This book is about the design of digital controllers. An attempt has been made to present digital control from scratch. The book is organized into five parts. The first deals with modelling, the second concerned with the topic of signal processing, the third devoted to identification of plants from measurements, fourth section looks at the transfer function approach to control design and the last section is devoted to state space techniques for control design. The topics of observers, Kalman filter and combined controller and observer have also been included.