Can you slow the scan rate of VI Logger scans per minute

[E.Carroll]

Can you set up a logging task with VI Logger to log 1 scan per minute? I'm using a DaqCard AI-16E-4 and SCXI 1120 Module.

[mikeporter]

What do you mean by VI Logger? The easiest way to do what you need is to create a while loop and put in it one of NI's "easy-IO" analog input VIs and a wait function set to 60,000 milliseconds. Depending upon the acquisition VI you use the result would read either one point, or a set of predefined points once a minute. (see attached code)

How much more complicated the application would get depends on such things as what exactly you want to do with the data, and how you want the user interface to react. For example do you need to save the data? If so, you'll need to add a file save function to the loop too. Also, the simple version I attached could take as long as 2 minutes to quit once you press the stop button--which probibly wouldn't be acceptable.


The point is that the basic functionality you asked for is very easy to do. The complicated part is defining all the other stuff that wraps around that simple functionality.

Mike...

[Annette Perez]

Hello,

The only parameter that can be changed while setting up a task in VI logger is the "scans per second", which corresponds to your DAQ board (1 to 100KS/s).

Since VI logger acquires continuously, the minimum number of scans that you can do per second is one; this is why you will have to at least log 60 values per minute into the file. Unfortunately, there is no way to change this parameter since it really depends on the hardware of the board, not the software.

If your application requires to log every minute, I would recommend to use LabVIEW (AI OnePoint.vi). With this software you will have more flexibility over the "writing times" and the results will be the same.

Hope this helps. Keep up with the great work!
Have a nice day!