Log data every 20 seconds with duration of 10 seconds

[stonecsu2000]

I am using Labview 8.20 on WinXP and trying to log data every 20 seconds with duration of 10 seconds. The hardware I am using is NI cDAS-9172 with NI 9237, NI 9205. I know it must be a simple programming, but I am just a beginer and need this shortly.  The attached vi file I wrote could not do what I want. Somebody please help me out. Thanks alot. 

[smercurio_fc]

I only took a brief look at your VI, but right off the bat, you need to get rid of your inner loop. The way it is once the "time to log" comes up you go into the inner loop and don't get out of the inner loop until the second elapsed time has happened. During this time you are not acquiring data - you're always logging the same value for 10 seconds..

[smercurio_fc]

Attached is an alternate implementation using simulated data. The string control acts as the data that's going to be logged.

It's crude, but I'll leave it to you to "spiff it up" or think of a more elegant solution.