Schweitzer Engineering Laboratories SEL-734, Instruction Manual

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E.2
SEL-734 Meter Instruction Manual Date Code 20090730
Distributed Network Protocol
Overview
SEL
OGIC
Counters
The binary counter indices 07–22 report SEL
OGIC
counter values
SC01–SC16.
Energy
Use binary counters for reporting energy values because they automatically
roll over at their full-scale values: 2
32
or 2
16
depending on variation. The
SEL-734 reports DNP energy counters in primary units affected by the
DECPLE setting and per-point scaling.
Load Profile
The SEL-734 reports load profile as the most recent record, or in fifty-record
groups when a DNP master writes the time and date of the earliest record
using analog outputs 40–45. After the DNP master writes to the date and time
analog output, the SEL-734 will update the DNP LDP points with the load
profile data. This update will take 5–30 seconds. Use one of the following
three methods to ensure that the SEL-734 has successfully updated the DNP
LDP points before the master reads the load profile data.
➤
Wait 30 seconds after writing the time and date
➤
Monitor the LDP Data Ready Binary Input flag and read after
the bit is set
➤
Monitor the LDP Data Ready Counter Input flag and read after
the bit is set
The SEL-734 reports DNP Load Profile counters (Object 20, Index 40–1008)
in secondary units scaled by 100. Load Profile counter information rolls over
at 9,999,999.99. SEL recommends using 32-bit counter information because
the 16-bit load profile counter information does not rollover in a predictable
manor.
The SEL-734P supports 12 independent load profile recorders: LDP1, LDP2,
LDP3, ... LDP12. Upon power-up, the SEL-734P defaults to and reports LDP1
recorder data. To retrieve LDP2 data, select and write a value of 1 to Analog
Output (Object 40, 41) point 39 before retrieving LDP data. Continue this
process for recorders 3–12 by writing a value of 2 for LDP3, 3 for LDP4, and
so forth. The SEL-734 returns a format error if the master writes a value
outside of the range 0–11. If the SEL-734 does not support the recorders
LDP2–LDP12, it will always report LDP1 regardless if the master writes a
0–11 to Analog Output (Object 40, 41) point 39.
VSSI
The SEL-734 reports VSSI as the most recent record or in 50-record groups
when a DNP master writes the time and date of the earliest record using
analog outputs 46–51. After the DNP master writes to the date and time
analog output, the SEL-734 will update the DNP VSSI points with the VSSI
data. This update will take 5–30 seconds. Use one of the following three
methods to ensure that the SEL-734 has successfully updated the DNP VSSI
points before the master reads the VSSI data.
➤
Wait 30 seconds after writing the time and date.
➤
Monitor the VSSI Data Ready Binary Input flag and read after
the bit is set.
Courtesy of NationalSwitchgear.com