Odd Behavior With TDMS Read and FFT Data

[Lukin]

I am creating a test system that acquires a bunch of data converts it to the frequency domain and saves it to a TDMS file with a bunch of meta data.  I just went to read the data and found some strange behavior with the TDMS read function.  When connecting the FFT cluster ( 1D array of magnitude, f0, and df.... This is the output of the FFT Spectrum (Mag-Phase) VI among others)  to the "data" input of the TDMS read I get a broken wire.  However the data ouput of the TDMS Read converts to the proper format.  If I create an indicator on the data output I can do so without a broken wire to the indicator.  If I then do an Undo to remove the indicator it disapears as expected but the wire on the data input is no longer broken. 

Steps to reproduce:

1. Place TDMS Read on blank diagram.
2. Take FFT constant and wire to data input of TDMS Read.  (I create a constant off the output of the FFT Spectrum (Mag-Phase) VI to get it)
3. Right click on data output of TDMS Read and create indicator (does the same thing with a constant).
4. CTRL-Z to undo.  
5. See the now unbroken wire.

This snipet should reproduce it by following the steps above.

I have seen this behavior in 2014 64bit and 2015 32bit.  Anyone have any thoughts about what is going on here.  I am sure I can find a way around it but it is kind of anoying

[ThibaultP]

Hi Lukin,

Maybe this link will help you in your research :

https://decibel.ni.com/content/docs/DOC-9613

I used it with LabVIEW 2015 32 bits and it worked well

[Lukin]

Hi ThibaultP,

Not sure how that example is of much help.  I am trying to read data that is already in the frequency domain from the TDMS.  Did you try the steps I listed exactly?  I have now seen it across multiple computers and in addition to multiple LabVIEW versions so it seems odd that it would be something wrong with my install.  

I have done a little more homework and it looks like TDMS Read help does not list this data type as an option. 

TDMS Read Function 

 

That being said I have no issues writing to it and Diadem seems to have no issues reading the data.  The f0 and df seems to be saved as properties so I can reconstruct the data type with issue but still seems confusing to have it create a broken arrow but still set the output correctly.  

Thanks,