Working of DCS systems

Working of Distributed Control System

Hameed Akhtar2k10-CHE-155

Working of DCSDCS is a control system which collects the data

from the field and decides what to do with them.  

Data from the field can be: 

- Stored for future reference- Used for simple process control- Use in conjunction with data from another part of the plant for advanced control strategies

Elements of Distributed Control System

Field Control station (FCS)It consists of input/output modules, CPU and communication

bus.

Operator station It isbasically human interface machine with monitor, the

operator man can view the process in the plant and check if any alarmis presents and he can change any setting, print reports..etc

Engineering station It is used to configure all input & output and drawing and

any things required to be monitored on Operator station monitor.

Components At first glance, the pictured system

architectures look components: Field devices� Input/output modules� Controllers� Human machine interface (HMI)� Engineering� Supervisory control� Business integration�

Levels of DCS Control

Advantages of DCS 1.

- Overall cost of the installation is lower 2.

- Interface with the process is improved3.

- More reliable 4.

- Flexible and relatively easy to expand5.

- Programming required to tailor the system can be done without knowing a high-level programming language

Vendors of DCS HoneywellFisher-RosemontBailyFoxboroYokogawaSiemen

UsesDCS is a very broad term used in a variety of industries, to

monitor and control distributed equipment.Electrical power grids and electrical generation plantsEnvironmental control systemsTraffic signalsRadio signalsWater management systemsOil refining plantsMetallurgical process plantsChemical plantsPharmaceutical manufacturingSensor networksDry cargo and bulk oil carrier ships

Disadvantages Increased software development cost More complex failure diagnosis and

dependence on communication technology. More Skills required By the OperatorsOverall Process is Dependent on DCS