Rockwell Automation 1747-SN Remote I/O Scanner - Manual (Page 11)

Publication 1747-UM013B-EN-P - January 2005
Overview 1-3
your application program requires. Configuration is done through the
confiGuration file (G file). Refer to Chapter 4, Configuration and
Programming, for more information.
Scanner I/O Image Division
The scanner allows each adapter to use a fixed amount (user defined)
of the scanner’s input and output image. Part of the SLC processor’s
image is used by local I/O, the other portion is used by the scanner
for remote I/O.
The scanner remote I/O image is divided into logical racks and further
divided into logical groups. A full logical rack consists of eight input
and eight output image words. A logical group consists of one input
and one output word in a logical rack. Each logical group is assigned
a number from 0 to 7.
IMPORTANT
The SLC 500 processor (SLC 5/02 or later) supports
multiple scanners in its local I/O chassis. The
maximum number is dependent on the following:
• backplane power requirements (power supply
dependent)
• SLC 500 processor I/O data table limit (4,096 I/O)
• processor memory to support the application
(SLC 500 processor dependent)
Processor I/O Image Scanner I/O Image Adapter
Image
Logical Group 7
Local I/O
Remote I/O
(Scanner Image)
Logical Rack 2
Logical Rack 1
Logical Rack 0
Logical Group 0