Preserve original dt when reading TDMS

[DanielPodo]

Hi all,

I have the following situation. We have two VI's; the first reads a 3 GB TDMS file and lets us extract chosen channels, which we then may decimate, reduce bit size, maybe some other conversions, etc. We then save these channels as a separate TDMS file (naturally, smaller size).

The second is an analysis VI, which lets us mess around with the waveforms inside the smaller TDMS file. However, when using the TDMS Read function, it seems that it converts all the dt information back to a default of 1. One plausible solution is to set a data type control that lets me choose the dt manually, before the actual read process. However, this might be a bit cumbersome when dealing with a TDMS file with a lot of channels (I would have to set the dt for every channel, rather a PITA if I have to do this for 20+ channels).

Is there any way to read the TDMS file and extract the waveforms while conserving the original dt data?

Thanks.

[ValkoA · Accepted solution]

Dear Daniel,

TDMS Read should return the appropriate dt as long as it was saved properly. Try to create a small-scale test with writing then reading a small measurement file. 

Kind regards:

Andrew Valko

NI Hungary

[DanielPodo]

Thanks Andrew,

That's what I initially assumed, but I thought that maybe there was a bug in the TDMS Read function. It seems that there was a point in the program that inserted a dt value before loading it, and I must have overlooked it.

Now it works without issue.