Delta Electronics ASDA-B Series User Manual
Page 244
Chapter 8 MODBUS Communications|ASDA-B Series
Revision January 2009
8-9
11-bit character frame (For 8-bit character)
8N2
Start
bit
0
1
2
3
4
5
6
Stop
bit
8-data bits
11-bits character frame
Stop
bit
7
8E1
Start
bit
0
1
2
3
4
5
6
Stop
bit
8-data bits
11-bits character frame
7
Even
parity
8O1
Start
bit
0
1
2
3
4
5
6
Stop
bit
8-data bits
11-bits character frame
7
Odd
parity
Communication Protocol:
ASCII Mode:
STX
Start character’: ’ (3AH)
ADR
Communication address: 1-byte consists of 2 ASCII codes
CMD
Command code: 1-byte consists of 2 ASCII codes
DATA(n-1)
…….
DATA(0)
Contents of data: n word = n x 2-byte consists of n x 4 ASCII codes, n
≤12
LRC
Command code: 1-byte consists of 2 ASCII codes
End 1
End code 1: (0DH)(CR)
End 0
End code 0: (0AH)(LF)
RTU Mode:
STX
A silent interval of more than 10ms
ADR
Communication address: 1-byte
CMD
Command code: 1-byte
DATA(n-1)
…….
DATA(0)
Contents of data: n word = n x 2-byte, n
≤12
CRC
Command code: 1-byte
End 1
A silent interval of more than 10ms