Scanner I/O Image Division - Allen-Bradley 1747-SN User Manual

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 0–7.
Local I/O
Logical Rack 0
Logical Rack 1
Remote I/O
(Scanner Image)
Logical Rack 2
Processor I/O Image
The scanner image contains the image of each adapter on the RIO
link. The adapter is assigned a portion of the scanner image, which
is referred to as the adapter image.
Overview
Logical Group 0
Logical Group 7
Scanner I/O Image
Publication 1747 6.6 - July 1996
1–3
Adapter
Image