There is a function in the MINDSTORMS Module for LabVIEW that allows you to specify a particular NXT or EV3 connected to your computer. This is useful in Direct Mode only when you might have more than one brick connected (via USB or Bluetooth) and want different parts of your code to use particular functions (read sensors, move motors, etc) on a particular connected brick. This also allows the computer to act as a "middle man" between two bricks; e.g. read the second on one and move a motor on another based on the value.
Here is where the function is located. "MINDSTORMS Robotics -> I/O -> Direct Only" and the "Specify NXT/EV3" funtion is in hte bottom right. Wire into the top left of the function a string with the name of the brick you wish to use. (You can change the name of the brick with the NXT/EV3 Terminal tool.)
