Power Cab and cab addresses explained

Each Cab in an NCE DCC system must have it's own unique cab address.

The Power Cab default Cab address is 2. Do not change this unless you are using it with a booster or have multiple Power Cabs on the same layout. 

The Power Cab is ALSO a complete DCC system. The DCC system running your layout determines the valid cab addresses you can use. The ONLY valid cab addresses for cabs on a Power Cab layout are 2, 3, 4, and 5.

Note** Cab Id 5 is only available with firmware 1.65. 

Cab Id’s 6 are 7 reserved.

Use 8, 9, or 10 for other cab bus devices only. (USB, AIU, etc...)

https://ncedcc.zendesk.com/hc/en-us/articles/201492225-Change-Check-or-Reset-a-Cab-Address-on-a-Power-Cab-or-Pro-Cab