One of the reasons I dislike Express VIs, particularly for beginners who are trying to learn LabVIEW on their own, is that it "hides" what is going on. Similarly, those Dynamic Wires (or whatever they are called) all look the same, but can contain vastly different types of data, further confusing the situation.
There is an excellent NI White Paper on DAQmx that shows how you can do 80% of everything you need to do with DAQmx using only 10 DAQmx functions (its name is something like "Use 10 DAQmx Functions and do 80% ..."). What you get from this is a LabVIEW Wire that follows the color-code and form to allow you to instantly identify if the wire carries Floats or Integers or Booleans, is a single number, a 1D array, or a 2D array. Similarly, if you want to take the RMS of a 1D array and wire in a 1D array of reals, you will see (just by looking at the wire) that what comes out is a real scalar (a single value). This would have made it clear that if you generate 1000 points/second and reduce them to a single point, you will get out 1 point/second, which is what you observe.
Bob Schor
