A Building Automation System (BAS) includes at least one Direct Digital Control (DDC) controller operating as a BACnet MS/TP master considered to be an “Anchor”. The Anchor operates an algorithm or method which automatically assigns BACnet Protocol MS/TP Media Access Control (MAC) addresses to other BAS components (considered Nomads) being installed into the network. The Anchor gathers MAC addresses existing on the MS/TP network, and issues an available MAC Pool Announcement. Each Nomad randomly picks a temporary MAC address. When the Anchor verifies singular communication at the temporary MAC address, the Anchor assigns a permanent MAC address to the Nomad, which can later be locked into flash memory. Using the preferred algorithm and method, Nomad devices are automatically assigned unused MAC addresses to join the MS/TP network in a non-conflicting, orderly way, with all communications occurring within the confines of BACnet MS/TP Protocol.