13 may have u201c mac m 1 1 u201d and a unitary controller 15 which also is connected to line 13 may have u201c mac m 2 2 u201d other unitary controllers may be connected to line 13 a new device instance for unitary controller 14 may equal u201c d g m g u2212 120 100 m 1 1001 u201d the new device instance for unitary controller 15 may equal u201c d g m g u2212 120 100 m 2 1002 u201d other new device instances which follow in the same manner may equal 1003 1004 1000 n where n is a total number of unitary controllers on line or network 13 the network needs to be configured as in the following first global controllers that are to support auto addressing should have for example an ms tp mac address in the range 120 127 the unitaries may look for an u201c i am u201d message from mac address 120 127 to determine what their own device instances should be not having any device with an ms tp mac address in the range 120 127 effectively disables the feature for that ms tp network second unitary controllers that support this feature will not communicate if they have a mac address in the.