Rockwell Automation 1756-IF4FXOF2F ControlLogix High-speed Analog I/O Module - Manual (Page 22)

22 Rockwell Automation Publication 1756-UM005B-EN-P - January 2013
Chapter 2 High-speed Analog I/O Operation in the ControlLogix System
Listen-only Mode Any controller in the system can listen to the data from a high-speed analog I/O
module (input data or echoed output data) even if the controller does not own
the module. The module does not have to hold the module’s configuration data
to listen to the module.
During the I/O configuration process, you can specify a Listen-only mode in the
Communication Format field. For more information on Communication
Format, see
page 75 .
Choosing a Listen-only mode option allows the controller and module to
establish communication without the controller sending any configuration data.
In this instance, another controller owns the module being listened to and stores
the module’s configuration data.
IMPORTANT Controllers using the Listen-only mode continue to receive data multicast from
the I/O module as long as a connection between an owner and I/O module is
maintained.
If the connection between the owner and the module is broken, the module
stops multicasting data and connections to all listening controllers are also
broken.