I want to write a test for the VI analyzer that only fails when a tunnel is used in the top or bottom of a structure in an "unacceptable" way. Other developers at my company agree with me that requiring all tunnels to only be on the left and right of structures is too strict. However, we aren't sure how to define what an "unacceptable" use of top/bottom tunnels is. Does anyone have any ideas of what the requirements for this should be? Perhaps defined by wire length? or what the resulting wire length would be if the tunnel was moved to the sides?
Any ideas or opinions on the usage of top/bottom tunnels are appreciated.
If you're going through the effort - top and bottom should not be allowed. Based on my experience, either these tunnels are after thoughts or there is just way too much going on within that diagram so it should be cleaned up.
I see nothing wrong with tunnels on all sides. I try to avoid tunnels that go through e.g. the case or event labels, etc.
(In fact I would prefer if the case selecter would also be allowed e.g. along the bottom edge of a case structure ;))
LabVIEW "best practices" would have you make tunnels on the sides only. That being said, unless they are being hidden by labels or other stuff, I think top and bottom are fine and actually helps the BD look cleaner (in most cases).
I forgot to add that I am HIGHLY biased towards side tunnels if the input and output tunnels are connected.
I know we all hate sequence structures, but if you do have a use case for flat sequence structures, you should allow top and bottom tunnels out of them, because it allows data to get out of the sequence before the entire sequence finishes. There is actually a difference in execution between running a wire all the way through to the last frame of a sequence, versus having it exit the sequence from the top or bottom in the frame in the last frame in which it's used.
nathand makes a good point. I see that as a functional point - much like using a conpane terminal on top or bottom of a subVI.
I am probably more compulsive than is truly healthy but I never use top or bottom tunnels on structures which do not require them.