Waveform averaging

[jtd30]

Dennis,

Could you post a copy of the average.vi in version 8.2?  I cannot open the file you posted previously.  Thanks.

[Dennis_Knutson]

Sure.

[jtd30]

Unfortunately that did not solve my problem.  The plot of the waveform still varies substantially through each iteration.  Also, as the vi runs, there is an error in the time step or the time stamp between the generated toneburst and the averaged plots.  The dt between the two continues to grow with each loop.  It appears that I have created more than one problem.

[Anna_K.]

Hello Jtd30,

Can you verify that you are getting the correct data in? Does the error occur in the averaging calculation and everything is as expected up to this point?

Regards,

Anna K.

[jtd30]

Anna,

Thanks for the reply.  The generated waveform is correct.  However, The data that I unbundle by name after the index array of the 1-D array of clusters that comes from the niScope Multi Fetch Cluster is not correct.  The graph appears to have the correct amplitude, frequency, etc. but the values do not correlate.  I ran one iteration of the loop so there was no averaging involved and the two sets of data should have been the same however, the probe values where not the same.  I'm assuming that my programming and the use of the elements are correct.  I copied them from one of them examples from the NiFGen group.  Your help is greatly appreciated.  Thanks.

Jeff

[jtd30]

Anna,

Have you had an opportunity to review my vi?  I still cannot seem to locate the source of my errors.  Thanks.

Jeff

[Anna_K.]

Hello Jeff,

I will have the team that supports the NI Scope take a look at it.

Regards,

Anna K.

[Aaron_W.]

Jeff,

Looking through your code there is nothing that glares at me right away.  If I understand correctly from skimming through the past couple of pages it seems as though you are to average your waveform that you are taking in to get rid of noise that you are seeing in the system, is this correct? It does appear as though you have the scope section of the code correct, it just has to do with how you are averaging the values within the software. I also understand that when you look at the info from channel 0 and channel 1 this data is correct? 

Sorry for not being able to give you an answer at this time, just trying to get caught up on the issue. THanks. 

[jtd30]

Aaron,

Actually the only thing I am trying to do now is generate a toneburst from the function generator and receive it with the scope.  I have the function generator wired directly into the scope at channel 0 (channel 1 is not used at this time).  So the generated toneburst should pass directly from the function generator to the scope and the data should match.  When I place a probe on the wires in the block diagram the values from the generated toneburst do not match the values that come out of the ni Multi Fetch in the waveform.  So the data itself is not correct.  The averaging my be correct once the data collection error is resolved.  Thanks.

Jeff

[Aaron_W.]

Jeff,

My best recommendation is to look through some of our example files and either compare those programs to your own or start from one of our example programs and then add your averaging function to the example. One example that I think would be a good starting place is the niScope EX Configured  Acquisition. This can be found either through the example finder or in the following directory: Program Files\National Instruments\LabVIEW 8.6\examples\instr\niScope. These scope examples are guaranteed to work and you could try adding the necessary function to the example.