Rockwell Automation 1747-SN Remote I/O Scanner - Manual (Page 4)

4 Remote I/O Scanner
Publication 1747-IN060D-EN-P - November 2002
Overview
The Remote I/O (RIO) Scanner, 1747-SN, enables communication between an
SLC™ processor and remotely located 1746 I/O chassis and other RIO-compatible
Allen-Bradley operator interface and control devices. The 1747-SN scanner
communicates with remote devices using the A-B Remote I/O link. The RIO link
consists of a single master (scanner) and multiple slaves (adapters). Communication
between devices occurs over twisted-pair cable with the devices daisy-chained
together. Maximum distance for remote communication is 3,048m (10,000 ft.). The
scanner is compatible with any standard RIO adapter device.
The SLC processor transfers a maximum of 4 logical racks (32 input and 32 output
image words) of discrete remote I/O data into the SLC input and output image files.
You can adjust the size of the scanner image files during configuration of your SLC
system so that the scanner only transfers the discrete I/O data required by your
application program. The 1747-SN Series B or later RIO Scanner can be configured
to transfer up to 64 words of data to a remote device via block transfer. Refer to
publication 1747-6.6, Remote I/O Scanner User Manual, for information on
configuration, programming, and block transfers.
The SLC 500™ processor (SLC 5/02 or higher) 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 input and output bits)
•
processor memory to support the application (SLC processor dependent)
SLC 5/02 or
later processor
RIO Scanner
(Master of the RIO Link)
1747-ASB Module
(Adapter/Slave)
Remote Chassis Remote Expansion Chassis
Local SLC Chassis
Dataliner™ Message
Display (Adapter/Slave)
PanelView™ Operator Terminal
(Adapter/Slave)
Redi PANEL™
(Adapter/Slave)