SAMWONTECH
1th Edition of TEMP1000_Series IM : Apr. 2014 Page 22 / 63
6.5 Function code - 08
Function code-08 is used to test loopback for self-diagnosis.
▣ Request Message Frame
Factor
ASCII
RTU
Protocol Header
:(Colon)
-
Slave Address
2 characters
8-Bit
Function code-08
2 characters
8-Bit
Diagnosis code Hi
2 characters
8-Bit
Diagnosis code Lo
2 characters
8-Bit
Data Hi
2 characters
8-Bit
Data Lo
2 characters
8-Bit
Error detecting
2 characters
16-Bit
Protocol Tail
2 characters (CR+LF)
-
◈ Exmaple
Request message to test loopback for self-diagnosis should be
- MODBUS ASCII
:010800000002F5[cr][lf]
- MODBUS RTU
01080000000261CA
▣ Response Message Frame
Factor
ASCII
RTU
Protocol Header
:(Colon)
-
Slave Address
2 characters
8-Bit
Function code-08
2 characters
8-Bit
Diagnosis code Hi
2 characters
8-Bit
Diagnosis code Lo
2 characters
8-Bit
Data Hi
2 characters
8-Bit
Data Lo
2 characters
8-Bit
Error detecting
2 characters
16-Bit
Protocol Tail
2 characters (CR+LF)
-
◈ Exmaple
Without any trouble, response message will be.
- MODBUS ASCII
:010800000002F5[cr][lf]
- MODBUS RTU
01080000000261CA
