CREATE_ID (FB)

FUNCTION_BLOCK CREATE_ID

This function block creates a temporary ID from the physical identification of a slot of a PROFIBUS DP-slave or subslot of a PROFINET IO Device which can be used with the Communication Function Blocks.

In contrast to the other address conversion functions, it does not retrieve the ID from the projected devices of the application, but creates a temporary assignment of ID and the given address.

Use case is for example a Profinet implicit read-service. (RDREC without established connection CNCT)

Note

Implementations may choose to only support a single or a limitted number of these temporary IDs and the underlying services.

Code-Example: Profinet implicit read

PROGRAM READ_Implicit
VAR
   addr : CommFB.ADDR_TYPE;
   createID : CommFB.CREATE_ID;

   execRead : BOOL;
   rdrec : CommFB.RDREC;
   buffer : ARRAY[0..63] OF BYTE;
END_VAR

// init address:
// (this data might be retrieved by a bus-scan)
addr.SYSTEM := CommFB.IO_SYSTEM_TYPE.PROFINET_IO;
addr.PN.D.STATIONNAME := 'pnDevice';      // 'pnDevice' is some online device
addr.PN.D.INSTANCE := 1;                  // typically 0 or 1

createID(ADDR := addr);
IF(createID.ENO AND execRead) THEN
   // Read data from profinet device
    rdrec.ID := createID.ID;            // ENO = TRUE, so the ID is valid and can be used for RDREC
   rdrec.INDEX := TO_INT(16#AFF0);     // I&M1-Data
   rdrec.MLEN := TO_INT(SIZEOF(buffer));
   rdrec.RECORD := ADR(buffer);
   rdrec(REQ := execRead);

   IF(rdrec.VALID OR rdrec.ERROR) THEN
       //execution done
       execRead := FALSE;
       rdrec(REQ := execRead);
   END_IF
END_IF

InOut:

Scope	Name	Type	Initial	Comment
Input	EN	BOOL	TRUE	Enable
Inout	ADDR	ADDR_TYPE		Data structure to define the address of a slot of a PROFIBUS DP-slave or a subslot of a PROFINET IO Device
Output	ENO	BOOL		Provided ID is valid.
	STATUS	DWORD		Last detected status, see enum ErrorCode
	ID	DWORD		Handle