An arbitrary waveform generator using the DSP Module

[GibbGodD]

Hi Guys,

Just got my hands on LabView and the DSP Module, and having a bit of fun atm. Great products. I'm currently using the TI DSK6416, and was wondering if there was a labview model/example of arbitrary waveform generation using this...? Perhaps using a DDS method or something similar?

Thanks in advance...

GibbGodD 

[Ben_S]

GibbGodD,

Hello!

There are quite a few Waveform Generation VIs within Labview, including the Simulate Arbitrary Signal Express VI and the Arbitrary Wave VI. Unfourtuantly, these are not available within the DSP Module. There is a special group of Embedded Signal Generation VIs for the DSP Module, of which one is the Simulate Signal. Take a look at these VIs as perhaps you could use them to build the waveform you are looking for.

To answer your question, I wasn't able to locate a specific example that matched what you were looking for, but if you to Help >> Find Examples >> Toolkits and Modules >> DSP from within LabVIEW you should be able to find some great DSP examples. Particular, the example project "Variety of Signal Types.lvproj" shows the different types of signals the DSP target can generate.

The majority of Arbitrary Waveform Generation information that I was able to find is all related to our Function Generators but not for the devices supported for the DSP Module.

Best of Luck!

[GibbGodD]

Hi Ben,

Thanks for the help, I appreciat your digging around on my behalf! Will give your suggestions a bash, and ill make sure to bother you should I run into any problems 🙂 Just one last thing, you mentioned that there are quite a few AWG VI's within labview but within other modules - which other modules? And do none of them make use of a DSP?

Thanks in advance once more...

GibbGodD 

[Ben_S]

GibbGodD,

The AWG VI's I mentioned are not part of any other modules, they simply come with the Base Package of LabVIEW (The express VI comes with the Full Package). To answer your second question, No, when you target a DSP board a subset of the Normal LabVIEW functions becomes available, and unfortunately these are not included.

[GibbGodD]

Hi Ben,

I am working with a DSK6416 and im trying to build a simple function generator as well as an arbitrary waveform generator. I thought a smart way of doing this would be to develop several little VI's (1 for sine wave, 1 for square wave, etc.) - then build these as .exe files and call them from a simple user interface built in VB.Net or something similar. However, after several attempts, it seems these executable cant be build - if I try right click on build specs under My Computer, and then goto the Source Files section, as expected the are no available VI's as they exist under the DSK6416 section.

Is there any way around this or any better way to do what I'm trying to? I want a VB GUI as for the AWG section I want the user to enter the desired waveform in equation form...

Any help is much appreciated!

Thanks. 

[Ben_S]

GibbGodD,

Check out this document on Using the LabVIEW Project with LabVIEW DSP Module, specifically the section on Creating a Build Specification to Flash a DSP Board. I think this is what you are looking for.

[GibbGodD]

Hi Ben,

Once more, thanks for the speedy response and assistance. Just a few questions based on your advice,

1] How many VI's can I load on to the flash memory of the DSK board? I know I could work this out by checking the avg size of a VI and the total available flash on the DSK, but I was just wondering if you could load more than one really...

2] So if I am able to load more than 1 VI, how to call these from the flash memory of the DSK through VB.Net for arguments sake? And would the VI's run as they would in LabView with Front Panel user interface and control?

3] Am I going about this the right way? LOL!

Thanks again for all your help mate.

[Ben_S]

GibbGodD,

Hello! 

You can load more than one VI to the DSK board, and how many completely depends upon their file size. That being said you can only have one of those files be your main VI that runs when your device is powered on. I would suggest having a Main VI that calls sub-vi's for each waveform you wish to make.

Now, as far as calling those things from VB.net, you can use Active X to interact with the front panel of your main VI. However, I know this works for LabVIEW normally, but I'm not sure if it'll work that way with the DSP Module. Here are some links that show how to do ActiveX from VB.NET to LabVIEW.

• Calling a LabVIEW VI from Visual Basic through ActiveX

[GibbGodD]

Hi Ben,

I have been trying to access my DSP based VI's through ActiveX, but to no avail. It basically does not recognize the elemental nodes (inputs/outputs) when run through ActiveX. Is there anyone you know could verify whether a method exists for doing this successfully? I've almost hit a stone wall trying to build my arbitrary waveform generator through LabView DSP module 😕

Thanks for all the help,

GibbGodD 

[GibbGodD]

Hi Ben,

Just one more quick question!

I have written a quick VB program that allows a user to enter a waveform, say: f(x) = 2sinx + 3cos3x + 5. The program then samples this and generates a table of values. These values are then converted to hex. Now, is there a way that I can input these points (in the form of a text file) in LabView to generate and output the resultant waveform?

Thanks again!