Rockwell Automation 57C423 Common Memory Module - Manual (Page 19)

4Ć3
4.2.1 Rack Slot Restrictions
A Common Memory module is required in slot 0 in a rack that
contains more than one Processor module. The slot to the right of the
Common Memory module must either be empty or contain a
Processor module for M/N 57C413B. For M/N 57C423, the 3 slots to
the right of the module must either be empty or contain a Processor
module.
This module may also be plugged into even slots (2,4,6,8,10,12, or
14). Since the 128K bytes (64K registers) of memory available (for
both modules in a nonĆ0 slot)require two slots of address space, the
slot to the right of the Common Memory module must be empty.
4.2.2 Remote Racks
This module cannot be used in a remote I/O rack.