Here is one of the coolest things about LV, and one of its major advantages over languages like VB - it has automatic memory management and it compiles whenever you make a change. This allows you to be very free in the way you handle data and change your code. In this case, you should note the small gray dot that appears when you wire the dynamic data into the Array of Waveforms input. This gray dot means that LV coerces the source data type (DDT, in this case) to the target data type (Array of waveforms). If it wouldn't match, you would get a broken wire, the VI couldn't run, and if you hover over the wire or press the broken run button you would get an exact description of the error. Cool, eh?
This can also be seen in other things. For example, you can change an array's data type or number of dimensions by simply doing it. This will automatically be reflected anywhere the array is called in the program, and if anything won't match, the VI will be broken. If you change the # of dimensions of an array, any array function which that array is wired to will adapt. This allows you to be very safe in the way you write code, because you have LV watching all that annoying stuff for you. You don't have to worry about misspelling a variable here (for the most part).
One important point about coercion - it does take processor power. This will usually only be evident in large arrays or loops, but it is an important point. Another thing is that coercing numeric types can cause you to lose data - coercing a DBL to a U16, for example, will cause you to lose all the fractional data.
To learn more about LabVIEW, I suggest you try searching this site and google for LabVIEW tutorials. Here and here are a couple you can start with. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide and the LabVIEW user manual (Help>>Search the LabVIEW Bookshelf).
___________________
Try to take over the world!
