EACON EC5000 Series, User Manual, Page: 54 / 72

EC5000
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MODBUS Communication Protocol
6
■ Command Code: 08H, Communication Loop Test
This command is used to test the communication status between the
controller device (usually PC or PLC) and drivers, and the drivers will send
The data content received back to the controller device without any operation.
1. ASCII Mode:
Inquiry Message Format: Response Message Format:
STX ‘:’
‘0’ ADR 1
ADR 0
‘1’
‘0’ CMD 1
CMD 0
‘8’
‘0’
‘0’
‘0’
Data
‘0’
‘1’
‘7’
‘7’
Data
‘0’
‘7’
LRC Check
‘0’
CR
END
LF
STX ‘:’
‘0’ ADR 1
ADR 0
‘1’
‘0’ CMD 1
CMD 0
‘8’
‘0’
‘0’
‘0’
Data
‘0’
‘1’
‘7’
‘7’
Data
‘0’
‘7’
LRC Check
‘0’
CR
END
LF
2.RTU Mode:
Inquiry Message Format: Response Message Format:
ADR 01H
CMD 08H
00H
Data
00H
17H
Data
70H
CRC CHK Low 8EH
CRC CHK High 0EH
ADR 01H
CMD 08H
00H
Data
00H
17H
Data
70H
CRC CHK Low 8EH
CRC CHK High 0EH
■
Function Code 06H: Write data to register
For example: as for Driver with Address 01H, write 6000(1770H) to the
internal setting parameter of driver 001DH
1.ASCII Mode:
Inquiry Message Format:
Response Message Format
2. RTU Mode:
Inquiry Message Format: Response Message Format:
Address 01H
Function 06H
00H
Data address
1DH
17H
Data content
70H
17H CRC CHK Low
CRC CHK High
D8H
STX ‘:’
‘0’
Address
‘1’
‘0’
Function
‘6’
‘0’
‘0’
‘1’
Data address
‘D’
‘1’
‘7’
‘7’
Data content
‘0’
‘9’
LRC Check
‘0’
CR
END
LF
STX ‘:’
‘0’
Address
‘1’
‘0’
Function
‘6’
‘0’
‘0’
‘1’
Data address
‘D’
‘1’
‘7’
‘7’
Data content
‘0’
‘9’
LRC C heck
‘0’
CR
END
LF
Address 01H
Function 06H
00H
Data address
1DH
17H
Data content
70H
17H CRC CHK Low
CRC CHK High
D8H
EC5000
MODBUS Communication Protocol