TECO L510S Series - Page 181

App 3-9
4.4 LOOP BACK testing [08H]
The function code checks communication between MASTER and SLAVE, the Instruction
message is returned as a response message without being changed, Any values can be
used for
test codes or data.
ASCII Mode
Instruction Message Response Message (Normal) Response(Fault)
3AH STX 3AH STX 3AH STX
30H
SLAVE
Address
30H
SLAVE
Address
30H
SLAVE
Address
31H 31H 31H
30H
Function
Code
30H
Function Code
38H
Function
Code
38H 38H 38H
30H
Test Code
30H
Test Code
32H
Error Code
30H 30H 30H
30H 30H 37H
LRC CHEC
30H 30H 35H
41H
DATA
41H
DATA
0DH
END
0AH
35H 35H
33H 33H
37H 37H
31H
LRC CHECK
31H
LRC CHECK
42H 42H
0DH
END
0DH
END
0AH 0AH
RTU Mode
Instruction Message Response Message (Normal) Response(Fault)
SLAVE Address 01H SLAVE Address 01H SLAVE Address 01H
Function Code 08H Function Code 08H Function Code 88H
Test Code
High
00H
Test Code
High
00H Error Code 20H
Low
00H
Low
00H
CRC-16
High
47H
DATA
High
A5H
DATA
High
A5H
Low
D8H
Low
37H
Low
37H
CRC-16
High
DAH
CRC-16
High
DAH
Low
8DH
Low
8DH