Without seeing any code, here are some comments based on LabVIEW itself.
- Take your code that "works" to take some data (at whatever data rate, and for however long you find useful). Have it write that data to a file, and consider giving the file a name that includes, say, the time the data were saved.
- Make that code a sub-VI. This is easy -- it is already a VI, all you have to do is provide an Error Line In and Out (the usual way to tie LabVIEW VIs together) and make sure the original VI can run without requiring "manual intervention" (i.e. you don't have to push a Start or Stop button). If you do have a Start button, just change the VI so it starts without waiting for the button, and if you have a Stop, replace that by stopping after N samples (you determine N).
- Now write a second VI that has a "Do until I tell you to Stop" (or "Until an hour is up") loop. Inside the loop put a call to your Sample sub-VI and a Wait function to govern how long you want to wait before taking another set of samples.
Note that if you look at the VI you wrote in Step 3, there's nothing there that says anything about writing files, sampling data, etc. -- it has all been "buried" (or, as is more proper to say, "encapsulated") in the sub-VI. This way, you can look at the top level VI, which is concerned only with taking the multiple readings you want, while the lower sub-VI doesn't care about repetitive readings, it only is concerned about its little sampling task. Divide and Conquer!
BS
