You've got no graphs on the main VI to update. Even if you did, the main would not get updated until the subVI finishes. That's basic LabVIEW.
One way to update indicators on the main (assuming you actuall have them), is to pass a reference to the subVI and inside the subVI, wire a value property to the reference and update that.
I also don't understand some of the things you've done in the subVI. You have some waveform charts but you are using the build array to write a new value and then wire the new array to the chart. That is not how you use a chart. Just wire the new value directly to the chart. A chart has a history and will have a scalar (not an array) as an input. The while loop in the middle with the True constant wired to the conditional terminal isn't required either. Send the command and if you need a wait, wire the error cluster to a Time Delay function.
