Chapter 9 Communications ASDA-A2
Revision February, 2017 9-11
Example 2: function code 06H, write single word:
The Master issues command to the 1
st
Slave and writes data 0064H to address 0200H. The Slave
sends the response message to the Master after the writing is completed. 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’
‘6’ ‘6’
Starting data
address
‘0’
Starting data
address
‘0’
‘2’ ‘2'
‘0’ ‘0’
‘0’ ‘0’
Data content
‘0’
Data content
‘0’
‘0’ ‘0’
‘6’ ‘6’
‘4’ ‘4’
LRC Check
‘9’
LRC Check
‘9’
‘3’ ‘3’
End 1 (0DH)(CR) End 1 (0DH)(CR)
End 0 (0AH)(LF) End 0 (0AH)(LF)
RTU Mode:
Command message (Master): Response message (Slave):
Address 01H Address 01H
Slave Function 06H Slave Function 06H
Starting data
address
02H (High)
Starting data
address
02H (High)
00H (Low) 00H (Low)
Data content
00H (High)
Data content
00H (High)
64H (Low) 64H (Low)
CRC Check Low 89H (Low) CRC Check Low 89H (Low)
CRC Check High 99H (High) CRC Check High 99H (High)
Please note: