User manual

Publication CNET-UM001C-EN-P - November 2005
Control I/O 4-9
Choose the Type of Ownership for a Module
Table 4.5 Choose the Type of Module Ownership
There is a noted difference in controlling input modules versus controlling
output modules
Table 4.6 Module Ownership Control
If The Module Is An And Another Controller And You Want To Then Use This Type of Connection
Input Module Does not own the module Owner, such as: not listen-only
Owns the module Maintain communication with the
module if it loses communication with
the other controller
Owner, such as: not listen-only
Use the same configuration as the other
owner controller.
Stop communication with the module if
it loses communication with the other
controller
Listen-only
Output Module Does not own the module Owner, such as: not listen-only
Owns the module Listen-only
Controlling This Ownership Description
Input Modules Owner The controller that establishes an owner connection to an input module configures that
module. This configuring controller is the first controller to establish an owner connection.
Once a controller owns and configures an input module, other controllers can establish
owner connections to that module. This lets additional owners to continue to receive
multicasted data if the original owner-controller’s connection to the module breaks. All other
additional owners must have the identical configuration data and identical communication
format that the original owner controller has, otherwise the connection attempt is rejected.
Listen-only Once a controller owns and configures an input module, other controllers can establish a
listen-only connection to that module. These controllers can receive multicast data while
another controller owns the module. If all owner controllers break their connections to the
input module, all controllers with listen-only connections no longer receive multicast data.
Output Modules Owner The controller that establishes an owner connection to an output module configures that
module. Only one owner connection is allowed for an output module. If another controller
attempts to establish an owner connection, the connection attempt is rejected.
Listen-only Once a controller owns and configures an output module, other controllers can establish
listen-only connections to that module. These controllers can receive multicast data while
another controller owns the module. If the owner controller breaks its connection to the
output module, all controllers with listen-only connections no longer receive multicast data.