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TDMS recording time

Hi Julianne,

 

DirectX is dll for video capture. I will upload those two with this post. I didn't see any timestamp issue with the highlight run. But the TDMS file's time is confusing, and I can't hightlight run for the TDMS recording.(I want to know how and which time stamp did TDMS record).

 

Thank you!
Ivy

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Message 11 of 17
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Hi Ivy, 

 

Express VI's can sometimes be confusing because you can't see what happens inside of them. Although this creates a bit more work for you, I would recommend writing the code for writing to a TDMS file yourself so you can see how the data is handled easier. A good place to start with this is the example finder. To get to the example finder when your vi is open, go to "Help" on the top menu bar, then go to "Find Examples..." I would recommend the following examples:

 

1)  Write TDMS File.vi

2) TDMS - Write data (triggered).vi 

 

The first example shows the basic requirements for building the program to write to a TDMS file. The second example might relate to your application a bit more. Let me know if this helps with tracking the timing of your data. Best of luck, 

Julianne K
Systems Engineer, Embedded Systems
Certified LabVIEW Architect, Certified LabVIEW Embedded Systems Developer
National Instruments
Message 12 of 17
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Thank you so much Julianne, I will read them through!

 

Have a nice weekend

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Message 13 of 17
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Hi Julianne,

 

I didn't find any example which can write current time(column 1 and column 4 in the excel file which I uploaded) into TDMS.

 

I open the express VI for writing TDMS file in the vi I uploaded and find timestamp in it. There is a file named"ex_subFileWrite.vi:3(clone)". I want to highlight run it, but it refused to be changed. Is there anyway I can play with it? BTW, I don't know where it is stored. There is no property for this VI.

 

Thank you!

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Message 14 of 17
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Hi Ivy, 

 

You will probably not be able to change the timestamp of the Write to Measurement File Express VI. Express VIs are wonderful for getting started with LabVIEW programming, but you will have greater control over certain aspects of your code of you use the lower level TDMS VIs. Please look at this Community Example on Timestamping Queued Data and Storing in TDMS Files. As you can see, you need to convert the timestamp data to a format the TDMS file write can take in. From there, you should be able to get the timestamp data you want. Hope this helps. 

 

~kgarrett

 

 

 

 

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Message 15 of 17
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thank you for your reply, but the link does NOT work. Could you please update it.

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Message 16 of 17
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You should be able to get it here.  If that does not work, go to the top level NI.com and type "timestamping queued data tdms" into the search box and it will give you a working link to the document.

This account is no longer active. Contact ShadesOfGray for current posts and information.
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