Question

There are two control approaches: PLCs, Distributed Control Systems (DCS).
Explain them and then answer the following question:
What are the reasons to choose one over the other?
Attention:
1)your answer at least one scientific paper source (i.e. it is NOT websites)
2)Only one page is required.

Answer 1

Programmable Logic Control Systems (PLC) are used to control individual machines. What it was making PLCs outstanding was its relatively simple operating system. The purpose of designing the same was to implement the tasks like scanning inputs and updating outputs. Because of its simple operating sructure it can execute programmes quickly. PLCs are generally more flexible and customizable in nature.  

Distribted Control Systems (DCS) are systems, which are used to control applications which are complex, large and geographically distributed industrial processes. It is a computerised control system, under which autonomous controllers are distributed through out the system. Distributed control systems are applied in most of the new generation products.

In Distributed control system installation cost is reduced, and its reliability is comparatively higher. It can be supervised with a remote monetaring system. This systems are largely used in certain manufactring areas, such as manufacturing processes which are continuous in nature, and are mostly batch oriented.  

Digital commnication between the distributed controllers, work stations and other computing elements is a primacry advantage of the Distribted control system.

Distribted control systems are becoming centralised at plant level, because of its ability to login to the remote equipment. It helps operators to control both enterprize and eqipment level, that also within and out side the plant.