[Alan Anderson]

It's not exactly obvious how to place a reference to an existing global variable. Here's how to do it:

Right-click on an empty spot in the block diagram to call up the function palette. Choose "Select a vi..." and navigate to the folder containing your robot project. Open "Robot Global Data.vi" and you'll have a global variable attached to your cursor (it will likely be named "Enable Vision" -- don't worry about it). Click to place that variable on the block diagram. Now you can click on the middle of the variable to bring up a list of all the globals that are part of the Robot Global Data vi. Choose the one you want.

The default is to make a "write" reference. To change it to "read", right-click on the variable and choose "Change To Read".