RegisterCallback

Registers a function that the KINGSTAR Subsystem will call every cycle when new data comes in.

Syntax

KsError RegisterCallback(
     AppCallback callback,
     PVOID context
);

Parameters

callback: pointer to the callback function that will be called every cycle. See the AppCallback type.

context: pointer passed to the callback function if you need it.

Return value

If the function succeeds, it returns errNoError, otherwise an error code. For more information about the error code, see the KsError list.

Remarks

Registering a callback is optional. You can have your own cyclic thread in your application.
RegisterCallback can be used only in RT interface, because it is a real-time functionality. Calling it in other interfaces will get an errWrongEnvironment error.

Usable EtherCAT states

ecatOP

Example

Copy

/*
*    Assume that there is already a callback function in namespace userApp:
*    namespace userApp
*    {
*        int callBack(PVOID Context)
         {
*            return 0;
*        }
*    }
*
*    You can pass the function pointer as an argument:
*/
AppCallback callBack = userApp::callBack;
nRet = RegisterCallback(callBack, NULL);

/*
*    Or you can decay a lambda function to a function pointer (C++11):
*/
nRet = RegisterCallback([](PVOID Context){ return 0; }, NULL);

Requirements

	RT	Win32
Minimum supported version	4.0	4.0
Header	ksapi.h	ksapi.h
Library	KsApi_Rtss.lib	KsApi.lib