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How to change 'untitled' in 'write to measurement file' block

That would be a much cleaner way to do it, but the reason I could not even try it is for the following reasons:

 

1. How to output 'waveform' from DAQmx Read  (thanks Mike!)

2. Is that an array of channel names going into the for loop?  Is there some way to get this from the MAX task I'm using?

3. If so, what is NI_ChannelName?  

4. What the heck is that yellow box?

 

So you see, it's not so far-fetched that I didn't 'even' try it; These things are not obvious to all of us

 

And yes, I did do a search of the forum for this 'problem', that's how I found this topic!  Smiley Surprised

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Message 11 of 19
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You're using 2009 aren't you? That png is a snippet and you just have to drag it to a block diagram. You will have an actual block diagram that you can run and use the help with.

 

NI_ChannelName is the specific attribute the express VI uses. Yes, it's an array of names, and right click on the DAQmx Read or click on the polymorphic selector below to change data types.

Message 12 of 19
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Try this VI I made. It takes in a Double signal and a string, names your signal, and outputs it as a Dynamic Data.

I used this with the Write to Measurement File without any issues!!!

 

Name DBL Signal VI.png

 

 

To name a Dynamic Data Signal, use the Set Dynamic Data Attributes VI found in Express > Signal Manipulation

 

Hope this helps,

Cheers

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Message 13 of 19
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So why would someone who is using dynamic data (unfortunate person) use your VI instead of the express function? I'm not a big fan of express functions but it does the exact same thing as yours plus the ability to change other attributes.

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Message 14 of 19
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Right under my picture it says "To name a Dynamic Data Signal, use the Set Dynamic Data Attributes VI found in Express > Signal Manipulation"

 

I tried using the Set Dynamic Data Attributes VI for a DBL signal but it didn't work. I also tried using my custom VI in a for loop so you wouldn't need multiple instances of it, but I counldn't get it to work. Your more than welcome to try and help with this issue.

 

Cheers 

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Message 15 of 19
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The express vi seems to work just fine for scalars. Perhaps you should try it again and if it does not work, post your code.
Message 16 of 19
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You are correct. The Set Dynamic Data Attributes VI found in Express > Signal Manipulation worked in the program also. I don't know what I did before to make it not work. Probably when I attempted to feed the VI multiple signals, it started to choke because I did it incorrectly.

 

This was a good learning experience though. Now I know how to make a Sub VI!

 

Thanks for the tip

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Message 17 of 19
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If i use Signal manipulation-Set Attributes then signal name is changed but other problem is timestamp, only first row time is OK other is :

 

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Message 18 of 19
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Hi mortenx,

 

Can you post your code? We might need to see how you have the VI configured.

 

If not, you might find useful information on these links:

http://zone.ni.com/reference/en-XX/help/371361H-01/lvexpress/signal_manip_express_vis/

http://zone.ni.com/reference/en-XX/help/371361H-01/lvexpress/set_ddt_attributes/

 

I hope these might help you.

 

Regards.

 

Luis C.

National Instruments 

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Message 19 of 19
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