Ethernet Switch Types; Ethernet Switch Functions - Omron NY532-5400 User Manual

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Ethernet Switch Types

 Unmanaged Layer 2 (L2) Ethernet Switches
These Ethernet switches use the Ethernet MAC address to switch ports. Ordinary Ethernet switches
have this function. Ethernet switch functions and settings cannot be changed.
 Managed Layer 2 (L2) Ethernet Switches
These Ethernet switches use the Ethernet MAC address to switch ports. Ethernet switch functions
and settings can be changed with special software tools for Ethernet switches running on a network
node. You can also collect analytical data. These Ethernet switches provide more-advanced func-
tions than unmanaged layer 2 Ethernet switches.
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Ethernet Switch Functions

This section describes the Ethernet switch functions that are important for an EtherNet/IP network. For
a built-in EtherNet/IP port, consider whether the Ethernet switch supports these functions when you
select the Ethernet switch.
• Multicast filtering
• QoS (Quality of Service) for TCP/UDP port numbers (L4)
 Multicast Filtering
Multicast filtering transfers multicast packets to the specific nodes only. This function is implemented
in the Ethernet switch as IGMP snooping or GMRP. "Specific nodes" are nodes equipped with an
IGMP client that have made transfer requests to the Ethernet switch. (OMRON built-in EtherNet/IP
ports are equipped with an IGMP client.) When the Ethernet switch does not use multicast filtering,
multicast packets are sent to all nodes, just like broadcast packets, which increases the traffic in the
network. Settings must be made in the Ethernet switch to enable this function. There must be
enough multicast filters for the network.
 QoS (Quality of Service) Function for TCP/UDP Port Numbers (L4)
This function controls the priority of packet transmissions so that packets can be sent with higher pri-
ority to a particular IP address or TCP (UDP) port. The TCP and UDP protocols are called transport
layer protocols, leading to the name L4 (layer 4) QoS function. When tag data links and message
communications are executed on the same network, tag data links can be sent at higher priority to
prevent problems such as transmission delays due to message communications traffic and packet
losses due to buffer overflow. Settings must be made in the Ethernet switch to enable this function
and give higher priority to tag data link packets.
Support for the above two functions is as follows for the different types of Ethernet switches.

Ethernet Switch Types

Unmanaged L2 Ethernet
switches
Managed L2 Ethernet
switches
OMRON W4S1-series
Ethernet switches
Additional Information
If the Network Configurator is used to set the connection type in the connection settings to a mul-
ticast connection, multicast packets are used. If the connection type is set to a point-to-point con-
nection, multicast packets are not used.
NY-series Industrial Panel PC / Industrial Box PC Built-in EtherNet/IP Port User's Manual (W563)
Multicast filtering
None
Provided.
None
2 Installing Ethernet Networks
L4 QoS
None ---
Provided. Both functions must be set
with a special software tool.
Provided. L4 QoS is set with a switch. No
software tool is necessary.
2
Remarks
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