Patch Panels

A patch panel or patch bay is a panel, typically rack mounted, that houses cable connections. One typically shorter patch cable will plug into the frontside, whereas the back holds the connection of a much longer and more permanent cable. The assembly of hardware is arranged so that a numberof circuits, usually of the same or similar type, appear on jacks formonitoring, interconnecting, and testing circuits in a convenient,flexible manner.

It is conventional to have the top row of jacks wired at the rear to outputs and bottom row of jacks wired to inputs. Patch panels may behalf normal (usually bottom) or full-normal, "normal" indicating that the top and bottom jacks are connected together internally. When a patch panel has half-normal wiring, then with no patch cord inserted into either jack, the top jack is internally linked to the bottom jack via break contacts on the bottom jack; inserting a patch cord into the top jack will take a feed off that jack while retaining the internal link between the two jacks; inserting a patch cord into the bottom jack will break the internal link and replace the signal feed from the top jack with the signal carried on the patch cord. If a patch bay is wired to full-normal, then it includes break contacts in both rows of jacks.