GE Power Management
745 Transformer Management Relay
8-15
8 COMMUNICATIONS
8.2 MODBUS PROTOCOL
8
8.2.17 FUNCTION CODE SUBSTITUTIONS
Most 745 supported Modbus commands can be performed via function codes 03h (or 04h), and 10h and spe-
cial memory map addresses.
a) FUNCTION CODE 03H AND 04 SUBSTITUTIONS
Function codes 03h and 04h are interchangeable. Both have identical message formats, and both perform the
same action.
b) FUNCTION CODE 05H SUBSTITUTION
Function code 05h (EXECUTE OPERATION) can be performed by writing the command as if it were data in
the memory map.
0080h
OPERATION CODE
The message format and example is shown below.
Request slave device 11 to reset targets:
Master Query Message:
Example (hex):
SLAVE ADDRESS
11
query message for slave 11
FUNCTION CODE
10
store multiple setpoints (substituted for code 05H)
DATA STARTING ADDRESS: high order byte
00
data starting at address 0080
DATA STARTING ADDRESS: low order byte
80
NUMBER OF SETPOINTS: high order byte
00
1 register values = 2 bytes total
NUMBER OF SETPOINTS: low order byte
01
BYTE COUNT
02
2 bytes of data
DATA #1: high order byte
00
0001 = operation code 0001H (reset targets)
DATA #1: low order byte
01
CRC: low order byte
B5
CRC: high order byte
90
Field:
Example (hex):
SLAVE ADDRESS
11
response message from slave 11
FUNCTION CODE
10
store multiple setpoints
DATA STARTING ADDRESS: high order byte
00
data starting at address 0080
DATA STARTING ADDRESS: low order byte
80
NUMBER OF SETPOINTS: high order byte
00
1 setpoint values = 2 bytes total
NUMBER OF SETPOINTS: low order byte
01
CRC: low order byte
02
CRC: high order byte
31
Содержание 745 TRANSFORMER MANAGEMENT RELAY
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Страница 150: ...5 100 745 Transformer Management Relay GE Power Management 5 10 INVERSE VOLTS PER HERTZ CURVES 5 SETPOINTS 5 ...
Страница 210: ...7 36 745 Transformer Management Relay GE Power Management 7 2 BLOCK DIAGRAMS 7 SCHEME LOGIC 7 ...
Страница 322: ...9 12 745 Transformer Management Relay GE Power Management 9 3 USING 745PC 9 745 PC SOFTWARE 9 ...
Страница 392: ...11 24 745 Transformer Management Relay GE Power Management 11 1 COMMISSIONING SUMMARY 11 SETPOINT TABLES 11 ...
Страница 396: ...A 4 745 Transformer Management Relay GE Power Management A 1 FIGURES AND TABLES APPENDIXA A ...
Страница 398: ...B 2 745 Transformer Management Relay GE Power Management B 1 EU DECLARATION OF CONFORMITY APPENDIXB B ...
Страница 400: ...C 2 745 Transformer Management Relay GE Power Management C 1 WARRANTY INFORMATION APPENDIXC C ...
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Страница 407: ...GE Power Management 745 Transformer Management Relay NOTES ...