Preface, Introduction, Preface introduction – Rockwell Automation 1756-RIO ControlLogix Remote I/O Communication Interface Module User Manual User Manual
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Publication 1756-UM534B-EN-P - November 2010
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Preface
Introduction
This manual describes how to configure and troubleshoot your Logix Remote
I/O (RIO) Communication Module.
The 1756-RIO module:
• runs in a ControlLogix environment.
• allows upgrade from PLC-5, PLC-3, or SLC systems to a ControlLogix
system with a minimum of downtime and startup time.
• uses integer data.
• does not require MSG instructions. All data is scheduled.
• offloads block transfer execution to reduce processing burden on the
processor.
This publication explains how and why you would use a 1756-RIO module.
The module is used in two modes, scanner and adapter mode.
In scanner mode, the 1756-RIO module enables communication and data
transfer between a ControlLogix controller and devices on a Remote I/O
network. The module continuously scans adapters on the remote network. The
module transfers discrete and block transfer data.
In adapter mode, the module performs two functions simultaneously. First, it
emulates one or more racks of I/O to a scanner, exchanging data with that
scanner. Second, it monitors other remote I/O racks on the same Remote I/O
network.
It can be used to upgrade an existing PLC-5, PLC-3, or SLC system to a
ControlLogix system.
The advantages of using the 1756-RIO module to upgrade your system
include:
• allowing the user to leave the existing Remote I/O network in place,
alleviating the time and/or expense of replacing the I/O and field
wiring, or the process of testing out field wiring.
• allowing the new application to be tested before you switch over, so that
it works just like the old one.
• allowing you to switch back to the old application in minutes, should
you run into problems.
For installation information, see the Remote I/O (RIO) Module Installation
Instructions, publication
.