Manual

Publication 1756-UM009C-EN-P - December 2010 21
Chapter 2
Analog I/O Operation in the
ControlLogix System
Introduction
I/O modules are interfaces between the controller and the field devices that
comprise the ControlLogix system. Analog signals, which are continuous, are
converted by the module and used by the controller to mandate field-device
results.
This chapter describes how analog I/O modules operate within the
ControlLogix system.
Ownership
Every I/O module in the ControlLogix system must be owned by a
ControlLogix controller. This owner-controller:
• stores configuration data for every module that it owns.
• can be local or remote in regard to the I/O module’s position.
• sends the I/O module configuration data to define the module’s
behavior and begin operation within the control system.
Each ControlLogix I/O module must continuously maintain communication
with its owner to operate normally.
Topic Page
Ownership 21
Using RSNetWorx and RSLogix 5000 Software 22
Direct Connections 23
Input Module Operation 24
Input Modules in a Local Chassis 24
Real Time Sample (RTS) 24
Requested Packet Interval (RPI) 25
Input Modules in a Remote Chassis 27
Output Module Operation 29
Output Modules in a Local Chassis 29
Output Modules in a Remote Chassis 30
Listen-only Mode 32
Multiple Owners of Input Modules 33
Configuration Changes in an Input Module with Multiple Owners 34