Adjusting Device Bandwidth Usage - Omron Sysmac NJ-series User Manual

14-2-3 Adjusting Device Bandwidth Usage

This paragraph provides the method to adjust the device bandwidth usage for tag data links.
Precautions for Correct Use Precautions for Correct Use
Ethernet switch must be corresponding to the maximum values of the network bandwidth, which
can be set to CPU Units. The maximum values of the network bandwidth per individual CPU Unit
are as follows.
• NX701 CPU Unit: 1,000 Mbit/s
• NX1P2 CPU Unit: 100 Mbit/s
• NJ-series CPU Unit: 100 Mbit/s
 Ethernet Switches without Multicast Filtering
• Is the network bandwidth usage without multicast filtering under the network bandwidth that can
be set for each node?
If any node exceeds its maximum network bandwidth that can be set, change the connections set-
tings, such as the RPI.
• Is the usage of capacity without multicast filtering 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 the network bandwidth that can be set?
If the total bandwidth usage exceeds the network bandwidth that can be set, 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 con-
nection 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
• Is the network bandwidth usage under the network bandwidth that can be set for each node?
If any node exceeds its maximum network bandwidth that can be set, change the connections set-
tings, 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 the network bandwidth that can be set?
If the total bandwidth usage exceeds the network bandwidth that can be set, 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 con-
nection 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 the network bandwidth that can
be set for each node or is the usage of capacity without multicast filtering under 100% for each
node?
If any node exceeds the maximum network bandwidth that can be set or the usage of 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 prevent tag data links from operating correctly
NJ/NX-series CPU Unit Built-in EtherNet/IP Port User's Manual (W506)
14 Communications Performance and Communications Load
14
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