant by data for one (or more) periods that match the sample rate and output frequency. I plan to use a Tektronix AFG3052C Dual Channel Arbitrary/ Function generator with 1GS/s 50MHz, and also later use a Tektronics 6 series Mixed Signal Oscilloscope MSO64, 2.5GHz 25 GS/s.

I am not sure which of these devices will be suitable for the tailored waveform voltage.

Please, do you have any guide that can point me to how you created your tailored waveform voltage? That is what I am attempting to achieve. I am not sure I understand how you generated the sample and pulse pattern and normalized it on your front panel

Please find attached a screenshot of my attempts on Labview to create the waveform on the block diagram and front panel and the file again; I got stuck on inputting the equations into the for-loop, and I am unsure if I am navigating in the right direction.

Thank you 

Kind regards

Sedulous12

[Henrik_Volkers]

So you have your AWG with 1GSPS, that would result into 73.7463126844 sample at 13.56 MHz ..

So for one periode of your signal you can use 73 or 74 sample , resulting in different frequencies...

but you can use some math to see how many periodes of you signal will fit into your AWG memory and at how many periodes you find your best frequency match.

Some AWGs have some contrains for the memory use, not only size , some only read only multiplies of 2 or 4 sample.

If you want to use LabVIEW to control your Tek equipment, have a look for the LabVIEW driver  ..

best to connect the instruments to your system and try Help/find instrument driver in LabVIEW

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=6EC36E806C121C7AE04400144FB7D2...

RTFM of your equipment also help to understand how it works and how to do what you want with the stuff you can get 😄

[Sedulous12]

Thank you for the clarification and also sharing the instrument driver link with me. I would keep that in mind and hopefully be able to successfully generate the tailored waveform voltage and the tailored waveform voltage that will be suitable for the device. Thank you once again

[Henrik_Volkers]

here is another way to create the waveform:

in the formular cos() is used, LabVIEW provide a tone generation vi (with sin() , well cos(x) is sin(x+90°) 😉 )

So first the parameters for the added sines are calculated and the points are created depending on the samplerate and number of samples and as a continous stream ..  however it will be hard to stream 1GSPS 😉

[Henrik_Volkers]

Last hint: If you feed your 1 GSPS AWG with 4941 Samples of your 13.56 Mhz wfrm .. you pretty much hit it .. 67 (66.99996 ) periodes nearly fit into 4941 ns

(if your AWG allow an arbitary number of sample ... )

[Sedulous12]

Thank you so much 

[Sedulous12]

Hello all,

I tried loading the waveform generated from LabVIEW (after converting it into a wfm format) into an MSO64 Oscilloscope 2.5GHz, 25GS/s, but giving the error message: 'Invalid source for the arbitrary waveform.'

I also tried using the Arbexpress app to create the same waveform and tried loading it on the scope, but it gave the same error.

I have also attached the waveform generated for one harmonics of both the LabVIEW and Arbexpress using parameters below the maximum values of the scope; also attached are the maximum values for an arbitrary waveform in the scope and the error message inside a zip file.

please can anyone assist me on how to resolve this problem. Thank you.