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RCU internal database
and controls
This section details the data and controls
available in the RCU internal database.
Fusesaver data
Status data
Each Fusesaver has internal electronics
executing protection, controlling the
tripping and closing, measuring line current
and so on. The Fusesaver electronics send
Fusesaver status data every second to the
RCU over a short-range radio using a
communications module fitted to the
underside of the Fusesaver. This data is
called the live-data stream. The RCU uses
this live data to update the RCU internal
database so that this status data can be
then sent to a SCADA master station.
Fusesaver time-tagged events
In addition to the live data, the Fusesaver
generates time-tagged events such as
"protection trip" or "line current on." These
events are also sent over the short-range
radio to the RCU and can be passed on to
the SCADA master station as time-tagged
events. In this case, the event time provided
to the SCADA system is the time given by
the Fusesaver (in other words the time
which would be seen in the Fusesaver event
log).
When retrieving time-tagged events from a
Fusesaver, the RCU will discard events that:
Occurred before the communications
between Fusesaver and RCU were
established, or
Occur while communications between
Fusesaver and RCU have failed.
RCU data
In addition to the data from the Fusesaver,
the RCU itself generates status points in the
database, such as door open or battery end
of life. These points can also generate
events available to the protocol to be sent to
the SCADA system. In this case, the events
will have a time tag from the RCU internal
clock.
Data qualifiers
Data available in the RCU database may
have one of the qualifiers described below.
Refer to page 8 Table 2: Object flags for
details of how the qualifiers are used by the
DNP3 protocol. Changes to qualifiers will
generate events which are tagged by RCU
clock time.
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