Installation guide

Network Infrastructure for EtherNet/IP™
A-2
Appendix A Recommendations for Ethernet Switches in EtherNet/IP Systems
Isolated Systems: Small Scale
Application Range:
Isolated control network with a single controller and a low device count
REQUIRED:
1. Speeds are 10 Mbps through 100 Mbps with full-duplex operation on all ports. Full-
duplex operation eliminates collisions, a key requirement for deterministic control.
2. LED diagnostics have a Link LED per port (a physical cable connection is
acceptable) and a network traffic activity indication per port.
The traffic indication
allows the user to differentiate between no traffic, intermittent traffic, and high traffic.
RECOMMENDED:
3. The switch auto-negotiates the data rate, the duplex settings, and provides auto-
crossover (MDI/MDX)
functionality to reduce device set-up requirements and cable
compatibility problems.
4. The switch supports a maximum operating temperature of 55° C (131° F) or higher.
5. The switch meets the IEC Std 61000-4 or equivalent standards for noise immunity
and emission.
Application Notes:
The primary use of these types of switches is for small applications (less than10 devices) with a small
number of CIP connections and slower RPIs, or applications that are lower cost extensions to IGMP-
enabled switches.
The above specifications relate to switches without IGMP snooping (unmanaged switches). Due to the
multicast operation of EtherNet/IP, one must either calculate the total multicast traffic to which each
connected unmanaged switch will be exposed or test the configuration in advance. Failure to do this may
result in devices overloaded with unwanted multicast traffic, which may cause communications to stop.
Isolated Systems: General Use
Application
Range: Isolated control network with a single controller and a high (more than 10) device
count, or an isolated network with multiple, interlocked controllers
REQUIRED:
1. All specifications included in Isolated Systems: Small Scale.
2. IGMP snooping: This provides for proper management of IP multicast traffic. More
specifically, it provides for fast consumer joins and leaves of multicast streams (reducing
memory use) and limits bandwidth-intensive IP multicast traffic to only those ports that are
intended to consume it.