The AIU uses a cab address just like a regular cab.
The available cab address range is based on The DCC System Command Station that is running the layout.
DCC Twin: 0 and 1 are used by the twin / 2- 7 for additional cabs / 8, 9, 10 cab bus for devices only (AIU, mini panel, USB)
Power Cab: Address 2 is used by the Power Cab itself. When in Power Cab mode the address is forced to 2. Use cab addresses 3, 4, 5 for the other throttles or cab bus devices (6,7 reserved) 8,9, 10 cab bus for devices only (AIU, mini panel, USB)
SB5 can use cab addresses 2- 7 for throttles or cab bus devices / 8, 9, 10 cab bus for devices only (AIU, mini panel, USB)
PH-Pro Power Pro system 2 - 63 throttles (62 wired cabs total)
Additional considerations for wireless cabs:
A maximum of 16 wireless Pro Cabs using cab addresses: must use 2-17
All other wireless cabs can also use 2 – 49. preferred 18 – 49 to reserve lower numbers for Pro Cabs.