Abstract: A building automation system is provided in which a controller is connected to remote modules through a zone enclosure using RS-485 cables. Branches of modules extending from the zone enclosure are connected together by removable jumpers at the zone enclosure. Sets of branches of modules using different protocols are isolated from each other. Shorts in the RS-485 cables can be determined by disconnecting and reconnecting the branches from the network. The zone enclosure has a patch panel that contains modular RS-485 connectors. An RS-485 cable from the controller and pulled through the building along with other data cables is connected to the RS-485 connectors at the back of the patch panel. The modules are connected to the RS-485 connectors at the front of the patch panel through RS-485 cables.