Question

The main function of a Distributed Control System (DCS) is to:

• A. Control a single loop only
• B. Provide centralized control of a plant
• C. Control processes in a distributed manner with central supervision
• D. Replace field instruments

Hint:

Logic Tip: Think of a DCS like an army. The general in the main tent (Central Supervision) doesn't fight every individual soldier's battle. He issues broad commands, and the local squad leaders on the battlefield (Distributed Control) figure out exactly how to execute them.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
A Distributed Control System (DCS) is a computerized control system for a process or plant usually with many control loops, in which autonomous controllers are distributed throughout the system.
Step 2: Key Formula or Approach:
The architecture is designed to reduce the risk of a single point of failure. If one controller fails, only a specific section of the plant is affected, while the rest continues to operate.
Step 3: Detailed Explanation:
In a DCS, control elements are not localized to a single central location (like an old-fashioned control board) but are distributed near the process sub-systems. However, these distributed controllers are linked to a central operator station where human supervisors can monitor and change setpoints for the entire plant. This provides the perfect balance of localized reliability and centralized supervision.
Step 4: Final Answer:
The function of a DCS is to control processes in a distributed manner with central supervision.