Schweitzer Engineering Laboratories SEL-787 - Table H.5 User-Defined Digital Status Words Selected by the NUMDSW Setting; Table H.6 PM Trigger Reason Bits-IEEE C37.118 Assignments

H.8
SEL-787 Relay Instruction Manual Date Code 20081022
Synchrophasors
Settings for Synchrophasors
NUMDSW
Selects the number of user-definable digital status words to be included in the
synchrophasor data stream.
This setting is one of six settings that determine the minimum port SPEED
necessary to support the synchrophasor data packet rate and size—see
Communications Bandwidth on page H.12 for detailed information.
The choices for this setting depend on the synchrophasor system design. The
inclusion of binary data can help indicate breaker status or other operational
data to the synchrophasor processor.
➤ Setting NUMDSW := 0 sends no user-definable binary status
words.
➤ Setting NUMDSW := 1 sends the user-definable binary status
words, as listed in Table H.5.
TREA1, TREA2, TREA3, TREA4, and PMTRIG
Defines the programmable trigger bits as allowed by IEEE C37.118.
Each of the four Trigger Reason settings, TREA1–TREA4, and the PMU
Trigger setting, PMTRIG, are
SELOGIC control equations in the Global settings
class. The SEL-787 evaluates these equations and places the results in Relay
Word bits with the same names: TREA1–TREA4, and PMTRIG.
The trigger reason equations represent the Trigger Reason bits in the STAT
field of the data packet. After the trigger reason bits are set to convey a
message, the PMTRIG Equation should be asserted for a reasonable amount
of time, to allow the synchrophasor processor to read the TREA1–TREA4
fields.
The IEEE C37.118 standard defines the first eight of 16 binary combinations
of these trigger reason bits (bits 0–3). The remaining eight binary
combinations are available for user definition.
Table H.5 User-Defined Digital Status Words Selected by the NUMDSW
Setting
NUMDSW Setting Digital Status Words Sent
Total Number of Bytes
Used for Digital Values
0 None 0
1 [SV32, SV31. . . SV17] 2
Table H.6 PM Trigger Reason Bits—IEEE C37.118 Assignments (Sheet 1 of 2)
TREA4 TREA3 TREA2 TREA1
Hexadecimal Meaning
a
(bit 3) (bit 2) (bit 1) (bit 0)
0000 0x00Manual
0001 0x01Magnitude Low
0 0 1 0 0x02 Magnitude High
0 0 1 1 0x03 Phase Angle Diff.
0 1 0 0 0x04 Frequency High/Low
0 1 0 1 0x05 df/dt High
0 1 1 0 0x06 Reserved
0111 0x07Digital
NOTE: The PM Trigger function is
not associated with the SEL-787
Event Report Trigger ER, a SEL
OGIC
control equation in the Report
settings class.