Command Message; Response Message - Delta ASD-B2-0121-B User Manual

Chapter 8 MODBUS Communications
STX (Communication Start)
ASCII Mode: ':' character
RTU Mode: A silent interval of more than 10ms
ADR (Communication Address)
The valid communication addresses are in the range of 1 to 254.
For example, communication to AC servo drive with address 16 decimal:
ASCII Mode: ADR='1','0' => '1'=31H，'0'=30H
RTU Mode: ADR = 10H
CMD (Command Codes) and DATA (Data Characters)
The format of data characters depends on the command code. The available command codes
and examples for AC servo drive are described as follows:
Command code: 03H, read N words. The maximum value of N is 10.
For example, reading continuous 2 words from starting address 0200H of AC servo drive with
address 01H.
ASCII Mode:

Command message:

STX
ADR
CMD
Starting data
address
Number of data
LRC Check
End 1
End 0
8-10
':'
'0'
'1'
'0'
'3'
'0'
'2'
'0'
'0'
'0'
'0'
'0'
'2'
'F'
'8'
(0DH)(CR)
(0AH)(LF)

Response message:

STX
ADR
CMD
Number of data
(Count by byte)
Contents of
starting data
address 0200H
Contents of
second data
address 0201H
LRC Check
End 1
End 0
':'
'0'
'1'
'0'
'3'
'0'
'4'
'0'
'0'
'B'
'1'
'1'
'F'
'4'
'0'
'E'
'8'
(0DH)(CR)
(0AH)(LF)
Revision June 2010