Delta Electronics ASDA-B2 series User Manual page 276

ASDA-B2
RTU Mode:
Start
Slave address
Function
DATA(n-1)
.......
DATA(0)
CRC
End 1
RTU Mode: A silent interval of more than 10ms
RTU (Remote Terminal Unit) starts from a silent signal and ends at another silent signal.
There are communication address, function code, contents of data, CRC (Cyclical
Redundancy Check) between start and end characters.
DATA (Data Characters)
The format of data characters depends on the function code. The available command
codes and examples for AC servo drive are described as follows:
Example 1
Function code: 03H, read N words (multiple 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:
Start
Slave address
Function
Starting data
address
Number of data
LRC Check
End 1
End 0
Revision September 2013
info@varitel.com - www.varitel.com - Tel. (54) 11-4243-1171 / Fax: (54) 11-4292-7545
Manuel Baliña 456, Lomas de Zamora (B1832CCJ) Buenos Aires, Argentina.
VARITEL INGENIERIA ELECTRONICA S.A.
A silent interval of more than 10ms
Communication address: 1-byte
Function code: 1-byte
Contents of data: n word = n x 2-byte, n10
CRC check sum: 1-byte
A silent interval of more than 10ms
':'
'0'
'1'
'0'
'3'
'0'
'2'
'0'
'0'
'0'
'0'
'0'
'2'
'F'
'8'
(0DH)(CR)
(0AH)(LF)
Chapter 8 MODBUS Communications
Response message:
Start
Slave address
Function
Number of data
(In 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)
8-9