May be the simplest thing is to change the mechanical behaviour on the button. Right-click on the control, then Mechanical action>Latch when released.
That should do the trick : When you press the button, it remains at True until read (means until the acquisition will be started in the case structure), and returns to false immediately after.
CC
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...