Digital Communication Protocols

Abstract

Preceding chapters have focused specifically at sensors, actuators, and controllers, components which are necessary to form a servo drive. In order to integrate these components to work as a system or to interconnect multiple control systems, signal communication protocols and standards will be necessary.

Currently, many servo drive components are equipped with a digital fieldbus interface. Fieldbus is a digital, bidirectional, serial bus communications network that links various instruments, transducers, controllers, final control elements, and other devices. It serves as a spinal column of distributed real time systems and tremendously simplifies the wiring among field devices.

In this chapter, the evolution of field communication protocols, along with the development in control and computer systems will be highlighted. The typical fieldbus protocol stack will be described, and the common field protocols currently used in servo drives will be presented, along with applications to servo drives.