ABB TMD-T4 - Diagnostic Function; Function Code 08 Query;Response; Diagnostic Example

TMD-T4 protocol communication - instruction manual IM148-U-AB v0.92 pag. 7 / 12
DIAGNOSTIC (Function Code $ 08)
This function provides a test for checking the communication system.
Broadcast is not supported.
The instrument’s protocol has only the sub-function 0 of the diagnostics sub-functions set of the standard modbus
protocol.
The Query and the Response messages are the following:
QUERY:
START OF
FRAME
ADDRESS
FIELD
FUNCTION
CODE
SUB
FUNCTION
DATA
ERROR
CHECK
END OF
FRAME
START OF FRAME = Starting message marker.
ADDRESS FIELD = TMD device address (01...F7 HEX) (1 byte).
FUNCTION CODE = Operation code ( 08 HEX) (1 byte).
SUB FUNCTION = Sub-function 0 (00 00 hex) (2 byte).
DATA = Max 10 data bytes.
ERROR CHECK = Check sum.
END OF FRAME = End message marker.
RESPONSE:
The response must be the loopback of the same data.
START OF
FRAME
ADDRESS
FIELD
FUNCTION
CODE
SUB
FUNCTION
DATA
ERROR
CHECK
END OF
FRAME
START OF FRAME = Starting message marker.
ADDRESS FIELD = TMD device address (01...F7 HEX) (1 byte).
FUNCTION CODE = Operation code ( 08 HEX) (1 byte).
SUB FUNCTION = Sub-function 0 (00 00 hex) (2 byte).
DATA = Data bytes.
ERROR CHECK = Check sum.
END OF FRAME = End message marker.
DIAGNOSTIC EXAMPLE
QUERY RESPONSE
Field Name Example ( Hex) Field Name Example ( Hex)
Slave Address 01 Slave Address 01
Function Code 08 Function Code 08
Sub-function Hi 00 Sub-function Hi 00
Sub-function Lo 00 Sub-function Lo 00
Data Hi F1 Data Hi F1
Data Lo A7 Data Lo A7
Error Check (CRC) ?? Error Check (CRC) ??
?? ??