private static extern TwRC DSstatus([In, Out] TwIdentity origin, [In] TwIdentity dest, TwDG dg, TwDAT dat, TwMSG msg, [In, Out] TwStatus dsmstat);
private static extern TwRC DSMstatus([In, Out] TwIdentity origin, IntPtr zeroptr, TwDG dg, TwDAT dat, TwMSG msg, [In, Out] TwStatus dsmstat);