CONTROLLER FINAL CONTROL ELEMENT

MEASURINGMEANS

PROCESS

SET POINTSIGNAL

DEVIATIONSIGNAL

S.VP.V

OUTPUT SIGNAL

CORRECTIVE ACTION

M.VC

ON

TR

OL

LE

D V

AR

IAB

LE

SIG

NA

L

AUTOMATIC PROCESS CONTROL

AUTOMATIC PROCESS CONTROL

FLOW OUT

FIC

S.V.FLOW INDICATING CONTROLLE.

M.V

CONTROL VALVE

F.E (ORIFICE PLATE)

PIPE LINE

FLOW IN

P.V.

F.T.

AUTOMATIC FLOW CONTROL LOOP

Junction box

Marshalling rack

Barrier

Field transmitter

Junction box

Marshalling rack

Barrier

Control Valve

I / P

4 - 20 mA

4 - 20 mA 4 - 20 mA

4 - 20 mA 4 - 20 mA 4 - 20 mA

4 - 20 mA 4 - 20 mA

3 - 15 PSI

T

O

S

Y

S

T

E

M

4 - 20 mA

MODES OF OPERATION :

• MANUAL

• AUTO

• CASCADE

• SPC

• DDC

OPERATORSTATION

ENG. STATION

SUPERVISORYCOMPUTER

GATEWAY UNIT

CONTROLSTATION

DAS

GATEWAY UNIT

PLC

(OPTION)

(OPTION)

DATAHIGHWAY

MINIMUM CONFIGURATION OF DCS

RemoteProcessor-1

RemoteProcessor-2

RemoteProcessor-3

CRTCRT CRT CRT

Operator Station

SupervisoryComputer

Data Highway

I/O Wires I/O Wires I/O Wires

GEOGRAPHICALLY AND FUNCTIONALLY

DISTRIBUTED DIGITAL CONTROL SYSTEM

E

X

T

E

N

D

E

D

Controller-1 Controller-2 Controller-3

CRTCRT CRT CRT

Operator Station

SupervisoryComputer

Data Highway

I/O Wires I/O Wires I/O Wires

GEOGRAPHICALLY CENTRALISED FUNCTIONALLY DISTRIBUTED

DIGITAL CONTROL SYSTEM

DISTRIBUTED CONTROL SYSTEM

Controller Sub -System Operator Interface Supervisory Computer Data Highway

CONTROLLER DESIGN :

- Single Loop Programmable- Multi-Loop Programmable

- Multi Function- Function Block Concept- Programs using High Level Languages- Advanced Control Algorithms- Communication Interface

• Can talk to each other• Can talk to higher order systems

- Scan Time as high as 20 times / sec.

CONSOLE SUB-SYSTEM

MAN - MACHINE INTERFACE FOR THE TOTAL SYSTEM

DISPLAY HIERARCHY

1. OVERVIEW DISPLAY

2. AREA DISPLAY

3. GROUP DISPLAY

4. ALARM SUMMARY DISPLAY (PIONT DISPLAY)

MAN - MACHINE INTERFACE

• Intelligent , CRT based

• Operation by Exception

• Virtual Panels

• Faster Up-dates & Call-Ups

• Multi-Window

• Top- Down Approach

• Touch - Screens

• User - Definable Keys

• Voice Output

• Print Outs for

- Alarms

- Devices failure

-

ADVANTAGES OF DCS

• Tighter Control Reduces Off-Spec Products• Flexibility in Changing Control Strategy• Better Operator Interface

- Monitoring and Control by Exception- Colour Graphic Facility

• Reliability Through redundancy• Trend and Historical Record facility• MIS• Integrated Operation• Self - Diagnostics• Reduced Maintenance• Control Functions require no calibration

• Better Documentation due to self documentation option• Modularity ensures expandability• Can cope up with changing Technology: no obsolesce• Provides scope for advanced Controls and Optimization

MIS

Supervisory Computer

Supervisory Monitoring

Controllers

Process

HIERARCHY IN DCS

Cost ReportGeneration

Set-point Control Optimization

MAN-MACHINEINTERFACE

PROCESS :

Raw MaterialConversion

Product

ELEMENTS IN A PROCESS :

Feed Preparation Reaction Product Purification

VARIABLES :

Those Parameters which change with time and cause some variations in the Process itself.

• Flow• Temperature• Pressure• Level• Composition

What is a process

What are variables in a process

What are the effects of these variables on the process

How are these variables regulated.

What is a control system

What is digital control system

What is advanced control and Optimization

MEASUREMENT OF

PROCESS PARAMETERS

TRANSMISSION &

CONTROL

• Flow• Temperature• Pressure• Level• Composition

SAFETY• Flammable Materials in Industrial Processes

• Spillage may give rise to an Exp..ATM.

• Precautions to Protect both Plant and Personnel

• The ‘ HAZARDOUS’ and ‘ SAFE’ Areas classification

• What is IS ? (INTRINSIC SAFETY)

Restricting the Electrical Energy available in

Hazardous Area circuits such that any sparks or Hot

Surfaces that may occur as a Result of Electrical faults

are too weak to cause Ignition

•To Limit the Energy supplied to the Hazardous

areas we use Interface BARRIERS between the Safe

area and the Hazardous Area.

AREA CLASSIFICATION

IEC/CENELEC/EUROPE

STANDARD

NORTH AMERICA

PRESENT CONT.>1000HRS/ANNUM

INTERMITTENTLY>10<1000 HR/ANUUM

ABNORMALLY<10HR/ ANUUM

ZONE 0 ZONE1 ZONE 2

DIVISION 1 DIVISION 2

CURRENT LIMITORFUSE

INPUT

SUPPLYOUT PUT

TO XMITTER

Multiplexertransmitter

Multiplexerreceiver

Intrinsicallysafe

interface

N inputsHazardous area Safe area

Data Highway

N outputs

Hazardous area Safe area

X 16

MTL821transmitter

MTL825receiver

MTL3052Isolator

Data Highway

MTL switch multiplexer system

GUS 01

NIM 12

GUS 03 GUS 04 GUS 05 GUS 06 GUS 07 GUS 08 GUS 09

AM 25CG 22

GUS 02

NIM 11 HM 21 AM 26

LOCAL CONTROL NETWORK

The GUS is the primary TPS human interface. It provides a single window to the entire system, whether the data is resident in one of the LCN modules or in one of the devices in UCN or HIWAY.

Monitoring and manipulating continuous and discontinuous operations.

Annunciating and handling alarms

Displaying and printing trends, logs, journals, and reports

Monitoring and controlling system status and diagnostics.

Network configuration.

Building process database, custom graphics

Designing reports, Preparing control language programs.

Displaying and printing information required during troubleshooting

Diagnosing system problems

The HM is available with redundant drives , makes possible storage of, and quick access to large quantities of data.

History of process alarms, operator changes, operator messages, system status changes, system errors and system maintenance.

System files of all types, load images, and other data required anytime modules are reloaded or personalities are changed.

Checkpoint data for maintaining up to date device setting in the event a device is taken out of service.

Continuous process history to support logs and trends.

The computer gateway is a fully integrated node of TPS system , enabling it to exchange information with all other nodes on the same LCN

Its function is to serve as a communication link between the host computer and the LCN.

Its hardware components include an LCN interface, MCPU, memory, a power supply, and a Computer Network Interface.

The GC memory contains the standard TDC 3000 node environment software along with CG Specific application software and a user defined database.

The AM permits the implementation of certain complex control calculation and strategies that may not be practical or possible when using only process connected devices .

A set of standard advanced control algorithms is included, and custom algorithms and packages can be developed by using a process engineer oriented control language.

HPM 11 12 HPM 13 14 HPM 17 18 FSC 21 22HPM 15 16 FSC 23 24 FSC 25 26

UNIVERSAL CONTROL NETWORK

NIM

NIM

LCN

HPM’s dual 68040 platform offers a wide ranges of capabilities for present and future process requirements.

A toolbox of functions can be configured and programmed to meet the needs of data acquisition and advanced control requirement in a highly secure and performance intensive manner.

It offers flexible I/O functions for both data monitoring and control .

Control functions including regulatory, logic, and sequencing control are provided for continuous, batch, sequencing, and hybrid applications.

HPMs capabilities include peer to peer communications and compatibility with industrial standard communication protocols.

Junction box

Marshalling rack

Barrier

Field transmitter

Junction box

Marshalling rack

Barrier

Control Valve

I / P

4 - 20 mA

4 - 20 mA 4 - 20 mA

4 - 20 mA 4 - 20 mA 4 - 20 mA

4 - 20 mA 4 - 20 mA

3 - 15 PSI

T

O

S

Y

S

T

E

M

24 V DC 4 - 20 mA

MTLMUX

1372B

MTLMUX

1372B

TO SI CARD

CH 1

CH 2

CH 15

CH 16

H1

MTLMUX

1372B

MTLMUX

1372B

TO SI CARD

CH 1

CH 2

CH 15

CH 16

H1....

.

.

..

mV

1 0 0 1 1 0 0

1 0 0 1 1 0 0

1 0 0 1 1 0 0

1 0 0 1 1 0 01 / 0