The DCS (Distributed Control Systems) based micropracesadores emerged in the 70's, initially conceived as functional replacements electronic instrumentation panel. Initially used displays (display) panel discrete as with the implementation of the time. Earlier in the 70's, analog panels were used to perform all the tasks of remote monitoring of processes, the need for using available resources more efficiently and intelligently, however, were the main reasons to search for systems capable of improving the competitiveness of companies. The DCS, through its development within manufacturing companies advanced control systems, have become commercially viable to improve the accuracy, operability, computational and logical ability, stability in calibration, and ease of modification strategies Sas control.
EVOLUTION OF DCS
Distributed Control Systems (DCS) have been evolving since the mid 80's to be essentially replacement control panels to fully integrated networks for plant operations. This progress has been driven in part by the revolution in microprocessor technology and software and partly by economic necessity.
Central Control
Distributed Control
Comparison between centralized and distributed system
These systems evolved rapidly, adding workstations (workstations) based on video and shared control, capable of handling complex regulatory control strategies and sequential, containing information of functional elements such as PID controllers, totalizers, timers, logic circuits, computing devices , etc.
These systems evolved rapidly, adding workstations (workstations) based on video and shared control, capable of handling complex regulatory control strategies and sequential, containing information of functional elements such as PID controllers, totalizers, timers, logic circuits, computing devices , etc.
During those years, the personal computer industry with the advent of DOS as a standard led to the development of software packages increasingly higher quality and lower costs than rich (and still do today) the possibilities of the DCS, including:
- Managing relational database!
- Spreadsheet Packages
- Ability to statistical process control
- Expert systems
- Computer Process Simulation
- Computer Aided Design
- Desktop Utilities
- Management of object-oriented displays
- Workstations oriented Windows (windows)
- Information exchange with other plants
Figure - Schematic diagram of the architecture dei TDC 2000 Honeywell signature. The basic control you system used, which were the digital equivalent of conventional panel instruments.
In the late 80's and early 90's, the development of networked systems allowed for more cohesion between the software and communications, integrated systems standards:
- Open operating systems such as UNIX
- OSI Communications Model
- Client-server computing model
- Communication protocols between workstations (workstations)
- Management systems relational database! distributed
- Object Oriented Programming
- Software Engineering Computer Aided
ARCHITECTURE
The DCS is being transformed into distributed computing platforms with enough performance to support real-time applications in large scale to address applications escalabies small units. Open systems standards are enabling DCS i receive information from different sets of similarly compatible computing platforms, including businesses, laboratory information, maintenance and other plant systems, as well as giving information to these systems to support multiple applications.
The traditional DCS are organized into five major subsystems: operational workstations, control subsystems, data collection subsystems, subsystems and process computer networks.
We will see in the next article related subsystems DCS.
