B3 going offline and logging multiple 0x1408s in its error log.
- b3 Controllers
Excessive traffic on the network causes controller to run out of message buffers.
Every time a controller receives a communication packet it has to allocate a block of memory (a buffer) to place the packet until it can be processed. Under normal network conditions the packets are processed at a rate that exceeds the rate at which they are coming in, in some cases typically associated with network configuration issues or malfunctioning nodes on the network, (i.e. broadcast storms) the firmware in the controller is unable to keep up with the amount of packets being received which exhausts message buffers available and renders the controller unable to communicate properly.
In many cases the condition is temporary and does not result in a major problem, it is not unusual to see sporadic 0x1408s in the error log but when the condition persists for longer periods it will have an impact on the ability of the controller to communicate properly on the network.
- Use LAN captures to identify and remove the root cause of the excessive traffic.
- Take steps to reduce the occurrence of many concurrent trend data requests being made of the b3 controller such as staggering trend collection times, varying log-intervals or configuring some logs as COV (interval = 0).
- Adjust the configuration to collect fewer trend records more frequently.