Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual - Manual (Page 88)

88 Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
Chapter 4 Configure the EtherNet/IP Network
2. Back-up Supervisor Node - An optional node that behaves like a ring node
unless the active supervisor node cannot execute required tasks. At that
point, the back-up node becomes the active supervisor node.
• Ring Node - A node that processes data transmitted over the network or
passes the data to the next node on the network. When a fault occurs on
the DLR network, these nodes reconfigure themselves, relearn the
network topology, and can report fault locations to the active ring
supervisor.
We recommend that you configure at least one back-up supervisor node
on the DLR network.
During normal network operation, an active ring supervisor uses beacon, and
other DLR protocol frames to monitor network health. Back-up supervisor and
ring nodes monitor beacon frames to track ring transitions between Normal and
Faulted states.
You can configure two beacon-related parameters:
• Beacon interval - Frequency at which the active ring supervisor transmits a
beacon frame through both of its ring ports.
• Beacon timeout - Amount of time that supervisor or ring nodes wait
before timing out the reception of beacon frames and taking appropriate
action.
IMPORTANT Although these two parameters are configurable, the default values
accommodate most applications.
We strongly recommend that you use the default values.