Distributed control system

摘要

A hierarchical distributive control system is disclosed. The lowest level of the system is a stand alone controller with hot plug in capability, which can accept either analog or digital signals, scale these signal with input subroutines, perform any one of a number of algorithms to produce control signals or can manually produce control signals and output these control signals as either analog or digital signals to field devices. A plurality of controllers communicates with an associated condenser over duel parallel digital communication buses with a full echo, verify communication routine. The condenser contains all records for all controllers under its supervision and can download control information into any replaced controller. A subhost is interconnected to a group of condensers and contains all records contained in all condensers under its supervision. All information can be uploaded from condensers to subhost or downloaded from subhost to condenser. In case of any failure in any subsystem, all lower level systems continue to operate. All controllers are interchangeable.