Exp	Description  The objective of the Control Display Unit  CDU  is to guide the inertial navigation system  INS  through motion sensors  accelerometers  and rotation sensors  gyroscopes  to continuously calculate the position  orientation and velocity of the moving object without the need of external references  Data  Read   Write  is passed between all the systems through communication systems  It Compromises of two different communications i e    RS  232   RS  422 