AioSetAoCallBackProc

Function

Registers the callback function that is called when the events relative to analog output raise.

Format

Ret = AioSetAoCallBackProc ( Id , CallBackProc , AoEvent , Param)

Parameters

Id [ VB.NET: Short ] [ C, C++ : short ] [ C# : short ] [ Python : ctypes.c_short ]
Specifies the ID retrieved from AioInit function.

CallBackProc [ VB.NET: IntPtr ] [ C, C++ : long * ] [ C# : IntPtr ] [ Python : ctypes.POINTER(ctypes.c_long) ]
Specifies the address of the callback function.

AoEvent [ VB.NET: Integer ] [ C, C++ : long ] [ C# : int ] [ Python : ctypes.c_long ]
Specifies the event factor from the following range in macro or value that calls the callback function.
AoEvent has the following meanings in bit, it can be specified by a combination of these bits.

The available event factor is based on whether the device buffer is used or whether the user buffer is used.

When "Event that the specified number of data are output" is used, set the number of generatings that raises the event by using AioSetAoEventSamplingTimes function.

Param [ VB.NET: IntPtr ] [ C, C++ : void * ] [ C# : void * ] [ Python : ctypes.c_void_p ]
Specifies the parameter address passed to the callback function.
If the parameter isn't necessary, specify NULL.

Return value

Ret [ VB.NET : Integer ] [ C, C++ : long ] [ C# : int ] [ Python : ctypes.c_long ]

Remarks

Registers the callback function using in this function, the callback function is called when any event raised in the device.
The operation of callback function is similar to event. Unlike event, callback does not need the windows handle, therefore the applications without windows can use callback.

This function cannot be used on devices without the analog output function.
If the device is in operation, the function cannot be performed.
It cannot be used with Window message notification (AioSetAoEvent).

When AioStopAo function is performed, the callback function isn't called.

You should not execute the functions that start/stop devices operation in the callback routine.

Example

Registers the callback function in "Event that device operation end" and "Event that the specified number of data are output" factor.

Callback Function

Format

Ret = CallBackProc ( Id , Message , wParam , lParam , Param )

Parameters

Id [ VB.NET: Short ] [ C, C++ : short ] [ C# : short ] [ Python : ctypes.c_short ]
The ID retrieved from AioInit is passed.

Message [ VB.NET: Short ] [ C, C++ : short ] [ C# : short ] [ Python : ctypes.c_short ]
The message ID is passed that cause the callback function to be called
Message ID is any of the following value.

wParam [ VB.NET: Integer ] [ C, C++ : WPARAM ] [ C# : int ] [ Python : ctypes.wintypes.WPARAM ]
The parameter is passed from the driver. It isn't used now.

lParam [ VB.NET: Integer ] [ C, C++ : LPARAM ] [ C# : int ] [ Python : ctypes.wintypes.LPARAM ]
The parameter peculiar to event is passed.

Param [ VB.NET: IntPtr ] [ C, C++ : void * ] [ C# : void * ] [ Python : ctypes.c_void_p ]
The parameter specified in the function AioSetAoCallBackProc is passed.
NULL is stored in this when NULL is specified in the parameter.