Write to measurement file every each minute?

[rockarmatte]

Hi everyone!

I have some problems with the function "Write to measurement file" and I hope that someone can help me!

I'm currently using a NI usb interface to measure the voltage and then calculate the frequency in Labview 8.2. I want to save the measured values in a file and open it in Excel. Therefore I use the "write to measurement file" but the timestep is so short and so I get plenty of measurepoints. I want to take samples like every minute or every 30 second. Is this possible?

Thanks for your help!

[John_P1]

Hi rockarmatte,

Here* is a link to some code I posted a while back that should be a good starting point for doing this.  There's nothing too fancy about it--it just uses the Elapsed Time function in LabVIEW to control when data is written to the file.  Out of habit I always use the lower level DAQmx functions but you should be able to stick with the Assistant if you prefer.

I hope this helps!

Best Regards,

John

*EDIT:  It looks like the actual code is not there but just the screenshot.  Hopefully this should be enough to tell what is going on but if you have any questions don't hesitate to ask.

Message Edited by John P on 11-16-2009 03:19 PM

[rockarmatte]

Thanks for your answer. I'm not sure that I have got it right. Should I connect the "multiply function" to the "time to target" ? And do I need to connect a wire to the "elapsed time" really?

I attach my Vi-file where I have added the new connection but it still will not work!

regards

Mattias

[John_P1]

Hi Mattias,

The "time to target" is just going to be the amount of time (in seconds) that you want to wait between each log.  The Multiply (x60) is there to allow the user to input minutes instead of seconds.  The boolean output of the Elapsed Time function ("Time Has Elapsed") is going to go high every time the time to target is counted to.  Since auto-reset is enabled, the timer will restart upon finishing.

-John

[kmarcella]

Hi,

I know this thread is really old but I am having the same problem. However I am using the Report Generation, not an express VI and am wondering what exactly I should put in the case structure so that this works the same?

And help is appreciated!

[Dennis_Knutson]

Duplicate - http://forums.ni.com/t5/LabVIEW/report-generation-write-to-file-at-interval/m-p/3117153

Don't post the same question multiple times.