error reading TDMS file with inconsistend dt

[lopez]

Hello all,

I would like to ask your help to understand how to read a TDMS file which I am opening and closing based on a user input.  As a result the data in the TDMS file does not have a consistent time step, which may be causing my problem, but I really don't know.  I keep getting the error 2501, that I have an invalid reference. 

Or, if I continue and bypass the error, the extract portion VI gives me an error stating that I need to define an integer multiple of dt.

I am not sure how to solve the first point as I have the reference wired directly to the read TDMS vi.

I have attached a screen shot of the error and the portion of the VI with the offending error (it is the code connected to the read TDMS read vi).

My goad is to extract a portion of the data to do calculations on and display a result to the user.

thanks for any comments.

[TCPlomp]

I think you open multiple times the same TDMS file, you should open it before the while loop. And I don't see a close tdms function...
Also check for errors on the open TDMS function.


Ton

Message Edited by TonP on 02-14-2007 07:45 AM

[lopez]

Ton P,

thanks for the tips. my computer crashed and I could not do anyting the last couple of days, but I investigate more and post again if still having trouble.

[pshadlyn]

Did you ever end up solving this?  I am now encountering the same problem.

[Kristen_K.]

Hi lopez and pshadlyn!

I would recommend taking a look at the "TDMS-Write data (time domain).vi" example found in the NI Example Finder (Help>>Find Examples).  

Kristen H.

[pshadlyn]

Thanks Kristen, I've managed to get it working now.  The VI I had written was structured very similar, but I didn't have all the errors in/out connected from each TDMS block.  I've connected them and now it's working fine.  I'm a little confused by this, why would it make a difference?  I'm new to TDMS reading/writing and I'm just trying to figure it out.  I've attached a picture of my VI.  It's a small stand-alone VI.

Thanks.

Phil.

[Kristen_K.]

Hi Phil!

I'm glad to hear it is working now.  It's hard to tell why wiring the error wire through fixed your error, without looking through your code.  However, the error wire will force the execution order becuase VIs will wait for all of their inputs before executing.  Best of luck with your application!

Kristen H.