Administrator Login And Commands Via Modbus For 8 Series Relays - GE Multilin 850 Communications Manual

CHAPTER 11: MODBUS PROTOCOL
8 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE

ADMINISTRATOR LOGIN AND COMMANDS VIA MODBUS FOR 8 SERIES RELAYS

Sending commands requires writing 4 bytes to the Command address register using the
Modbus Function 10H (Store Multiple Setpoints). The 4 bytes are the function and the
command values. The function value is always 05.
Table 11-19: Modbus Commands registers
Description
Command Register
Command Function Register
Table 11-20: Examples of Command values
Command Value
1
96
98
105
4096
A complete list of Modbus Commands is found at the end of chapter 11.
Function Format for "Clear All" command:
Table 11-21: Function Format for "Clear All" command
Slave # Function Data Starting
Address
FE 10 0080
Table 11-22: Function Format for "Clear Energy Use Data" command
Slave # Function Data Starting
Address
FE 10 0080
Table 11-23: Function Format for "Force Virtual Input 1" command
Slave # Function Data Starting
Address
FE 10 0080
Commands using Modbus Function 05H (Execute Operation)
Specific command operations such as described above can also be performed using
function code 05H.
Table 11-24: Format for Function Code 05H
Master Transmission
Slave Address
Function Code
Operation Code
Code Value
CRC
Table 11-25: Examples of Command values
Command Value
1
96
Memory Map Address
DEC
40129
40130
Value Description
Reset
Clear All Records
Clear Events
Clear Energy Use Data
Force Virtual Input 1
Number of Byte count
Setpoints
0002 04
Number of Byte count
Setpoints
0002 04
Number of Byte count
Setpoints
0002 04
Byte# Example
1 FE
1 05
2 00 01
2 FF 00
2 DF 6A
Value Description
Reset
Clear All Records
HEX
0x0080
0x0081
Data 1 Data 2
0005 0060
Data 1 Data 2
0005 0069
Data 1 Data 2
0005 1000
Description
message for slave # 254
execute operation
operation code
perform function
CRC error code
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