You have three processes operating in parallel inside your loop -- setting the properties of your graph from the Time control, building and displaying the Waveform, and waiting 100 msec. All of these must take place before the While loop can do the next step. Which one of these goes first? Who knows? You don't sequence them, so the order is arbitrary.
The Wait is the simplest to dismiss -- it doesn't "do" anything except "wait" -- if the Wait starts before or after the Graph, it hardly matters. How about changing the scales and plotting the Graph? Well, here you might want to always do it in the same order, but I have no idea which you should do first. Note that if you make use of Error Lines, you can use them to sequence things that you want to take place in a particular order (most of your code uses functions without Error Lines -- the exception seems to be the Property Node for the Waveform Graph).
Here's another idea -- are you planning to do anything with your Array (which you only have after you stop the While loop)? If not, don't bother using an Array and a Graph, but simply plot the single "latest value" onto a Chart (which takes single points and scrolls those values across the Chart ...).
Bob Schor
