ELVIS II+ oscilloscope

[JoseRamos]

Hi all:

I just got an ELVIS II+ unit and am starting to build some basic circuits.

Does anybody know if the oscilloscope has a math function? I need to

subtract two signals. Any help doing this will be appreciated. Thanks,

Jose Ramos

[Wan-L]

That depends what oscilloscope you are using. In LabVIEW, you can subtract two "signals" but it depends how the data is represented. Are you looking to subtract arrays or waveforms?

[JoseRamos]

Hi Wan:

I'm trying to subtract two waveforms like you would do on a normal oscilloscope using the MATH

function of the oscilloscope (-) . It appears the SCOPE built into ELVIS II+ is a very simple one,

compared to a real oscilloscope. Are there any math functions? Are there any other scope VI's that 

resemble a real oscilloscope? and if so, can I use it with NI ELVIS II+? Thanks for your help.

Jose 

[Wan-L · Accepted solution]

You can just add them using the regular "add" primitive VI. 

[charlesy]

Hello Jose,

Just to clarify, yes -- the ELVISmx Oscilloscope is intended as a easy-to-use getting started experience. If you want to do something more sophisticated, you can do that in LabVIEW. If you would like to tweak the ELVISmx oscilloscope instrument, we include the source code here: 

C:\Users\Public\Documents\National Instruments\NI ELVISmx Source Code

It's very complicated under the hood because it is used for Express VIs and Multisim integration, but you could inject a math function in the "Acquire" or "Update Display" cases.

If you don't want all of the scope-like functions and just need to measure a signal, you can also write a simple program using a DAQ Assistant Express VI to acquire with whatever configurations you need and then do the math functions before graphing.

Finally, if you prefer less programming, you can use SignalExpress to drop an Acquire Signals step and then an Arithmetic step under the Processing category.

Hope this helps,

Charles Y.

National Instruments

[JoseRamos]

Charles:

Thanks for your reply. That gives me a starting point.

Jose