# SNDEX_SetVolumeSwitchCallback

## Syntax

  `#include <twl/snd.h>`

      void SNDEX_SetVolumeSwitchCallback( SNDEXCallback callback, void* arg );

## Arguments

callback | `SNDEXCallback`-type function that will be notified when the volume button on the TWL console is pressed.
arg | Argument to pass to the function specified in callback.

## Description

Sets the callback function to be notified when the volume button on the TWL console is pressed.

Note that a PXI receive interrupt will send notification when the volume button is pressed, so callbacks will not occur if PXI receive interrupts are prohibited.

If other processing related to extended sound features is running when the volume button is pressed, the callback will not occur.

## Note

SNDEX functions cannot be used because exclusive control is used during callback execution. Returns `SNDEX_RESULT_EXCLUSIVE` even if called.

## See Also

`SNDEXCallback`

## Revision History

2008/10/10 Standardized terminology and added information about restrictions when a callback is executing.
2008/06/30 Initial version.

CONFIDENTIAL