Rockwell Automation 1747-BSN Backup Scanner Module - Manual (Page 15)

1 Publication 1747-UM010B-EN-P - September 2003
Chapter
1
Overview
This chapter contains the following information:
•
system overview
•
how the backup scanner interacts with the SLC processor
•
how the backup scanner interacts with adapter modules
•
scanner I/O image concepts
•
extended node capability
•
complementary I/O
•
scanner features
•
compatible network devices
•
backup concepts for the SLC-500 system
System Overview The 1747-BSN Backup Scanner provides redundancy for:
•
Remote I/O (RIO)
•
RS232 channel switchover for communications to devices such
as operator interface
•
DH+
The backup scanner also provides a High Speed Serial Link (HSSL) to
write any retentative data from a primary to a secondary processor. In
addition, the module has a Local Serial Link (LSL) to pass status
information between multiple 1747-BSN modules located in the same
chassis (optional).
The 1747-BSN is a complementary set of modules, with one module
residing in the primary system and another module in the secondary
or backup system. The primary module controls the operation of
remote I/O, while the secondary module is available to take over
control in the event of a fault in the primary.
The backup scanner has the capability to switch between two
communication channels. The first channel is configurable as RIO or
DH+. The second channel is used to switch the RS232/485 channel in
order to provide connection for electronic operator interfaces. The
DH+/RIO and the RS232/485 channels can be used simultaneously.
The Remote I/O (RIO) scanner, Catalog Number 1747-SN, enables
communication between an SLC processor (SLC 5/02 or later) and