ProSoft Technology 5201-MNET-101S - Manual (Page 99)

IEC-101 Slave ♦ ProLinx Communication Gateway Reference
IEC 60870-5-101 v3 Slave (Firmware version 3.xx) Protocol Manual
ProSoft Technology, Inc. Page 99 of 159
August 6, 2010
5.2.6 Events
In order to improve the communication efficiency, most applications will require
the Master to periodically poll for data changes with a higher priority than polling
for monitor data. Every time data change occurs, the slave should send this
information, typically with the date and time information on when the data change
occurred.
The following illustration shows the event communication between the Master
and the gateway during unbalanced mode:
The gateway can queue up to 99 events per data type. When the queue is full,
the oldest event will be deleted each time a new event is added to the queue.
You must configure the Master to poll the event queue frequently enough to
avoid losing events.