Rockwell Automation 1715-OF8I Redundant I/O System User Manual - Manual (Page 15)

Rockwell Automation Publication 1715-UM001C-EN-P - March 2014 15
Chapter
1
Redundancy System Overview
The 1715 Redundant I/O System lets a ControlLogix controller communicate to
a remote, redundant I/O chassis by using EtherNet/IP. The 1715 Redundant I/
O system provides fault tolerance and redundancy for critical processes by using a
redundant adapter pair and multiple I/O modules that have diagnostics and are
easily replaceable.
The modular architecture lets a system be built and adapted to suit the specific
needs of an installation. It lets the user to choose from different levels of adapter
and I/O fault protection.
The 1715 Redundant I/O System consists of a single, two-slot, adapter base unit
that houses a redundant adapter module pair. The adapter base unit is connected
to up to eight I/O base units, that can hold up to 24 I/O modules (three I/O
modules per I/O base unit) when connected together. The I/O modules can be
configured in any combination of simplex or duplex pairs, depending on the
mode of operation needed. The I/O base units can be connected directly to the
adapter base unit and other I/O base units, or through expansion cables.
The 1715 Redundant I/O System is a modular system in which the adapter and
I/O base units snap together by using mating connectors and retaining clips to
form the backplane. Modules can be removed and replaced without system
interruption. The base units, via termination assemblies, provide the
interconnections for power, adapter, and I/O data. Once connected, the base
units form the single, mechanical assembly, or backplane.
Redundant 1715 Adapter Modules
The redundant, partnered adapter modules monitor inputs/outputs and
diagnostics for the I/O in the remote chassis. If a fault occurs in one of the
redundant adapters, an IP address switchover occurs and I/O monitoring and
communication to the ControlLogix System continues without interruption.
This switchover is completely transparent to the user. Status indicators and status
information available to the ControlLogix application enables you to determine
the status of each 1715-AENTR adapter module.