$_tmp = "alarm-data";
$xx = "@attributes";
if(isset($event->$_tmp))
{
	$obj = $event->$_tmp;
	print_r($obj);
	$xxx = (array)$obj->$xx;
	print_r($xxx);
}



SimpleXMLElement Object
(
    [@attributes] => Array
        (
            [reduction-key] => %uei%:%dpname%:%nodeid%:%interface%:%parm[#3]%
            [alarm-type] => 1
            [auto-clean] => true
        )

)
Array
(
)