GE Multilin 745 Communications Manual page 81

CHAPTER 2: MODBUS PROTOCOL
745 TRANSFORMER PROTECTION SYSTEM – COMMUNICATIONS GUIDE
Value Bit arrangement
129 –––– 0000 1000 0001
130 –––– 0000 1000 0010
131 –––– 0000 1000 0011
132 –––– 0000 1000 0100
133 –––– 0000 1000 0101
134 –––– 0000 1000 0110
135 –––– 0000 1000 0111
136 –––– 0000 1000 1000
137 –––– 0000 1000 1001
138 –––– 0000 1000 1010
139 –––– 0000 1000 1011
140 –––– 0000 1000 1100
141 –––– 0000 1000 1101
142 –––– 0000 1000 1110
Example: 302Ah = 12230 decimal = 0011 0000 0010 1010 = Underfrequency 1 pickup,
since 0011 (first four bits) indicates a pickup event and 0000 0010 1010 (next 12 bits)
indicate an underfrequency 1 cause of event.
F25: Two's-complement signed value, 3 decimal places (16 bits)
Example: –1.234 stored as –1234
F26: Analog output range (16-bit enumeration)
Value Output range
0 0 to 1 mA
1 0 to 5 mA
2 4 to 20 mA
3 0 to 20 mA
4 0 to 10 mA
F27: Phase sequence (16-bit enumeration)
Value Output range
0 ABC sequence
1 ACB sequence
Cause of event
Unit not calibrated
EEPROM memory
Real time clock
Not used
Emulation software
Internal temperature
FlexLogic™ equation
DSP processor
Bad transformer settings
IRIG-B signal
Setpoint access denied
Aging factor limit
Ambient temperature
Tap changer failure
MODBUS PROTOCOL
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