Hello.
I am not sure how you are getting the data from the encoder, but it
sounds like you could have a separate loop just for monitoring the
enconder, and generate the graph there. In other words, you could
have a loop with the event structure to handle all your buttons, and a
separate loop where you read the encoder, and continously update the
graph.
If you only want to update the graph when a button is pressed, you
could have an event structure inside this second loop and trigger the
event when any of the buttons are pressed.
Without knowing more about your application and VI structure, this is the best advice I can give you.
Hope this helps,
Alejandro