20 Rockwell Automation Publication 1756-UM058G-EN-P - November 2012
Chapter 2 Digital I/O Operation in the ControlLogix System
Ownership
I/O modules in a ControlLogix system can be owned by an RSLogix™ 5000 
controller. An owner-controller fulfills these functions:
• Stores configuration data for every module that it owns
• Sends I/O modules configuration data to define module behavior and 
begin module operation with the control system
• Resides in a local or remote chassis in regard to the I/O module’s position
Each ControlLogix I/O module must continuously maintain communication 
with its owner-controller to operate normally.
Typically, each module in the system will have only one owner-controller. Input 
modules can have more than one owner-controller. Output modules, however, 
are limited to a single owner-controller.
For more information about using multiple owner-controllers, see Configuration 
Changes in an Input Module with Multiple Owners on page 35.
Use RSNetWorx and 
RSLogix 5000 Software
The I/O configuration within RSLogix 5000 software generates the 
configuration data for each I/O module in the control system, including modules 
in a remote chassis. A remote chassis contains the I/O module but not the 
module’s owner-controller. A remote chassis can be connected to the controller 
via an EtherNet/IP network or a scheduled connection on the 
ControlNet network.
Configuration data from RSLogix 5000 software is transferred to the controller 
during the program download and subsequently transferred to I/O modules. The 
I/O modules in the local or remote chassis are ready to run as soon as the 
configuration data has been downloaded. However, to enable scheduled 
connections to I/O modules on the ControlNet network, you must schedule the 
network by using RSNetWorx™ for ControlNet software.
RSNetWorx software transfers configuration data to I/O modules on a scheduled 
ControlNet network and establishes a network update time (NUT) for the 
ControlNet network that is compliant with the desired communication options 
specified for each module during configuration.
Anytime a controller references a scheduled connection to I/O modules on a 
scheduled ControlNet network, you must run RSNetWorx software to configure 
the ControlNet network.