IPGNCallbackHandler (ITF)

Epec Programming and Libraries Manual

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Supported platforms: CODESYS 3.5

IPGNCallbackHandler (ITF)

Description

This is the interface to PGN handling POU. The interface is used as a receive callback and has method HandlePGN.

HandlePGN method is executed each time when PGN is received if callback interface is defined.

Typically this is used by higher level libraries.

Limitations

This interface and it's methods are used only in CODESYS 3.5.

Method HandlePGN

Inputs

Input variable name	Data type	Description
i_pData	DWORD	Callback data pointer.

Example

The following example shows how to define callback to PGN and update data from the callback.

The following defines data struct which is given as data pointer to callback.

Data struct

TYPE Pgn_CallbackData :

STRUCT

pPGN_Data: POINTER TO J1939_PGN;

msgCount: BYTE;

END_STRUCT

END_TYPE

The following shows a callback POU.

Callback function block

FUNCTION_BLOCK PGNCallback IMPLEMENTS IPGNCallbackHandler

HandlePGN method

METHOD HandlePGN

VAR_INPUT

(* Callback data pointer *)

i_pData : DWORD;

END_VAR

VAR

pCallBackData: POINTER TO Pgn_CallbackData;

END_VAR

Code in HandlePGN

IF i_pData <> 0 THEN

pCallBackData := i_pData;

pCallBackData^.msgCount := pCallBackData^.msgCount + 1;

END_IF

The following initializes callback and callback data to PGN.

Definitions

VAR

PGNCallback: PGNCallback; // Callback instance

CallbackData: Pgn_CallbackData; // Callback data

END_VAR

Note: The definition of receive PGN is not shown in this example, the RxPGN variable can be replaced by the PGN struct from code template.

Init code

CallBackData.pPGN_Data := ADR(RxPGN);

CallBackData.MsgCount := 0;

RxPGN.itfCallback:=PGNCallback;

RxPGN.pCallbackData:=ADR(CallBackData);