I had the same problem when I tried to figure out how to activate a solenoid from a button on a joystick. The examples were all activated from the front panel. I think you are having a similar problem. I was able to call ni and one of the engineers was able to walk me through it very quickly. Unfortunately, those phone lines have been severed by "the man" so we are at the mercy of this forum. The engineers are pretty good at reading them and helping out though.
As best as I can tell, here is your solution, keep in mind that I am pretty new to this stuff too.
• On the left side of the "while" loop you need 'open relay" vi (I had to put and open solenoid vi there). Inside the while loop put a "set relay" vi. Outside to the right place a "relay close "vi. On the relay open vi, choose to add a constant by right clicking over its inputs. Here you should be able to assign it to relay output 1,2,3,4 etc (the great thing about Labview is that you are limited to only choices that actually work). Wire the Devref output of the Open relay vi to the devref input of the set relay (inside the while loop) and then wire the devref output of the set relay to the input of the close relay vi outside the while loop.
• Assuming that you wish to activate the relay from a button on your joystick, on the left side of the while loop place a "joystick open" vi (it does not matter whether you already have and open joystick vi there even if it is for that joystick). On the left side of this vi, there is a place where if you hover over it with the mouse and right click the mouse you can choose "add constant." This allows you to assign the joystick to USB 1, 2, 3 or 4.
• Inside the while loop on the right side of the "joystick get" vi there is an output that you want to wire to an "unbundle by name" vi. This vi is located on one of the pallets of the WPI library but at this point I don't really remember where it is or exactly how to wire it to the output of the "joystick get" vi. From the unbundle by name you should be able to pull out the button that you want to assign to the relay (once again this part is fuzzy to me.). Then from the this button assignment you connect a wire to the left side of the the "set relay" vi.
• Connect the devrefs of the joystick and you should be in business.
I am including the file of my program which uses three joysticks to operate three motors with the third joystick's buttons assigned to solenoids. Take a look at it, I think what what you need to do is very similar to what I had to do with the solenoids.
good luck
