The compressor tutorial on this website shows 2 blue rectangles, one that says “DIO 1” and one that says “Relay 1”. How does one get these rectangles in LabVIEW?
Right click on the terminal of the vi and it should bring up a menu in which you could create a constant.
Right, but how do I get it to have that grey triangle in the corner.
I’m sure you do not need that gray triangle. I think it’s marking that there is a comment on it, I need to check on that. I have set-up a compressor on my team’s robot and it is currently working fine.
Update: I just checked, the triangle should appear along with it, what does the drop down menu contain on the constant when you click on it?
The Grey triangle means it’s a Type Def.
I can’t see a reason why it wouldn’t appear 
Can you post a picture of what your’s looks like?