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Halytech
hydroSpider2 User’s Manual v1.23
Page 108
Appendix G3.
DNP3 alarms
When using a modem to connect to the DNP3 server, the hydrospider2 can periodically update the
server, as described above.
However, you may need you SCADA system to become immediately aware of certain input
conditions, such as a switch closing or a sensor input going above or below some threshold, instead
of having to wait for the next regular update.
You can do this by setting up an alarm as usual (see
), and selecting “DNP3 Alerts”
as one of the alarm alerting options:
When the alarm becomes active, the hydrospider2 will connect to the DNP3 master server and send
any unsent events (as unsolicited responses) to the server.
Because a DNP3 event is generated whenever an input changes, one of the events sent to the server
will be the most recent change which activated the alarm.
Note that a corresponding alarm must also be setup in the SCADA system.
The SCADA system will only see the new input level. There is nothing in a DNP3 event that marks it
as being any more special than any other event – they are all considered to be “interesting” and it is
up to the SCADA system to assign significance to them.
The hydrospider2 sends data about changed inputs to the DNP3 master. When a DNP3 alarm occurs
on the hydrospider2, the data will be sent immediately. But it’s always up to the DNP3 master to
interpret the data sent by an outstation.
To continue to send events while the alarm is active, select the “
Repeat (fast period)
” dropdown
menu option. The hydrospider2 will continue to connect, at the rate specified by the “Fast Period”