. . . . . "In an enhanced or closed-loop configuration, the signposts 20 are connected with the central controller 12, as shown, with cable, LANS, Internet, IR, WI-FI, radio or other forms of direct communication, and the system can send outputs from the signpost 20 to one or more tags 18, then from the tags 18 to one or more receivers 22, and then to the controller system 12, and from the controller 12 to t" . . .