Basically, Distributed Control Systems (DCS) is a control systems consist of:

  • Control modules: to compute the control algorithm, execute logical expression
  • IO modules: as interface to field devices, provide conversion from analog to digital and vice versa
  • Workstation: as human machine interface, server, historian, or provide software utilities to do engineering

All of these modules are communicate to each other via communication networks (ethernet, fieldbus, profibus, serial, etc).

Because of its distributed nature, DCS is very powerfull system to control a large petrochemical plant; the IO modules or control modules can be placed in a distributed area of the plant. The advance on communication systems also make it possible for DCS to be integrated to various type of dedicated 3rd party systems, such as PLCs.

In this post, I would like to present several types and basic architecture of DCS according to the manufacturer.

Foxboro I/A Series

The following figure is the basic architecture of Foxboro I/A Series system

I/A Series

Siemens PCS7

The following figure is the basic architecture of Siemens PCS7

Siemens PCS7

Honeywell Experion PKS

The following figure is the basic architecture of Honeywell Experion PKS

Honeywell Experion PKS

Honeywell TDC3000

The following figure is the basic architecture of Honeywell TDC3000

tdc30001

Honeywell Total Plant Solutions (TPS)

The following figure is the basic architecture of Honeywell TPS

tps

Yokogawa Centum CS3000

The following figure is the basic architecture of Yokogawa Centum CS3000

yoko1

to be continued …