User Manual Owner's manual

64 Rockwell Automation Publication 280E-UM001B-EN-P - July 2012
Chapter 3 Introduction to EtherNet/IP and Device Level Ring Technology
Number of Nodes on a
DLR Network
Rockwell Automation recommends that you use no more than 50 nodes on a
single DLR or linear network. If your application requires more than 50 nodes,
we recommend that you segment the nodes into separate, but linked, DLR
networks.
With smaller networks:
• there is better management of traffic on the network.
• the networks are easier to maintain.
• there is a lower likelihood of multiple faults.
Additionally, on a DLR network with more than 50 nodes, network recovery
times from faults are higher. For DLR networks with 50 or less nodes, ring
recovery time is less than 3 ms.
Ethernet Switches
Ethernet managed switches are key components that provide determinism and
the required throughput to achieve automation needs. Switches are able to
manage network traffic which reduces unnecessary delays or band width needs. A
properly designed EtherNet/IP infrastructure that implement segregation via
managed switch technology achieves a more reliable and secure network.
Ethernet Media
Today, unshield twisted pair (UTP) wiring is the standard in most applications
and allows for greatest flexibility and ease of installation and maintenance.
Category 5e (e-enhanced) cable is specifically designed to meet today’s
automation needs.
Standard RJ-45 connectors are not designed for industrial environments. For
outside the panel, IP67 connectors are required for EtherNet/IP.
Figure 46 - Network Media - Ethernet M12 D-Code Media