Omron Sysmac NX1P2-10 1 Series, User Manual

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When multicast filtering is used, settings must be made accordingly on the Ethernet switch. There
must be enough multicast filters for the network.

Executing Tag Data Links and Message Communications
We recommend an L2 Ethernet switch with multicast filtering and L4 QoS.
If you set tag data links for higher-priority transmission, it is possible to prevent problems such as
transmission delays due to message communications traffic and packet losses due to buffer over-
flow.
When multicast filtering and L4 QoS are used, settings must be made accordingly on the Ethernet
switch.
Selecting the Ethernet Switch Based on the Ethernet Switch's Sup-
ported Functions

L2 Ethernet Switch without Multicast Filtering
We recommend this kind of Ethernet switch when only tag data links are executed and any of the
following conditions is met.
• The tag data links are set to share the same data with all nodes in the network. (Multicast pack-
ets are transferred to all nodes in the network, just like broadcast transmission.)
• The tag data link settings are all one-to-one (unicast) and multicast packets cannot be used.
• There is little traffic in the tag data links.
No special settings are required for an L2 Ethernet switch without multicast filtering.

L2 Ethernet Switch with Multicast Filtering
We recommend this kind of Ethernet switch when only tag data links are executed and the follow-
ing condition is met.
• There are many 1:N links (where N represents some number of nodes in the network) in the tag
data link settings, i.e., there are many multicast packets used, or there is heavy traffic in the tag
data links.
Specific settings are required for an L2 Ethernet switch with multicast filtering. There must be
enough multicast filters for the network.

L3 Ethernet Switch with Multicast Filtering and L4 QoS Functions
We recommend this kind of Ethernet switch when both tag data links and message communica-
tions are executed.
If you set tag data links for higher-priority transmission, you can prevent problems such as trans-
mission delays due to message communications traffic and packet losses due to buffer overflow.
When multicast filtering and L4 QoS are used, settings must be made accordingly on the Ethernet
switch. There must be enough multicast filters for the network.
2 Installing Ethernet Networks
2-5
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User’s Manual (W506)
2-1
Selecting the Network Devices
2
2-1-4
Precautions for Ethernet Switch Selection