Rockwell Automation 1734-AENTR EtherNet/IP Network Configuration User Manual - Manual (Page 35)

Rockwell Automation Publication ENET-UM001L-EN-P - March 2014 35
Configure a Supervisor on a Device-level Ring Network Chapter 4
The ring supervisor provides these main functions:
• Manage traffic on the DLR network
• Collect diagnostic information for the network
Back-up Supervisor Node
At any point in time, there can be only one active supervisor on a DLR network.
However, we recommend that you can configure at least one other supervisor-
capable node to act as back-up supervisor nodes. During normal operation, a
back-up supervisor behaves like a ring node. If the active supervisor node faults,
the back-up supervisor with the next numerically highest precedence becomes
the active supervisor.
If multiple supervisors are configured with the same precedence value (the
factory default value for all supervisor-capable devices is 0), the node with the
numerically highest MAC address becomes the active supervisor.
We recommend that you execute these tasks:
• Configure at least one back-up supervisor.
• Configure the desired active ring supervisor with a numerically higher
precedence value as compared to the back-up supervisors.
• Keep track of the DLR network’s supervisor-precedence values for all
supervisor-enabled nodes.
For more information about how to configure a supervisor, see Configure
Supervisor Nodes on a DLR Network on page 37.
Ring Node
A ring node is any node that operates on the network to process data that is
transmitted over the network or to pass on the data to the next node on the
network. When a fault occurs on the DLR network, these reconfigure themselves
and relearn the network topology. Additionally, ring nodes can report fault
locations to the active ring supervisor.
IMPORTANT While a back-up supervisor is not required on a DLR network, we recommend
that you configure at least one back-up supervisor for your ring network.