Allen-Bradley 1747-SN - Scanner I;O Image Division

1–3Overview
Publication 17476.6 - July 1996
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.
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
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.