Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 605)

Remote I/O Parameters
Chapter 33
33-5
Function
The parameter specifies if the remote I/O rack being simulated has the
highest starting module group address of any physical racks in the network.
Axis Parameter Number
Mill/Lathe Grinder
All [144] [149]
Range
Selection Result
(a) Not Last Rack
(b) Last Rack
Notes
The PLC system installer may be able to help you determine this value.
33.5
Adapter Last Rack Status