EC5000
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98
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99
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MODBUS Communication Protocol
6
1.ASCII Mode:
Inquiry Message Character String Format
Response Message Character String Format:
STX
‘: ’
‘0’
Address
‘1’
‘0’
Function
‘3’
‘0’
‘0’
‘1’
Starting address
‘D’
‘0’
‘0’
‘0’
Number of data
(count by word)
‘2’
‘D’
LRC Check
‘D’
CR
END
LF
STX
‘: ’
‘0’
Address
‘1’
‘0’
Function
‘3’
‘0’
Number of data
(count by byte)
‘4’
‘1’
‘7’
‘7’
Content of starting
Address 001DH
‘0’
‘0’
‘0’
‘0’
Content of address
001EH
‘0’
‘7’
LRC Check
‘1’
Response Message Format
:
2.RTU Mode:
Inquiry Message Format
:
r
Add ess
01H
Functi on
03H
00H
Content
of data
address
001DH
1DH
00H
Number of
data(count by word)
02H
CRC CHK Lo w
54H
CRC CHK High
0DH
Address
01H
Function
03H
Number of data
(count by byte)
04H
17H
Content of data
address
001DH
70H
00H
Content of data
address
001EH
00H
CRC CHK Low
FEH
CRC CHK High
5CH
6.2.2 Function Code (Function) and Data
Content (Data Characters)
03H: Read the register;
06H: Write data to the register;
08
H: Loop detection;
10H: Write several data in succession;
■
03H: Read several data to register
Function Code 03H: Read register (maximally, twenty continuous data can be
read at the same time)
For example: as for driver with Address 01H, two continuous data in register
can be represented as follows: Starting register Address 2102H
EC5000
MODBUS Communication Protocol
6.2.1 Communication Address (Address)
00H: Broadcast to all drivers;
01H: To driver with Address 01;
0FH: To driver with Address 15;
10H: To driver with Address 16, and so on, the maximal address can be
31(1EH).