You can wire directly from a terminal outside a structure to a terminal inside the structure. LabVIEW creates a tunnel where the wire crosses the structure boundary. A tunnel allows data to flow in and out of loops and structures.
Avoid the following when wiring structures:
For constants wired to structures, LabVIEW uses constant folding to optimize performance. With constant folding, LabVIEW computes constant values on first run of the VI, instead of calculating them during each run. You can display constant folding of structures by selecting Tools»Options, selecting Block Diagram from the Category list, and placing a checkmark in the Show constant folding of structures checkbox. When you place a checkmark in the Show constant folding of structures checkbox, gray hash marks appear inside structures that are wired to constants. The hash marks might not appear until after you run or save the VI.