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"write to measurement file" specify column names

I'm using "Write to measurement file" VI to create a TDMS file from 2 and possiby more data sources. Currenty the columns are titled "Untitled", "Untitled1", etc. I would like to specify column names. Can anyone point me to an example or tell me how to do this?

 

Thanks,

Ron

Message 1 of 28
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OK, I'll answer my own question if I can...so far I found a VI called "Set DDT (Dynamic Data) Attribute". I think this will do what I need, but I have to work with it a little longer. My data sources first have to be turned into dynamic data using "convert to dynamic data", and this wires into the "SET DDT Attributes" VI. When I drop this VI it displays a dialogue box which allows me to choose my options, including signal names. These names will be displayed in the TDMS file which is created by the "Write to Measurement File" VI.

 

 

Message 2 of 28
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Hi,

 

I've done some project with TDMS a few times and you can wire the column names (channel names) to the VI.  See attachement

Kind regards,

- Bjorn -

Have fun using LabVIEW... and if you like my answer, please pay me back in Kudo's 😉
LabVIEW 5.1 - LabVIEW 2012
Message 3 of 28
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I'm using the "Write to Measurement File" VI which accepts dynamic data which could have multiple elements. This VI does not have input for naming columns directly, rather it is required that the incoming dynamic data has names specified. This can be doen using another VI called "Set Dynamic Data Attrbutes" or "Set DDT Attributes". But each channel seems to need its own "Set DDT Attribues" VI, which can end up using lots of space if you have multiple channels.

I may not be doing this the most efficient way, but its working for now.

 

Write to Measurement File.png

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Message 4 of 28
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Hi!

 

Even I am having the same problem as yours! I also would like to change the names of the X columns! Could you please help me locate ''Set DDT'' in LabVIEW 8.5!

Where can I find it? and is it possible to delete the extra information before the measurement readings? PLz help me!

 

Thanks in advance!

 

Vinay

 

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Message 5 of 28
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Vinay,

 

It should be under the express VI's in the "signal manipulation" folder. In some versions, its just called "Set Attributes".

 

 

Daniel

Applications Engineer
National Instruments
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Message 6 of 28
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@Daniel-H wrote:

Vinay,

 

It should be under the express VI's in the "signal manipulation" folder. In some versions, its just called "Set Attributes".

 

 

Daniel


No. The function does not exist in 8.5. It was added with either 2009 or 2010. Prior to this, you would convert to a waveform datatype and then use the Set Waveform Attribute. The attribute is "NI_ChannelName"

 

 

Message 7 of 28
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Dear Sir,

              Thanks for the immediate reply! But I am using LabVIEW 8.5 version and I could not find it in signal manipulation! I have a two sets of 1 D array data which  needs to be saved in an excel sheet! One array is Power in mW and the other array is Current in mA. So how do I name the columns with these names? And also I dont want the number of samples, channels or X_value to be displayed in the saved measurement file! How do I delete them or avoid them?

 

Please try to help me as soon as possible as I have almost finished my project and waiting for only this thing to take the right form!

 

Thanks!

Vinay

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Message 8 of 28
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I just told you that the express VI does not exist in 8.5 and I told you what function to use.

If you don't want the header, don't use the function.
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Message 9 of 28
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Dennis is right. There are no express VI's in 8.5. That was my mistake. Using the functions he recommended in his post are, what I believe, the best way to handle this.

 

Daniel

Applications Engineer
National Instruments
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Message 10 of 28
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