scada: supervisory control and data acquisition

August 24, 2010 1 [email protected]

Process Dynamics and Control:

Department of

Chemical Engineering

University of Engineering

And Technology, Lahore

A.N.Tabish

2009-MS-Chem-25

SCADA: Supervisory Control And Data Acquisition

Presented to:

Dr. –Ing Naveed Ramzan

Presented by:

S. Zaheer Abbas

2009-MS-Chem-69

August 24, 2010 [email protected] 2

Contents:

1. Fundamentals of Control

2. Introduction of SCADA

3. Applications of SCADA

4. SCADA Architectures

5. Components of SCADA System

6. How SCADA System Works?

7. Comparison of SCADA, DCS, PLC and smart instrument

8. Security and Vulnerability of SCADA Systems

9. Conclusion


Fundamentals of Control:



Control Components:

1. Control Server

2. SCADA Server or Master Terminal Unit (MTU)

3. Remote Terminal Unit (RTU)

4. Programmable Logic Controller (PLC)

5. Intelligent Electronic Devices (IED)

6. Human-Machine Interface (HMI)

7. Data Historian

8. Input/Output (IO) Server



Control Components:

1. Fieldbus Network

2. Control Network

3. Communications Routers

4. Firewall

5. Modems

6. Remote Access Points



Analog control system block diagram

Analog Control


Discrete control system block diagram


Discrete Control:


• Acronym stands for Supervisory Control and Data Acquisition

• Not a full control system, but rather focuses on the supervisory level

• Purely software package that is positioned on top of hardware

• Combination of telemetry and data acquisition to which it is

interfaced, generally via (PLCs) or (DCS)

• Collecting of the information, transferring it back to the central site,

carrying out any necessary analysis and control and then displaying

that information on a number of operator screens or displays control

actions are then conveyed back to the process.

Introduction to SCADA:



Typical Schematic of Sensors to panel system


PC to PLC or DCS with fieldbus and sensor




PC to IED using a fieldbus



SCADA systems are designed to collect field information, transfer it to a central

computer facility, and display the information to the operator graphically or

textually, thereby allowing the operator to monitor or control an entire system

from a central location in real time.


All together, the term SCADA refers to the entire central system. The central

system usually monitors data from various sensors that are either in close

proximity or off site.



Applications of SCADA:

• Electric power generation, transmission and distribution:

• Water and sewage:

• Buildings, facilities and environments:

• Manufacturing:

• Mass transit:

• Traffic signals:


Three generations of SCADA systems:

1.First Generation – Monolithic

2.Second Generation – Distributed

3.Third Generation – Networked

SCADA Architecture:


Monolithic SCADA Systems:

SCADA Architecture:

First Generation of SCADA Architecture


Distributed SCADA Systems:

SCADA Architecture:

Second Generation of SCADA Architecture


Networked SCADA Systems:

SCADA Architecture:

Third Generation of SCADA Architecture


SCADA system involves essentially five levels or hierarchies:

1. Field level instrumentation and control devices

2. Marshalling terminals and RTUs

3. Communications system

4. The master station(s)

5. The commercial data processing department computer system

Components of SCADA System:

1. SCADA Hardware:


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SCADA may be classified as:

1.Propriety:

Companies develop proprietary software to communicate to their hardware.

2.Open:

They have high interoperability to mix different manufacturers’ equipment on

the same system.

2. SCADA Software:

Components of SCADA System:

• User interface

• Graphics displays

• Alarms

• Trends

• RTU (and PLC) interface

• Scalability

• Access to data

• Database

• Networking

• Fault tolerance and

redundancy

• Client/server

• distributed processing

Key features of SCADA software


How SCADA Works:

A SCADA system performs four functions:

1. Data acquisition

2. Networked data communication

3. Data presentation

4. Control

These functions are performed by four kinds of SCADA Components:

1. Sensors and control relays

2. Remote telemetry units (RTUs)

3. SCADA master units

4. Communications network


Comparison of SCADA, DCS, PLC & Smart Instrument :

SCADA System


Considerations and benefits of SCADA system:


• Overall control requirements

• Sequence logic

• Analog loop control

• Ratio and number of analog to digital points

• Speed of control and data acquisition

• Master/operator control stations

• Reliability/availability

• Speed of communications/update time/system scan rates

• System redundancy

• Expansion capability



Distributed Control System (DCS)



Programmable Logic Controller System (PLCs)


PLCs are used in

both SCADA and

DCS systems as the

control components

of an overall

hierarchical system

to provide local

management of

processes through

feedback control.




Smart Instrument


Obviously, a SCADA system’s initial cost has to be justified. A few typical reasons for implementing a SCADA system are:

• Improved operation of the plant or process resulting in

savings due to optimization of the system

• Increased productivity of the personnel

• Improved safety of the system due to better information and

improved control

• Improved energy savings due to optimization of the plant

• Improved and quicker receipt of data so that clients can be

invoiced more quickly and accurately



Security and Vulnerability of SCADA System:

Threats to SCADA Systems:

1. Criminal groups

2. Foreign intelligence services

3. Insiders

4. Phishers

5. Spammers

6. Spyware/malware authors


Industrial Security Incidents by Year




Potential Consequences of Security Incidents:

1. Physical Impacts.

2. Economic Impacts.

3. Social Impacts.



Relationship Between Corporate and SCADA Network:



Firewall between Corporate

Network and Control Network



Firewall and Router between

Corporate Network and

Control Network



Developing SCADA Security Strategies:

• Border Router and Firewalls

• Proxy Servers

• Operating Systems

• SCADA Firewalls

• SCADA Internal Network Design

• SCADA Server Operating Systems

• Firewall between Corporate Network and

Control Network


1. David Bailey and Edwin Wright (2003), “Practical SCADA for

Industry”, Elsevier. Inc

2. Ken Barnes, Briam Johnson and Reva Nickelson, “Review of

Supervisory Control and Data Acquisition (SCADA) Systems”

January 2004, Idaho National Engineering and Environmental

Laboratory.

3. M.Lakshmi Prasanna and A.Gayatri “A Technical Paper on ‘SCADA’ Technology” Sri Sai Institute of Technology.

4. Technical Information Bulletin 04-1 “Supervisory Control and Data

Acquisition (SCADA) Systems” October 2004, Communication

Technologies, Inc.

5. Technical Manual on ‘‘Spervisory Control and Data Acquisition

(SCADA) Systems for Command, Control, Communications,

Computer, Intelligence, Surveillance, and Reconnaissance (C4isr)

Facilities Headquarters”, Department of the Army, Washington, Dc,

January 2006

References:

http://www.powershow.com/view.php?id=2798057&t=Scada+\(Supervis+Control+and+Data+Acquisition\)

scada: supervisory control and data acquisition

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