Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 195)

Publication 1747-UM010B-EN-P - September 2003
Glossary 5
Input file
The scanner’s input image file that is updated during the SLC
processor input scan.
Local Expansion Chassis
A chassis that is connected to a local SLC chassis using a 1747-C9
(91.4 cm [36 in.]) or 1747-C7 (15.2 cm [6 in.]) cable.
Local SLC Chassis
The chassis that contains the SLC processor and scanner.
Logical Device
Any portion of a logical rack that is assigned to a single adapter.
Adapters may appear as more than one logical device.
Logical Group
A logical group consists of one input and one output word within a
logical rack. A word consists of 16 bits, each bit represents one
terminal on a discrete I/O module.
Logical Rack
A fixed section of the scanner image comprised of eight input image
words and eight output image words.
Logical Slot
A logical slot consists of one input and one output byte within a
logical group. A byte consists of 8 bits, each bit represents one
terminal on a discrete I/O module.
M files
The SLC M0 and M1 data files that reside in the scanner. M files
contain RIO network status (M1) and control (M0) information. The
contents of these files can be directly accessed by your application
program. Also, the M files are used to control and monitor RIO block
transfer operations.
Module Status Word (MSW)
This word is M1:s.3401 (where s=slot number of the 1747-BSN) and is
used to monitor the status of the 1747-BSN itself and its counterpart in
the remote system.