Create Multi-plot waveform from tdms file

[THurst]

OK I am a newbie. PLease be patient with me. I have taken no classes yet but plan to. I have tried to create a multiplot waveform from a 19 channel tdms file which was captured in SignalExpress 2.0. What I would like is to read the file and create something similiar to what SignalExpress calls Project documention. In other words I would like to output a waveform for each channel to a report. I have tried the help for TDMS read and I can't get more then one plot to show up or all the samples are not shown.

[Herbert Engels]

Have you tried the TDMS File Viewer? It will show you what all is in the file, which, for SignalExpress logs, is a little more complex than you might expect. By default, the viewer only shows the first 100000 or so values of a channel, so if you have huge files, it won't use all the memory you don't have. You can configure it to show more if you need that.

SignalExpress stores a group for each signal, where up to 6 reduced traces for each signal are saved in addition to the original signal. You need to use the group names in combination with the names for the unreduced data signals and wire these to TDMS Read. Once you have the names, you can go with help/examples to figure out how exactly TDMS Read can be used.

Hope that helps,
Herbert

[THurst]

Yes I have tried to use TDMS viewer but it erros out, must be the complexity of the file. I have attached a file I am trying to read and it seems to complex for me.

[Herbert Engels]

Works just fine for me. See attached screenshot.

The viewer shows 19 groups with names like:
7/31/2007 10:03:05 AM - 3253008-8 SN 107 - A0 Yaw Servo Current
and 7 channels each, 1 original channel named "Trace_FullSet" and 6 reduced channels.

Try wiring the above group name and "Trace_FullSet" to TDMS Read.

Herbert

[THurst]

I know the data file is good I just can't read it. Everytime I try to use TDMS Read the program exits with a problem (See attached).

[THurst]

Thank you for all your help.
Here is the VI I have been trying to read with. It should be the TDMS file previously attached.

[Herbert Engels]

You are opening the file, reading from it and not closing it and you are doing this within a while loop that runs at full speed. That way, you keep opening new file connections and loading new data until your machine runs out of memory.

1) Remove the while loop and the "stop" button and run the VI. You'll see data.
2) If you have to read mutliple times (so you have to use a loop), open the file outside the loop, keep the TDMS Read in the loop, and close the file after the loop is done.

Herbert

Message Edited by Herbert Engels on 08-05-2007 02:35 PM

[THurst]

Deleted the While loop and added TDMS Close, still no plot. I am sure it must be something simple but I can't get it.

[Herbert Engels]

The crashes on your system make me think that something must be screwed up with your installation, and if we can't get around these crashes, we need to dig a little deeper in what all is on your machine. But first, let's see if we can get your system to load any data.

Try the attached VI. See if it produces the same image that I have attached.

If you don't see any data, please go to Program Files/National Instruments/Shared/TDMS, right-click TDMS.DLL, select "Properties" and look for the "File Version" on the "Version" tab of the dialog you will see. The file version will look something like this: 1, 0, 467, 976. Put it in a reply, along with the versions of LabVIEW, SignalExpress, DAQmx and other NI Software that you have installed. Note that software that is not directly involved in what we're trying to do here still can have installed something that creates a version mismatch, which would be the root cause of your problem. That doesn't happen a lot, but it can happen and we need to dig this up, so we can get your app running.

Herbert