D.20
SEL-787 Relay Instruction Manual Date Code 20150130
DNP3 Communications
DNP3 Documentation
Default Binary Inputs
The SEL-787 dynamically creates the default Binary Input map after you
issue an R_S command. The SEL-787 uses the Part Number to determine the
presence of Digital Input cards in slots 3, 4, and 5. If present, each digital
input point label, INx0y (where x is the slot number and y is the point), is
added to the default map in numerical order.
Default Analog Inputs
The SEL-787 dynamically creates the default Analog Input map after you
issue an R_S command. The SEL-787 first checks for a voltage option in the
part number, and if voltages are present, adds IN_MAG, VAB_MAG,
VBC_MAG, VCA_MAG, VAVE_MAG, 3V2_MAG, P, Q, S, and PF to the
default DNP map. The SEL-787 then uses the Part Number to determine the
presence of Analog Input cards in slots 3, 4, and 5. If present, the SEL-787
adds each analog input point label, AIx0y (where x is the slot and y is the point
number), to the default map in numerical order to the DNP map.
Device Attributes (Object 0)
Table D.10 includes the supported Object 0 Device Attributes and variations.
In response to Object 0 requests, the SEL-787 will send attributes that apply to
that particular DNP3 session. Because the SEL-787 supports custom DNP3
maps, these values will likely be different for each session. The SEL-787 uses
its internal settings for the following variations:
➤ Variation 242—FID string
➤ Variation 243—Part Number
➤ Variation 245—TID setting
➤ Variation 246—RID setting
➤ Variation 247—RID setting
➤ Variation 248—Serial Number
Variation 249 shall contain the DNP subset and conformance, “2:2009”.
Variation 250 shall contain the product model, “SEL-787” and variation 252
shall contain “SEL”.
Binary Inputs
Binary Inputs (Objects 1 & 2) are supported as defined by Table D.11. The
default variation for both static and event inputs is 2. Only the Read function
code (1) is allowed with these objects. All variations are supported. Object 2,
Variation 3 will be responded to, but will contain no data.
Binary Inputs are scanned approximately once per second to generate events.
When time is reported with these event objects, it is the time at which the
scanner observed the bit change. This can be significantly delayed from the
time when the original source change occurred and should not be used for
sequence-of-events determination. Binary inputs registered with SER are
derived from the SER and carry the time stamp of actual occurrence. Some
additional binary inputs are available only to DNP. For example, STWARN
and STFAIL are derived from the diagnostic task data. Another binary input,
STSET, is derived from the SER and carries the time stamp of actual
occurrence. Static reads of this input will always show 0.
NOTE: Dead-band changes via
Object 34 are stored in nonvolatile
memory. Make sure to reissue the
Object 34 dead bands after a warm
(HIS C) or cold start (power cycle).
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