Good morning Tom
It sounds like you have the basic functionality of your program. However you need to set the mechanical action of the boolean to "latch when pressed".
(without your code I can't be certain but it's worth a try)
If you right click the boolean switch you use to bring up the dialog box, select mechanical action, and any latch function should work for you.
This will read the boolean value change once and then reset the switch back to False.
This should solve your problem (if I am picturing your code correctly)
Please post back with the code if this doesn't solve the problem and I will (as I'm sure Altenbach will too) try and find a solution for you.
Thanx
AdamB
Applications Engineering Team Leader | National Instruments | UK & Ireland