If you have a re-entrant VI in each plot window, then they are NOT showing the same data. The re-entrant attribute means that each copy of the VI has its own data space. In your sine-wave example, the results might be the same, but it's really two (or 3, or 4...) copies of the same data - not multiple views of a single pile of data.
If all your windows are identical in function (mine weren't, but in your example yours were), then you want to put as much code into a common VI as possible. I'm not sure what your end result is trying to accomplish, but if I were trying to allow each window to look at a different channel, then I would have the main store data for all channels) into the global function, and have each window call that function with a request for channel 2's data or channel 3's data or channel 2 vs. channel 3 in X-Y format. Make the global function do the work of extracting the requested data and assembling it into a plot. The plot window then just calls the global function with a request to get channel X, and puts the result into a graph. Long story short: Put as much code and data as you can into a common place, leave as little as possible in the multiple copies that are showing. <i> really wish I could mail you a thank you card or something you have been a life saver.=A0 Thank you so much!=A0 I will keep learning so maybe one day I could help you."</i><p> Your payment will be to stay on the forum and answer somebody else's questions now and then.
