7-12
08H : Diagnostic function
The sub-function code 0000H is able to check communication signal between Master
and Slaver. Data content is random value.
Ex: Use the diagnostic function for ID=01H
ASCII Mode
Query PC Æ Servo
Response Servo Æ PC (OK)
Servo Æ PC (ERROR)
STX ‘ : ’ STX ‘ : ’ STX ‘ : ’
‘ 0 ’ ‘ 0 ’ ‘ 0 ’
ADR
‘ 1 ’
ADR
‘ 1 ’
ADR
‘ 1 ’
‘ 0 ’ ‘ 0 ’ ‘ 8 ’
Function Code
‘ 8 ’
Function Code
‘ 8 ’
Function
Code
‘ 8 ’
‘ 0 ’ ‘ 0 ’ ‘ 0 ’
(HI)
‘ 0 ’
(HI)
‘ 0 ’
Exception
code
‘ 3 ’
‘ 0 ’ ‘ 0 ’ ‘ 7 ’
Sub-
Function
(Lo)
‘ 0 ’
Sub-
Function
(Lo)
‘ 0 ’
LRC
‘ 4 ’
‘ A ’ ‘ A ’ END1 (CR) (0DH)
‘ 5 ’ ‘ 5 ’ END0 (LF) (0AH)
‘ 3 ’ ‘ 3 ’
Data
(word)
‘ 7 ’
Data
(word)
‘ 7 ’
‘ 1 ’ ‘ 1 ’
LRC
‘ B ’
LRC
‘ B ’
END1 (CR) (0DH) END1 (CR) (0DH)
END0 (LF) (0AH) END0 (LF) (0AH)
RTU Mode
Query PC Æ Servo
Response Servo ÆPC (OK)
Servo Æ PC (ERROR)
ADR 01H
ADR 01H
ADR 01H
Function Code
08H
Function Code
08H
Function Code
88H
(HI) 00H
(HI) 00H
Exception
code
03H
Sub-
Function
(Lo) 00H
Sub-
Function
(Lo) 00H
CRC(Lo) 06H
A5H
A5H
CRC(Hi) 01H Data
(word)
37H
Data
(word)
37H
CRC(Lo) DAH
CRC(Lo) DAH
CRC(Hi) 8DH
CRC(Hi) 8DH