Industrial Automation

1.5 Control System Architecture

1.5 Control System Architecture3Industrial Automation

Principle

The control system has to suit the plant, not the reverse

The structure of the control system should reflects that of the plant

Ideally, each unit of the plant should have its own controller,

interacting with the controllers of the other, related units,

mirroring their physical interaction.

Example: Airbus: a wing is delivered with its own computers.

1.5 Control System Architecture5Industrial Automation

Example: Printing Architecture

1.5 Control System Architecture6Industrial Automation

Example: Production management system

transportation

cell control

manufacturing

cell control

scheduling maintenance quality control

plant network

floor network

production

planning

robot

controller

enterprise network

milling

machine

rail-guided

vehicle

cell

1.5 Control System Architecture7Industrial Automation

Example: Power plant control - 1980 (!)

Control systems look similar

1.5 Control System Architecture9Industrial Automation

Example: Rockwell (Allen-Bradley) NetLinx

Modular

I/O

HMI

24vdc

509 -BOD

Bridge or Linking Device

Programmable

Device

Support PC

Block I/O

Micro

PLC

Drive

Servo

Controller and Bridge

HMI

Desktop PC

with excel

Linking Device

Sensor

EtherNet / IP

ControlNet

DeviceNet

1.5 Control System Architecture10Industrial Automation

Example: Emerson's PlantWeb (Delta V)

1.5 Control System Architecture11Industrial Automation

Example: ABB Industrial IT (redundant system)

3rd party

controllers,

servers etc

Serial, OPC

or fieldbus

engineering

workplace

Field Bus

Firewall

Plant Network / Intranet

Field Bus

Client/server Network

3rd party

application

server

application

server

aspect

server

Workplaces

(clients)

Enterprise

Optimization

(clients)

Mobile

Operator

connectivity

server

Control Network

Programmable

Logic Controller

AC 800CRedundant

AC 800M

touch-screen

1.5 Control System Architecture15Industrial Automation

Centralized Control Architecture (classical)

Sensors, Actors

PLCsGroup

Control

Group

Control

Group

Control

Central Computer

(Mainframe)

Classical, hierarchical, centralized architecture.

The central computer only monitors and forwards commands to the PLCs

plant

1.5 Control System Architecture16Industrial Automation

plant

Decentralized Control System (DCS)

engineering

workstation

operator

workstationdata logger

controller controller controller controller

field bus

plant bus

all controllers can communicate as peers (without going through a central master),

restricted only by throughput and modularity considerations.

Note: Honeywell's "DCS™" stands for "Distributed Control System", it is not a decentralized control system, but

a control system for the process industry.

peer-to-peer (horizontal communication)hierarchical

(vertical

communication)