Rockwell Automation 1756-CFM ControlLogix Configurable Flowmeter Module - Manual (Page 22)

22 Rockwell Automation Publication 1756-UM010B-EN-P - December 2011
22 Configurable Flowmeter Operation in the ControlLogix System
Listen-Only Connections
Any controller in the system can listen to the data from any CFM module
even if the controller does not own the module (in other words, it does not
have to hold the module’s configuration data to listen to the module).
During the CFM module creation process in RSLogix 5000 software, you can
specify the ‘Listen-Only’ Communication Format. For more information on
Communication Format, see
page 82 .
Choosing ‘Listen-Only’ mode allows the controller and module to establish
communications without the controller sending any configuration data. In this
instance, another controller owns the CFM module.
IMPORTANT
Controllers using the Listen-Only mode continue to receive
data multicast from the CFM module as long as a
connection between an owner and CFM module is
maintained.
If the connection between all owners and the CFM module
is broken, the module stops multicasting data and
connections to all ‘Listening controllers’ are also broken.