RDIAG (FB)

FUNCTION_BLOCK RDIAG

Read Diagnosis data from DP Slave.

This service is for Profibus only, Profinet uses a different, more advanced Diagnosis.

Code-Example: Profibus DP Diagnosis

PROGRAM PLC_PRG
VAR
    readDiag : CommfB.RDIAG;
    diag : CommFB.DP_DIAG;
    sMessage : STRING;
END_VAR

readDiag.REQ := TRUE;
readDiag.ID := CommFB.ID(EN := TRUE, Master := CIFX_PB.MasterID, SEGMENT := 0, STATION := 3, SLOT := 0);
readDiag.MLEN := TO_INT(SIZEOF(diag));
readDiag(DINFO := diag);
IF(readDiag.VALID) THEN
    IF(diag.status1.Diag.Station_Non_Existent) THEN
        sMessage := 'Station with Address = 3 is not available !';
    END_IF
END_IF

InOut:

Scope	Name	Type	Comment
Input	REQ	BOOL	Request
	ID	DWORD	Identifier of a of DP-slave (see: AddressConcept)
	MLEN	INT	maximum length to be read
Output	VALID	BOOL	New diagnosis data received and is valid
	BUSY	BOOL	FB is busy
	ERROR	BOOL	Error detected
	STATUS	DWORD	Last detected status
	LEN	INT	Length of diagnosis data
Inout	DINFO	DP_DIAG	Read diagnosis data (see: DP_DIAG