28 Rockwell Automation Publication 1715-UM001J-EN-P - December 2020
Chapter 1          Redundancy System Overview
For Ethernet considerations, see EtherNet/IP Network Configuration User 
Manual, publication ENET-UM001
, and ControlLogix Redundancy User 
Manual, publication 1756-UM535
.
Communication on the EtherNet/IP Network 
Communication to a simplex module is addressed to the slot number for that 
module. CIP communication to modules in a duplex configuration (including 
the adapters) is addressed to the lowest slot number for the module pair.
The adapters respond with CIP errors for attempts to communicate to an I/O 
module of a type that is not the same as the physically installed module.
The termination assembly type (simplex/duplex) determines the CIP messages 
for corresponding CIP objects that the adapter processes for each I/O module.
System Performance This section discusses connections and RPI settings for the 1715 Redundant I/O 
System.
Input / Output Traffic Prioritization
Note:In order to respect its IO schedule, the 1715 privileges class 1 (IO) traffic 
over class 3 traffic.
Connections
The adapter has one required connection and does not support a rack 
connection. 
Each I/O module has one required connection (simplex or duplex).
For example, the system in Figure 12
 has five I/O modules. Four are duplex and 
one is simplex. They are all configured for data connection.