This manual is designed to provide users with an understanding and appreciation of some of the theoretical concepts behind control system elements and operations, without the need of advanced math and theory. It also presents some of the practical details of how elements of a control system are designed and operated, such as would be gained from on-the-job experience. This middle ground of knowledge enables users to design the elements of a control system from a practical, working perspective, and comprehend how these elements affect overall system operation and tuning. This edition includes treatment of modern fieldbus approaches to networked and distributed control systems. Generally, this guidebook provides an introduction to process control, and covers analog and digital signal conditioning, thermal, mechanical and optical sensors, final control, discrete-state process control, controller principles, analog controllers, digital control and control loop characteristics. For those working in measurement and instrumentation and with control systems and PLCs.