Ethernet Switch Types; Ethernet Switch Functions - Omron NJ Series User Manual

For 100Base-
TX
*1. We recommend that you use cables and connectors in above combinations.
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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 implement-
ed in the Ethernet switch as IGMP snooping or GMRP.
"Specific nodes" are nodes equipped with an IGMP client, and 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 multi-
cast 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
priority to a specific IP address or TCP (UDP) port. The TCP and UDP protocols are called trans-
port layer protocols, leading to the name L4 (layer 4) QoS function.
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User's Manual (W506)
Product
Size and con- Cable
ductor pairs:
AWG22 ×
*1
2P
RJ45 Assembly
Connectors
2 Installing Ethernet Networks
Manufacturer
Kuramo Electric Co., Ltd.
JMACS Japan Co., Ltd.
SWCC Showa Cable Systems
Co., Ltd.
OMRON
Model
KETH-PSB-OMR
PNET/B
FAE-5002
XS6G-T421-1
2
2-3