Waveforms TDMS output files not UTF-8

[bungernaut]

I have found an issue in trying to read TDMS files into python using nptdms module. The module author figured out that Waveforms is breaking the TDMS standard in the phase property unit. You can see the issue here:

https://github.com/adamreeve/npTDMS/issues/294

I guess this changed recently since I have files where this worked and then it started to be an issue. 

Right now the problem exists for me in 3.18.1 64-bit Qt5.12.9 Win 10.

bad_utf8.tdms good_file.tdms

[attila]

Hi @bungernaut

It will be fixed in the next version 3.19.12 this week utf8.tdms

Thank you for the observation.

[attila]

Hi @bungernaut

 

[STMAN]

Hello.

I'm using the Beta 3.21.19 of WaveForms. TDMS file format issues still there with LabVIEW.

Help needed here.

I'm having some problems with LabVIEW when trying to work with TDMS files generated by WaveForms : While "known to be okay" TDMS files work perfectly with LabVIEW, the ones created with WaveForms Scope "Rec" (Recording function) always fail when used with simple LabVIEW demo code (To simply read a TDMS file and perform an FFT on it : https://forums.ni.com/t5/Example-Code/Read-a-TDMS-File-Take-FFT-and-Write-to-TDMS-File/ta-p/3527396 )

 

When processing the WaveForms generated TDMS file to perform a Power FFT on it, an error pops up (But the "Measured data from TDMS file" bloc seems to be able to read the file correctly) :

 

[attila]

Hi @STMAN

The next software version will add 'delta t' property to the TDMS exports.

 

[STMAN]

Thank you very much for patching this small bug rapidly, because I bought the Digilent Analog Explorer 3 mainly because it was possible to use it off-line or on-line with LabVIEW, and my first steps with LabVIEW were failing because the data format not exactly fitting NI TDMS format.

 

I take advantage of this quality interaction with you to push a request :

I've read, for my personal culture, about the TDMS file data format and I acknowledge its inner complexity which is real, but Digilent is a leading low cost and high quality instruments & dev boards manufacturer, and such things, importing/exporting data to due format, are expected to work perfectly.

Due to the complexity of the TDMS format, and the wide variety of usages and applications with such files, that it would be very interesting and handy for end users to have Digilent creating an optional dialog to fine tune several meta data fields (Like changing the names of some channels, selecting some possible formats for the corresponding raw data, fine tuning things like the kind of acquisition done {decimate, full range, average, min max}, and many other settings caracterizing an acquisition of raw data, selecting if we export the signal, signal+noise, or noise, as different TDMS channels, or not) before generating an exported file, so that advanced users like me seeking fine signal analysis using external third party tools like LabVIEW or MathLab could eventually manually change a few things in the metadata or the raw data and its formats so that it works fine or better for very specific applications with LabVIEW or else.

It would also be interesting to have a clear detailed summary of any exported final file format used (TDMS, Binary, text) so that the user can easily use the exported data into custom parser programs of his own (The detailed format of the file header, will all fields and their value, plus the raw-data sections offsets etc...). There is currently a short summary printed on the dialog at generating some exports, but it is not detailed enough to allow the user to know exactly the format and size of the file header, and the offsets and format of its raw data content.

Proposing a kind of more complex dialog for the export in TDMS format, (And for binary format too, indeed), to fine tune the meta-data (and the raw data and its format) of a TDMS file export that would be 'auto-filled' but editable by the user in case of necessity, would be a good thing to include into WaveForms.

I'm looking forward for your reaction to this modification of the Export Dialog of WaveForms.

Kind regards,

Frédéric.
 

Edited December 17, 2023 by STMAN