Monitor Communication Module Statistics
Use the diagnostic webpages for communication modules to monitor the following statistics:
- CPU usage
- Connections used
For information about how to access the diagnostic webpages, see the ControlLogix EtherNet/IP Network Devices, publication 1756-UM004.
CPU Usage
The CPU usage of the
EtherNet/IP™
modules must be at 80% or less. CPU usage below 80% reserves enough CPU functionality for the EtherNet/IP™
module to facilitate a switchover.If the CPU usage is above 80%, the secondary chassis can fail to synchronize with the primary chassis after a switchover occurs. Unscheduled communication can be slowed.
If you must reduce the CPU usage of your
EtherNet/IP™
modules, consider making the following changes:- Review the Requested Packet Interval (RPI) of your connections.
- The RPI rate of a connection affects the loading on the associated communications modules.
- Before changing RPI rates, see the guidelines for I/O modules in the Logix 5000 Controllers Design Considerations Reference Manual, publication 1756-RM094.
- Reduce the number of devices that are connected to your module.
- Distribute the load by adding more communications modules, seven maximum, to the redundant chassis pair.
- Configure digital I/O with rack-optimized connections instead of direct connections.
- Take steps to reduce your CPU utilization. See the EtherNet/IP Network Devices User Manual, publication ENET-UM006.
Connections Used
If you go online with a controller through an
EtherNet/IP™
module that is near its connection limit, you can experience difficulty. The process of going online consumes another connection from the EtherNet/IP™
module. You can also experience difficulty when you add modules to the system.Provide Feedback