H-12 Distributed Network Protocol (DNP) V3.00 Date Code 20001006
SEL-351 Instruction Manual
the original element and add that to get the point index. Binary Inputs 500 - 999 are derived from
the Sequential Events Recorder (SER) and carry the time stamp of actual occurrence. Static reads
from these inputs will show the same data as a read from the corresponding index in the 0 - 499
group. Only points that are actually in the SER list (SET R) will generate events in the 500 - 999
group.
Analog Input (objects 30 and 32) are supported as defined by the preceding table. The values are
reported in primary units. Analog inputs 28 - 35, 42 - 57, 64 - 79, 86 - 104, and 106 are further
scaled according to the DECPLM setting (e.g., if DECPLM is 3, then the value is multiplied by
1000). Analog inputs 58 - 63, 80 - 85, and the even-numbered points in 0 - 7 and 16 - 21 (current
magnitudes) are scaled according to the DECPLA setting. The even-numbered points in 8 - 15 and
22 - 27 (voltage magnitudes) are scaled according to the DECPLV setting. Analog inputs 36 - 41,
108, and the odd-numbered points in 0 - 27 (angles) are scaled by 100. The remaining analogs are
not scaled. Event-class messages are generated whenever an input changes beyond the value given
by the ANADB setting. The dead-band check is done after any scaling is applied. The angles (the
odd numbered points in 0 - 27) will only generate an event if, in addition to their dead-band check,
the corresponding magnitude (the preceding point) contains a value greater than the value given by
the ANADB setting. Analog inputs are scanned at approximately a 1-second rate, except for
analogs 105 - 113. During a scan, all events generated will use the time the scan was initiated.
Analogs 105 - 113 are derived from the history queue data for the most recently read fault and do
not generate event messages. Analog 105 is a 16-bit composite value, where the upper byte is
defined as follows:
Value Event Cause
1 Trigger command
2 Pulse command
4 Trip element
8 ER element
And the lower byte is defined as follows:
Value Fault Type
0 Indeterminate
1 A-Phase
2 B-Phase
4 C-Phase
8 Ground
The lower byte may contain any combination of the above bits (e.g., a 6 is a B to C fault and a 9 is
an A to Ground fault). If Analog 105 is 0, fault information has not been read and the related
analogs (106 - 113) do not contain valid data.
Control Relay Output Blocks (object 12, variation 1) are supported. The control relays correspond
to the remote bits and other functions, as shown above. The Trip/Close bits take precedence over
the control field. The control field is interpreted as follows:
Courtesy of NationalSwitchgear.com
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