The Event Poll is all the event data that has changed since the last successful report, which may have been an unsolicited message from the slave or an event poll from the master. If an event category is not assigned a class in the slave, change events will not be reported.
Note: The DNP drivers do not change a DNP slave's configuration. It is the operator's responsibility to configure the DNP slave to properly report changes in response to event polls or unsolicited messages. Users may only actively enable or disable unsolicited messages in a slave's configuration. For more information, refer to the slave device's documentation.