Adjusting Device Bandwidth Usage - Omron CJ1W-EIP21 Operation Manuals

12-2-3 Adjusting Device Bandwidth Usage

 Ethernet Switches without Multicast Filtering (100-Mbps Ethernet Switches)
• Is the network bandwidth without multicast filtering usage under 100 Mbps for each node?
If any node exceeds 100 Mbps, change the connections settings, such as the RPI.
• Is the usage of capacity without multicast filtering under 100% for each node?
If any node exceeds 100 Mbps, change the connections settings, such as the RPI.
• Is the total network bandwidth usage under 100 Mbps?
If the total bandwidth usage exceeds 100 Mbps, the bandwidth of part of the transmission path
(e.g., an Ethernet switch or media converter) may be exceeded as the result of how the network
was wired (e.g., cascade connections of Ethernet switches), causing a tag data link to operate
abnormally. Check the bandwidth of the transmission path for all cascade connections. If the
bandwidth is exceeded, rewire the network or increase the bandwidth between Ethernet switches
(e.g., to 1 Gbps). If these countermeasures are not possible, change the connection settings, e.g.,
the RPI settings, and adjust the bandwidth for all cascade connections until the total network
bandwidth is not exceeded.
 Ethernet Switches with Multicast Filtering (100-Mbit/s Ethernet Switches)
• Is the network bandwidth usage under 100 Mbps for each node?
If any node exceeds 100 Mbps, change the connections settings, such as the RPI.
• Is the usage of capacity under 100% for each node?
If any node exceeds 100%, change the connections settings, such as the RPI.
• Is the total network bandwidth usage under 100 Mbps?
If the total bandwidth usage exceeds 100 Mbps, the bandwidth of part of the transmission path
(e.g., an Ethernet switch or media converter) may be exceeded as the result of how the network
was wired (e.g., cascade connections of Ethernet switches), causing a tag data link to operate
abnormally. Check the bandwidth of the transmission path for all cascade connections. If the
bandwidth is exceeded, rewire the network or increase the bandwidth between Ethernet switches
(e.g., to 1 Gbps). If these countermeasures are not possible, change the connection settings, e.g.,
the RPI settings, and adjust the bandwidth for all cascade connections until the total network
bandwidth is not exceeded.
• Is the network bandwidth usage without multicast filtering under 100 Mbps for each node or the
usage of capacity without multicast filtering under 100% for each node?
If any node exceeds 100 Mbps or 100%, check whether the multicast filtering on the Ethernet
switch is functioning correctly. If the number of multicast filters on the Ethernet switch is less than
the total usage of IP multicast addresses, bandwidth overloads may occur in some paths and pre-
vent tag data links from operating correctly depending on the network connection (e.g., cascade
connections of Ethernet switches). Calculate the number of multicast filters required by each
Ethernet switch on the network and make sure that the number does not exceed the number of
Ethernet switch multicast filters. If the number of Ethernet switch multicast filters is not sufficient,
use switches with enough multicast filters or revise connection settings, such as the RPI settings.
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
12 Communications Performance and Communications Load
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