problem with TDMS file and Origin

[MargheTB]

Hi, I've got a problem with the "write to measurement file" vi and the tdms files that it creates.

I'm acquiring data with an ADC card, these data are then stored in an array in which I have to add 1 row (to indicate wavelenghts) and 1 column (time).

when I try to open data with Origin 8 it seems that sometimes it doesn't recognize the time column and the wavelenghts row as composed by numbers, so that when I plot data the x axis has 1,2,3,.. instead of having for example 0, 5E-9,1E-8,... Is there a wrong import option? But it's really strange because sometimes it works fine and sometime not!

I'm sorry but I cannot post the entire Vi because it's really huge!

I'm working with Labview 2010.

Thank you!

Bye

[YongqingYe]

Hi MargheTB,

Origin is not NI's software although it can import TDMS files. I would recommend you firstly make sure whether the TDMS file is correct, you can use NI software products, like LabVIEW, DIAdem and so on to validate. You mentioned you have LabVIEW 2010, could you please open the TDMS file with LabVIEW TDMS File Viewer? Is the content what you want?

[MargheTB]

Thanks for your reply! The file is correct. I've tried to open it also with the TDMS file viewer, as you suggested, althought it was correct even with Origin (As you can see in the picture - data.jpg). But the problem is that when i try to plot them Origin doesn't recognize the x axis, for example the time line or the wavelenght line, and instead of the values of the first column of the picture i get only 1,2,3... (as you can see in the picture called Graph) and, as I said before, it doesn't happen every time with the wavelengths line, but very often with the time line (in my opinion it could be something connected to the format of the value, but at the moment I've no clue on how I can solve it!). So I was wondering if anyone else had this problem before, if there is any import/export option that must be changed, etc... I would probably have to work with Origin, and I don't wanna have this problem!

Thank you!

Bye!

[YongqingYe]

Seems something wrong when Origin plotting the data, it sounds like applications would take the first channel as the x axis, but in your attached picture, it was obviously not. It's just my guess, maybe there's some place you can configure in Origin to load which channel as the x axis.

[MargheTB]

Thanks again!

So, it seems that there are some "hidden columns". when I click on one of column I can see one button called "Show x column" which then shows a new column called Time and it is this one that it is displayed when I plot data (because when I delete it I can finally plot the right time axis). and every column (so every channel) has its hidden x-axis. is there a way to get rid of them? Does the write to measurement file vi always create them for each channel??

Thanks!

Bye!

[YongqingYe]

If the time interleave is all different, then Write Measurement Express VI has to create a channel of timestamp for each channel, if in this case, I'm afraid there's no other way to get rid of it.

[MargheTB]

it seems that all the hidden columns are the same, also because the sampling it's the same for every acquisition. so do you think that I can do anything? Would it be the same if I'll use other VI, such as the storage vi??

thanks!

bye!

[Topper_Harley]

Do you realize that you add an empty time column to the x-axis in the save options?

[MargheTB]

mmm... I've tried different combinations and the one showed in the picture was just the last one (I'm sorry, I should have told that before), and I've also tried "one column only" but I've got the same problem (each channel has its hidden column), and however the time column is hidden, but not empty.

But still I was wondering if with other save function (for example "Storage Vi") I could have the same problem or how I can avoid the creation of these columns, because I'm dealing with a huge amount of data and I don't need to have more columns!

Thanks!

Bye!

[Topper_Harley]

Have you tried using the LabVIEW low level TDMS API functions? The give you full control of what is written to your file.