Digital control technology@ microelectronics@ and digital data communication are rapidly evolving fields. Controversial issues such as geographical and functional distribution@ network topologies@ hierarchical architectures@ medium access control@ and the physical connection are not resolved. A single design standard to cover the scope outlined above is impractical. This guide@ therefore@ addresses alternate approaches to the task of applying a digital control system@ comparing relative advantages and disadvantages of these approaches@ and addresses criteria to be used to judge the suitability of commercially available systems for use in the power generation industry. IntroductionThis Application Guide is to be used as an aid for the user and system designer in the proper application of distributed digital control and monitoring systems for power generating plants. This guide is dedicated to establishing advanced requirements for distributed control and monitoring systems. Topics discussed can be applied to other industries as well@ but this document is addressed specifically to the requirements of the non-nuclear power generating plant. The special requirements for nuclear generating plants are beyond the scope of this document. The basic principles and control philosophy developed in this guide can apply to any kind of distributed digital control for non-nuclear power plants@ but only the specific control aspects of fossil-fuel power plants have been addressed (e.g.@ no details of hydroelectric power plants have been considered).