Here is his diagram from the VI above (or a slightly condensed version).
A few quick answers without having read every post in this thread completely.
The reason the bottom one is yellow is that you probably right-clicked it at one point and said "Open Front Panel". At that point, there is a message indicating that you will no longer be able to double-click it to configure it, etc. Also, you saved it you disk as "Untitled 2.vi", but I didn't have that VI on my machine, which is why it appears to be "grayed-out". Normal Express VIs that can still be configured are blue, and stored within their calling VI (i.e. MainPollingLoop1.vi). Normal VIs (which is what they become once you "Open Front Panel" on an Express VI) are stored separately on disk.
Now like Dennis said, the tunnels on the for loop, by default, enable indexing, which creates an array of the data from each loop iteration. You rarely, if ever, really want to deal with an array of Dynamic Data. Trust me on this one. I suspect what you want is more like what's in the second picture. I used a shift register instead of the tunnels, and an Append Signals Express VI.
Hope this helps!
Jeff
Message Edited by Jeff B on 02-16-2007 08:34 AM