6-9
RTU Mode
Node Address
01 H
Function
03H
Starting
Register
High
01H
Low
23H
Number of
Registers
High
00H
Low
01H
CRC-16
High
74H
Low
3CH
Node Address
01H
Function
03H
Data Length
02H
Data
High
17H
Low
70H
CRC-16
High
AFH
Low
82H
Node Address
02H
Function
83H
Exception code
52H
CRC-16
High
C0H
Low
CDH
Command Message
Response Message (Norm.)
Response Message (Error)
6.1.8 Loop Back Test [08H]
Check the communication between the master/client and the slave/server (AC Drive). The data used can be arbitrary.
ASCII Mode
3AH
STX
30H
Node Address
31H
30H
Function
38H
30H
Test Code
30H
30H
30H
41H
DATA
35H
33H
37H
?
LRC CHECK
?
0DH
END
0AH
3AH
STX
30H
Node Address
31H
30H
Function
38H
30H
Test Code
30H
30H
30H
41H
DATA
35H
33H
37H
?
LRC CHECK
?
0DH
END
0AH
3AH
STX
30H
Node Address
31H
38H
Function
38H
32H
Exception code
30H
?
LRC CHECK
?
0DH
END
0AH
Command Message
Response Message (Norm.)
Response Message (Error)
RTU Mode
Node Address
01 H
Function
08H
Test Code
High
00H
Low
00H
DATA
High
A5H
Low
37H
CRC-16
High
DAH
Low
8DH
Node Address
01H
Function
08H
Test Code
High
00H
Low
00H
DATA
High
A5H
Low
37H
CRC-16
High
DAH
Low
8DH
Node Address
01H
Function
88H
Exception code
20H
CRC-16
High
47H
Low
D8H
Command Message
Response Message (Norm.)
Response Message (Error)