[Omar]

The JoySticks are assign USB number based on the serial number of each USB Joystick. Windows remembers which actual phyical joystick was assigned which USB# based on the serial number of the joystick.

So when you drag the joysticks around in the Diagnostics tab you are tell the system that you want the joystick with serial number XXXXXXXX to be USB1 and the joystick with serial number YYYYYYY to be USB2. So when in the Begin.VI you know which phyical joystick you are opening

You do not need to know the serial number the Diagnostics tab takes care of that.