Data from Elapsed Time VI format

[anthony797]

I am using Elapsed Time VI to create a time line when I collect my measurement data as followed picture.

Two question about this vi:

1, what I set for the output is double precision, but when I look into the data file I saved(TDMS or text file), it only shows like 6 digit after decimal. Is it because it just print the number out for better reading, but it still is double precision?

2, I would like to measure the data for a long time, like a few weeks. What is the maximum number it can count and is it still precise enough to distinguish the adjacent huge number? 

[RavensFan]

You only showed a very small section of your code.  I'm guessing you are using an Express VI to write to the file.

The problem with express VI's is that while they make throwing together working code easy, and allow a bit of customization, they can't anticipate everything you'll do.

Many LabVIEW functions assume a %.6f format string which means save a value in text as having 6 decimal places.

Without seeing how you are writing a file, and that means actually attach your VI and not a picture, we can't help much more.

[aeastet]

I would use get time in seconds. See below:

Doing it this way you should not have any limit.

[anthony797]

Hi  RavensFan,

Thanks a lot. 

Because my code looks complicated, I will clean it up and upload it soon.

Yes, I use the Write To Measurement File VI to save it with my measurement data stream.

I think you are right that it assumes a %.6f format string. Is there a way to really save DBL and I don't have a limit to count time for a few weeks?

[anthony797]

Hi Tim,

Thanks! However, "get time in seconds" returns a time stamps. What I want is the time counting from zero to weeks.

[aeastet]

then take the initial time and subtract it from the time now.