MENU_CHANGE indicates that a new menu has been created, and as its name says, the menu has changed :
Example :
// Check for operator menu request
if ( BUTTON_GetState() == BUTTON_PUSHED )
{
BUTTON_WaitForRelease();
MENU_Set( (tMenu*) &myMenu );
return MENU_CHANGE;
}
MENU_REFRESH forces the system to redraw the current menu, by invoking the function MENU_Set.
Example : function "MsgVersion" in application.c.