Installation guide

Network Infrastructure for EtherNet/IP™
A-4
Appendix A Recommendations for Ethernet Switches in EtherNet/IP Systems
Large-scale Control and Enterprise Networking
Application Range: Enterprise-connected control system or enterprise-integrated control system
REQUIRED:
1. All specifications included in Isolated Systems: General Use.
2. Web- or SNMP-accessible port utilization and bandwidth diagnostics: In systems
where enterprise connectivity and real-time control performance needs must be balanced, the
ability to see the percent of bandwidth utilization of each port allows a faster means of
locating traffic overload points. The RMON diagnostics can then be used to further dissect
the nature of the high traffic, and corrective action can be taken by changing VLAN, routing,
or other parameters.
RECOMMENDED:
3. For enterprise-connected applications without gateways, the use of industrial
switches with VLAN capability is recommended.
In this case, existing office (non-
industrial) routers may be used to manage the selected data transfer between the control
system and the plant network systems.
4. For enterprise-integrated applications, additional Layer 3 switches or routers are
recommended
to provide the real-time transfer of data while isolating disruptive traffic from
the control system and enterprise networks.
Application Notes:
See 6.4 Enterprise-Connected and Integrated Control Systems.
APPLICATION-SPECIFIC OPTIONS:
The functions noted here provide added performance or ease of maintenance. The actual need for these
and any associated cost versus functionality tradeoffs need to be evaluated for each application. Some of
the functions are still emerging in the industrial application range and may not yet have widespread multi-
vendor support. Generally speaking, the more of these functions a given switch has, the greater the range
of EtherNet/IP applications that can be addressed. Unless otherwise noted, the functions noted here relate
to applications using managed switches (isolated, general use systems and higher).
System Performance:
1. IEEE Std 1588 functionality for motion control applications coordinated with CIP
Sync:
In order to implement CIP Sync applications, switches must support IEEE 1588
functionality. See 6.4.1 Networks Connected via CIP Gateways and The EtherNet/IP
Specification
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for more information.
2. IEEE-based redundancy: IEEE Std 802.1D (Spanning Tree) and IEEE Std 802.1w (Rapid
Spanning Tree) provide redundant backbone connections and loop-free networks. These
previously separate standards have now been combined under the single IEEE Std 802.1D.
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ODVA, The CIP Networks Library, Vol. 1 and 2, The EtherNet/IP™ Specification. Ann Arbor: ODVA, Inc., 2006.
www.odva.org. CD-ROM.