Allen-Bradley PLC-5 User Manual page 128

8-10 Communicating with Extended-Local I/O
Remote
Rack ## Starting
Group
4 0
5 0
Publication 1785-UM012D-EN-P - July 2005
How Chassis Size and Backplane Addressing Determine the Quantity of I/O Racks
If You are Using this And 2-Slot
Chassis Size Addressing
(Single Density)
4-slot 1/4 logical rack
8-slot 1/2 logical rack
12-slot 3/4 logical rack
16-slot 1 logical rack
On the extended-local-I/O scan list, the actual chassis size and
backplane addressing is displayed, not the rack size.
The scan list for extended local I/O has one entry for each physical
chassis on the extended local I/O channel.
If an adapter on a remote I/O channel resides in a physical chassis that
contains more than one I/O rack, more than one entry appears on the
remote I/O scan list for that single chassis.
The following table shows the scan list for both remote I/O and
extended local I/O. Each channel shows a 16-slot chassis using 1-slot
addressing with a starting address of rack 4, module group 0. This
chassis contains logical racks 4-5.
Remote I/O Scan List vs Extended-local I/O Scan Lis
Rack Range
Size
FULL 040-047
FULL 050-057
A scan list includes the following:
Or 1-Slot Addressing
(Double Density)
1/2 logical rack
1 logical rack
11/2 logical rack
2 logical racks
Extended
Rack Starting Chassis
Address Group
4 0
Or 1/2-Slot
Addressing
(Quad Density)
1 logical rack
2 logical racks
3 logical racks
4 logical racks
t
Backplane
Size Addressing
16-SLOT 1-SLOT
Range
040-057