Type	Description
0	Network Software and Services
1	Locomotives
2	Ground Host Processes (Dispatch, Maintenance)
3	Wayside Devices - Wireline-connected
4	Mobile Addresses (Work Crews, Hi-Rails)
5	Wayside Devices - RF-connected
6	Trucks and Personal Portable Terminals
7	Wayside Devices - RF-connected
8-9	Reserved for Expansion

The next three digits of the address represent the AAR-assigned railroad number: (a more complete listing may be found here).

 

Number	Railroad
022	Atchison Topeka Santa Fe
340	ATCS Shared Network
400	Kansas City Southern Railway Company
721	Southern Pacific Transportation Company
802	Union Pacific Railroad Company

The meaning of the remaining digits varies by Address Type:

 

Address Type	Format	Description
0,2	NN	Network Node Number
	DDDD	Addressed Device Identifier
1,4	XXXX	Locomotive or Work Crew Number
	DD	Addressed Device Identifier
3,5,7	XXXXXX	WIU / Control Point ID
	DD	Device Number
	XX	Object Number
6	XXXXXXXX	Truck or Terminal Number
	DD	Addressed Device Identifier