Samwontech TEMI 2500 - Page 24

SAMWONTECH
1st Edition of TEMI2000_Series IM : Dec. 15. 2008 Page 22 / 58
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) -
◈
Example
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) -
◈
Example
Without any trouble, response message will be
- MODBUS ASCII :010800000002F5[cr][lf]
- MODBUS RTU 01080000000261CA