Industrial Engineer · phase 7 of 16

DCS

Distributed Control System that coordinates process control across networked controllers, operator stations, and engineering servers.

The Explain card

Plain English
A distributed control system spreads control across many networked controllers and treats the whole plant as one engineered system, with operator stations, engineering servers and the controllers all from one vendor working as a set.
Example
A refinery runs on a DCS. Thousands of loops are configured in one database, every operator screen looks the same, and a change to a loop is made once and appears everywhere.
Why it matters
A DCS is built for continuous processes with many analog loops where consistency and availability matter more than cost per point. PLCs are built for discrete machines, and although the two are converging, the mindset behind each is still different.
Hook
A plant that thinks of itself as one machine.

Word knowledge

How the word is built, where it came from, and what it sits beside in memory.

In a sentence

During commissioning, the engineer confirms that the 4-20 mA reactor-temperature signal reaches the correct DCS faceplate and activates the configured alarm.

Letter by letter
  • D Distributed identifies an architecture spread among multiple devices
  • C Control identifies the regulation and sequencing function
  • S System identifies the complete integrated arrangement
Where it came from
Origin
English control-engineering coinage formed from the initials of Distributed Control System
Entered the language
1970s
What changed
The label first distinguished emerging digital process-control architectures from centralized computer control, then broadened as networking and interoperability increased.
How it is spelled
Capitalisation
Written DCS in uppercase, including mid-sentence
Plural and possessive
The plural is DCSs, the singular possessive is DCS's, and the plural possessive is DCSs'.
Out loud
Spelled out letter by letter.

Same family

  • PLC
  • SCADA
  • SIS
  • HMI
Broken into chunks
  • D
    • distributed I/O
    • distributed architecture
  • C
    • control loop
    • control strategy
  • S
    • system architecture
    • system integration
What it sits beside

Same subject

  • process control
  • control loop
  • operator interface
  • alarm management

Same shape

industrial control platforms

three-letter control initialisms

Where it sits in the deck

Phase 7: PLC Related Automation Systems

The neighbours a PLC lives beside on a plant floor, from operator panels and SCADA up to the motion and batch systems it hands work to.

Neighbours in this phase