ASDA-B2
Chapter 8 MODBUS Communications
Revision September 2013
8-11
RTU Mode:
Command message:
Response message:
Slave Address
01H
Slave Address
01H
Function 06H
Function 06H
Starting data
address
02H (Upper bytes)
Starting data
address
02H (Upper bytes)
00H (Lower bytes)
00H (Lower bytes)
Content of data
00H (Upper bytes)
Content of data
00H (Upper bytes)
64H (Lower bytes)
64H (Lower bytes)
CRC Check Low
89H (Lower bytes)
CRC Check Low
89H (Lower bytes)
CRC Check High
99H (Upper bytes)
CRC Check High
99H (Upper bytes)
Please note that a silent interval of more than 10ms is required before and after data
transmission in RTU mode.
Example 3
Function code: 10H, write N words (multiple words). The maximum value of N is 10.
For example, writing continuous 2 words, 0BB8H and 0000H from starting address 0112H
and address 0113H.
ASCII Mode:
Command message:
Response message:
Start ‘
:
’
Start ‘
:
’
Slave Address
‘0’
Slave Address
‘0’
‘1’
‘1’
Function
‘1’
Function
‘1’
‘0’
‘0’
Starting data
address
‘0’
Starting data
address
‘0’
‘1’
‘1'
‘1’
‘1’
‘2’
‘2’
Number of data
(In Word)
‘0’
Content of data
‘0’
‘0’
‘0’
‘0’
‘0’
‘2’
‘2’
Number of data
(In Byte)
‘0’
LRC Check
‘D’
‘4’
‘A’
Content of 1st data
‘0’
End 1
(0DH)(CR)
‘B’
End 0
(0AH)(LF)
‘B’
‘8’
Content of 2nd data
‘0’
‘0’
‘0’
‘0’
VARITEL INGENIERIA ELECTRONICA S.A.
[email protected] - www.varitel.com - Tel. (54) 11-4243-1171 / Fax: (54) 11-4292-7545
Manuel Baliña 456, Lomas de Zamora (B1832CCJ) Buenos Aires, Argentina.
