distributed control system

What is a distributed control system?

If an operation or a plant uses a computerized control center containing many control loops, having a self-governing mechanism, it is known as a distributed control system (DCS). Whereas, there are no basic regulatory controls in such systems. Thus the system is a disparity to one which uses a centralized way for control.

Benefits of a distributed control system:

  • Uplifts reliability
  • Cutback installation amount
  • Localize control operation
  • Remote supervision and audit


Distributed control systems are emerging in high value and enormous scales. They are the source of attention because they lower the risks of design integration by providing a local control center as well as a centralized supervision station. Henceforth they are safety-critical procedure trade. That’s why these systems are widely applicable in such places that need high accuracy and security assurance.  For instance; process plants with continuous activities. But this does not restrain its application; they can also work in the orientation of batches. Major fields which are running their system specifically though distributed control system includes:

  1. Chemical and petrochemical refineries
  2. Environmental control systems
  3. Power plants (nuclear power plants)
  4. Agriculture and agrochemical plants
  5. Water treatment and management units
  6. Metals and metallurgical processes


The crux of the distributed control system is its reliability as it is divided and distributed among the different nodes of a processing unit. This eliminates the risks of a system crash. Only a certain portion of the plant processor will be affected by any loss in the system. This contrasts with a centrally supervised system which will result in a total failure of the whole plant processor in case of any problem.  Resultantly, quicker processing is ensured as the commands and controls are now localized.


A distributed control system encompasses different levels. Chiefly they all have their own functions and level of control.

  • Level 0 consists of sensors and valves
  • Level 1 consists of modules and electronic processors
  • Level 2 consists of supervisory controls

Level 3 consists of controls on productions and targets

Contemporary system:

Over the passage of time, various updates have been made in this system like all other systems of the world. The updated version of the system which we see today includes:

  • Wireless protocols
  • Remote transmission
  • Mobile control centers
  • Installed web servers


Most of the systems in the modern world today have shifted or are shifting towards a distributed control system. By virtue of modern techniques and tools, we are now able to control a plant from the micro as well as macro-level from within and outside the boundary of the plant. In fact, it will get more standardize in coming years with raising awareness.