Delta ASDA-B3 Series User Manual page 483

MODBUS Communication
Example 1: function code 03H, read multiple words
When the master issues a read command to the first slave:
9
The slave reads two continuous words starting from the start data address 0200H. In the
response message from the slave, the content of the start data address 0200H is 00B1H and
the content of the second data address 0201H is 1F40H. The maximum allowable number of
data in one single access is 10.
ASCII mode:
Command Message (Master):
Start
Slave Address
Function
Start Data Address
Data Number
(in words)
LRC
End 1
End 0
RTU mode:
Command Message (Master):
Slave Address
Function
Start Data Address
Data Number
(in words)
CRC (Check Low)
CRC (Check High)
Note: a silent interval of 10 ms is required before and after each transmission in RTU mode.
9-6
':'
'0'
'1'
'0'
'3'
'0'
'2'
'0'
'0'
'0'
'0'
'0'
'2'
'F'
'8'
(0DH) (CR)
(0AH) (LF)
01H
03H
02H (High)
00H (Low)
00H
02H
C5H (Low)
B3H (High)
Response Message (Slave):
Start
Slave Address
Function
Data Number
(in bytes)
Content of Start Data
Address 0200H
Content of the 2 nd Data
Address 0201H
LRC
End 1
End 0
Response Message (Slave):
Slave Address
Function
Data Number
(in bytes)
Content of Start Data
Address 0200H
Content of the 2 nd Data
Address 0201H
CRC (Check Low)
CRC (Check High)
ASDA-B3
':'
'0'
'1'
'0'
'3'
'0'
'4'
'0'
'0'
'B'
'1'
'1'
'F'
'4'
'0'
'E'
'8'
(0DH) (CR)
(0AH) (LF)
01H
03H
04H
00H (High)
B1H (Low)
1FH (High)
40H (Low)
A3H (Low)
D4H (High)