ASDA-B2 Chapter 8 Communications
Revision May, 2018 8-9
Example 1: function code 03H, access multiple words:
The Master issues the command to the 1
st
Slave and reads the continuous 2 words
starting from the start address 0200H. In response message from the Slave, the content of
starting address 0200H is 00B1H and the content of the 2
nd
data address 0201H is 1F40H.
The maximum allowable data in one single access is 10. The calculation of LRC and CRC
will be described in next chapter.
ASCII Mode:
Command message (Master): Response message (Slave):
Start ‘:’ Start ‘:’
Slave address
‘0’
Slave address
‘0’
‘1’ ‘1’
Function
‘0’
Function
‘0’
‘3’ ‘3’
Starting data
address
‘0’
Number of data
(In Byte)
‘0’
‘2’ ‘4'
‘0’
Contents of
starting data
address 0200H
‘0’
‘0’ ‘0’
Number of data
‘0’ ‘B’
‘0’ ‘1’
‘0’
Contents of
second data
address 0201H
‘1’
‘2’ ‘F’
LRC Check
‘F’ ‘4’
‘8’ ‘0’
End 1 (0DH)(CR)
LRC Check
‘E’
End 0 (0AH)(LF) ‘8’
End 1 (0DH)(CR)
End 0 (0AH)(LF)
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