Rockwell Automation Publication 1715-UM001J-EN-P - December 2020
13
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 you build and adapt a system to suit the specific
needs of an installation. The architecture lets you choose from different levels
of adapter and I/O fault protection.
The 1715 Redundant I/O System consists of a two-slot adapter base unit that
houses a redundant adapter pair. The adapter base unit is connected to up to
eight I/O base units, which 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. One module in a duplex pair 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 Adapters
The redundant, partnered adapters 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 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.
1715 I/O Modules
Both digital and analog I/O modules are available for use in this system,
depending on your needs. I/O modules can be used singly or in pairs,
providing configuration in either Simplex or Duplex modes.