User manual

Transferring Data Using Communication Blocks
128
33002479 06 07/2008
Recommended
Actions
Take the following steps to protect against the unwanted effects of excessive
broadcast traffic:
Step Action
1 Reduce the speed of the port allocated to communicate with the respective
NOEs from 100Mb/s to 10Mb/s.
2 Limit the potential effects of an overloaded network to the NOE by filtering it with
an appropriate ConneXium switch set, with a limit of 500 packets per second.
(Schneider Electric offers a line of a configurable ConneXium switch, capable of
broadcast limiting.)
3 If the Ethernet switch must be set at 100Mb/s speed, the set the watchdog timer
to 1.5 seconds (independent of the number of NOEs). Otherwise, if the
watchdog timer is set too low, the the remaining system may also stop working
if a persistent overloaded network occurs.