Some question on labview

Question

Hi all,
There is something I dont understand. I'm using LV 6i and NI6070E daq card. I'm using the AI and DIO to read my program. I used DIO to write my LEDs to alternating turn on and off. I realise, if I maximize my front panel to read, it slow down the freq of my LEDs, if I minimize the front panel, I'll get back my original freq. Can anyone explain to me why is that so. How can I resolve this pro?

Answer 1

Hello,
All AEsulzer was saying is that if you have any hardware dependent code which returns data to you, you should instead replace those functions with something very simple such as just the uniform(0,1) random number generating function.  Otherwise, since we don't have your precise hardware setup, we will not be able to execute your code and reproduce the problem.  The attached screenshot shows how to navigate the LabVIEW palette to get the random number generator.
In any event, from looking at your code, it appears as though you have some traditional DAQ VIs there.  In particular, you noted a problem with your LED's update frequency.  The problem could be due to screen updates.  Basically, you have a large front panel with many charts to update, and there will be thread swaps to the UI thread to handle corresponding updates.  Both the thread swap overhead, and the time that it takes to update the front panel will cause delays for the execution thread handling your DAQ functionality.  Check out the following example program I wrote to illustrate the time it takes to perform screen updates:
LabVIEW Execution Time and Screen Updates
I hope this helps explain the behavior!
Best Regards,
JLS
Message Edited by JLS on 03-27-2006 04:12 PM
Best,
JLS
Sixclear
Attachments:
Numeric Palette - Random Number (0-1).JPG ‏39 KB