CHAPTER 11: MODBUS PROTOCOL ADMINISTRATOR LOGIN AND COMMANDS VIA MODBUS FOR 8 SERIES RELAYS
8 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE 11-11
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
Table 11-20: Examples of Command values
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
Table 11-22: Function Format for “Clear Energy Use Data” command
Table 11-23: Function Format for “Force Virtual Input 1” command
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
Table 11-25: Examples of Command values
Description Memory Map Address
DEC HEX
Command Register 40129 0x0080
Command Function Register 40130 0x0081
Command Value Value Description
1 Reset
96 Clear All Records
98 Clear Events
105 Clear Energy Use Data
4096 Force Virtual Input 1
Slave # Function Data Starting
Address
Number of
Setpoints
Byte count Data 1 Data 2
FE 10 0080 0002 04 0005 0060
Slave # Function Data Starting
Address
Number of
Setpoints
Byte count Data 1 Data 2
FE 10 0080 0002 04 0005 0069
Slave # Function Data Starting
Address
Number of
Setpoints
Byte count Data 1 Data 2
FE 10 0080 0002 04 0005 1000
Master Transmission Byte# Example Description
Slave Address 1 FE message for slave # 254
Function Code 1 05 execute operation
Operation Code 2 00 01 operation code
Code Value 2 FF 00 perform function
CRC 2 DF 6A CRC error code
Command Value Value Description
1 Reset
96 Clear All Records