Practical_modern_SCADA_protocols_-_dnp3,_60870-5_and_Related_Systems

Applications of DNP3 and SCADA protocols 385
DNP3 events
In order to minimize network congestion, consecutive messages are inhibited for a set
time to allow other devices to use the network (Min Unsol Event Tx Delay). When an
event happens at a site, this will often trigger a series of other events, so a short time delay
can also be set to allow all changes to be included in the one transmission (Notification
Event Delay).
The event object type that will be used by the RTU in RBE messages to the DNP3
master can be defined for each data type.
Some DNP3 masters can process multiple analog events for the same point, however
analog event buffer mode can be set to single if the master station does not permit this.
If no triggered events occur and the buffered events accumulate, they will eventually
cause an unsolicited message to the master when the number of events reaches Class x
Min Events.
Each class can be individually enabled or disabled by the DNP3 master station.