SCADA Seminar Report

SEMINAR REPORT

ON

SCADA

Submitted For Partial Fulfilment of Award Of

BACHELOR OF TECHNOLOGY

Degree

In

Electronics & Communication Engineering

Submitted to: Submitted by:

Mr. AMIT BINDAL ASHUTOSH KR. MAURYA

Assistant Professor ECE - 4th Year

ECE Department (0712831028)

BHARAT INSTITUTE OF TECHNOLOGY

BY-PASS ROAD, PARTAPUR

MEERUT ,U.P

NOVEMBER, 2010

1

2

ACKNOWLEDGEMENT

I would like to thank everyone who helped to see this seminar

to completion. In particular, I would like to thank my

ECE HOD Mr. P.K.RAGHUVANSHI for his moral support and

guidance to complete my seminar on time.

I express my gratitude to all my friends and classmates for their

support and help in this seminar.

Last but not the least I wish to express my gratitude to God

almighty for his abundant blessings without which this seminar

would not have been successful.

ASHUTOSH KUMAR MAURYA

ECE-4th year

0712831028

3

CONTENTS

Topic Page No.

Introduction 5

What is data acquisition? 6

Why or where we use SCADA? 7

Architecture 8

Communication 9

Interfacing 10

Database 11

SCADA as a system 12

Example of SCADA system 13

Human Machine Interface 14

Remote Terminal Unit 15

Central Root Computer 15

System Concept 15-16

Features of SCADA 17-18

Usefulness of SCADA 19-20

General terminology 21-23

Security Issues 24

What is Intouch 25

4

Key Benefits 26

Key Capabilities 26

SCADA as an asset 27

SCADA System Management 28

SCADA a boom in engineering 29

Practical uses of SCADA 29

Advantages of SCADA 30

SCADA Manufacturer 31

Conclusion 32

References 33

INTRODUCTION:

5

SCADA stands for Supervisory Control And Data Acquisition. SCADA refers to a system that collects data from various sensors at a factory, plant or in other remote locations and then sends this data to a central computer which then manages and controls the data. SCADA focuses on gathering and circulating the right amount of system information to the right person or computer within the right amount of time so that creative solutions are made possible.

The keyword supervisory indicates that decisions are not directly made by the

system. Instead, the system executes control decisions based on control

parameters entered by the agency staff. The system monitors the health of the

process and generates alarm notifications when conditions are out of tolerance.

It is also tasked with placing the process in a safe mode. It waits for user inputs

to correct problems. The supervisory mode is designed to operate the system in

a manner that avoids out of tolerance conditions. In a water / wastewater

process, pumps are started and stopped by the system according to limits

assigned by operations. As long as the system responds correctly to the control

commands, the system remains in control. It includes three processes.

● Industrial processes include those of manufacturing, production, power

generation, fabrication, and refining, and may run in continuous, batch,

repetitive, or discrete modes.

●Infrastructure processes may be public or private, and include water

treatment and distribution, wastewater collection and treatment, oil and gas

pipelines, electrical power transmission and distribution, civil defense siren

systems, and large communication systems.

●Facility processes occur both in public facilities and private ones,

including buildings, airports, ships, and space stations. They monitor and

control energy consumption.

WHAT IS DATA ACQUISITION?

6

Data acquisition is the process of retrieving control information from the

equipment which is out of order or may lead to some problem or when decisions

are need to be taken according to the situation in the equipment. So this

acquisition is done by continuous monitoring of the equipment to which it is

employed. The data accessed are then forwarded onto a telemetry system ready

for transfer to the different sites. They can be analog and digital information

gathered by sensors, such as flow meter, ammeter, etc. It can also be data to

control equipment such as actuators, relays, valves, motors, etc.

WHY OR WHERE WE USE SCADA?

7

SCADA can be used to monitor and control plant or equipment. The control

may be automatic, or initiated by operator commands. The data acquisition is

accomplished firstly by the RTU's (remote Terminal Units) scanning the field

inputs connected to the RTU (RTU’s may also be called a PLC - programmable

logic controller). This is usually at a fast rate. The central host will scan the

RTU's (usually at a slower rate.) The data is processed to detect alarm

conditions, and if an alarm is present, it will be displayed on special alarm lists.

Data can be of three main types. Analogue data (i.e. real numbers) will be

trended (i.e. placed in graphs). Digital data (on/off) may have alarms attached to

one state or the other. Pulse data (e.g. counting revolutions of a meter) is

normally accumulated or counted.

These systems are used not only in industrial processes. For example,

Manufacturing, steel making, power generation both in conventional, nuclear

and its distribution, chemistry, but also in some experimental facilities such as

laboratories research, testing and evaluation centers, nuclear fusion. The size of

such plants can range from as few as 10 to several 10 thousands input/output

(I/O) channels. However, SCADA systems evolve rapidly and are now

penetrating the market of plants with a number of I/O channels of several 100K.

The primary interface to the operator is a graphical display (mimic) usually via

a PC Screen which shows a representation of the plant or equipment in

graphical form. Live data is shown as graphical shapes (foreground) over a

static background. As the data changes in the field, the foreground is updated.

E.g. a valve may be shown as open or closed. Analog data can be shown either

as a number, or graphically. The system may have many such displays, and the

operator can select from the relevant ones at any time. SCADA systems were

first used in the 1960s.

ARCHITECTURE

8

In this section we are going to details which describe the common architecture

required for the SCADA products

Hardware Architecture

The basic hardware of the SCADA system is distinguished into two basic

layers: the "client layer" which caters for the man machine interaction and the

"data server layer" which handles most of the process data control activities.

The data servers communicate with devices in the field through process

controllers. Process controllers, e.g. PLC’s, are connected to the data servers

either directly or via networks or fieldbuses that are proprietary (e.g. Siemens

H1), or non-proprietary (e.g. Profibus). Data servers are connected to each other

and to client stations via an Ethernet LAN. Fig.1. shows typical hardware

architecture.

Figure 1: Typical Hardware Architecture

Communication

9

Internal Communication:

Server-client and server-server communication is in general on a publish-

subscribe and event-driven basis and uses a TCP/IP protocol, i.e., a client

application subscribes to a parameter which is owned by a particular server

application and only changes to that parameter are then communicated to the

client application.

Access to Devices:

The data servers poll the controllers at a user defined polling rate. The polling

rate may be different for different parameters. The controllers pass the requested

parameters to the data servers. Time stamping of the process parameters is

typically performed in the controllers and this time-stamp is taken over by the

data server. If the controller and communication protocol used support

unsolicited data transfer then the products will support this too.

A single data server can support multiple communications protocols; it can

generally support as many such protocols as it has slots for interface cards. The

effort required to develop new drivers is typically in the range of 2-6 weeks

depending on the complexity and similarity with existing drivers, and a driver

development tool kit is provided for this.

Interfacing

10

Application Interfaces / Openness

The provision of OPC client functionality for SCADA to access devices in an

open and standard manner is developing. There still seems to be a lack of

devices/controllers, which provide OPC server software, but this improves

rapidly as most of the producers of controllers are actively involved in the

development of this standard.

The products also provide

an Open Data Base Connectivity (ODBC) interface to the data in the

archive/logs, but not to the configuration database,

an ASCII import/export facility for configuration data,

a library of APIs supporting C, C++, and Visual Basic (VB) to access

data in the RTDB, logs and archive. The API often does not provide

access to the product's internal features such as alarm handling, reporting,

trending, etc.

The PC products provide support for the Microsoft standards such as Dynamic

Data Exchange (DDE) which allows e.g. to visualize data dynamically in an

EXCEL spreadsheet, Dynamic Link Library (DLL) and Object Linking and

Embedding (OLE).

Database

11

The configuration data are stored in a database that is logically centralized but

physically distributed and that is generally of a proprietary format. For

performance reasons, the RTDB resides in the memory of the servers and is also

of proprietary format. The archive and logging format is usually also proprietary

for performance reasons, but some products do support logging to a Relational

Data Base Management System (RDBMS) at a slower rate either directly or via

an ODBC interface.

Scalability

Scalability is understood as the possibility to extend the SCADA based control

system by adding more process variables, more specialized servers (e.g. for

alarm handling) or more clients. The products achieve scalability by having

multiple data servers connected to multiple controllers. Each data server has its

own configuration database and RTDB and is responsible for the handling of a

sub-set of the process variables (acquisition, alarm handling, archiving).

SCADA AS A SYSTEM

12

A SCADA System usually consists of the following subsystems:

A Human-Machine Interface or HMI is the apparatus which

presents process data to a human operator, and through this, the human

operator monitors and controls the process. A supervisory (computer)

system, gathering (acquiring) data on the process and sending commands

(control) to the process.

Remote Terminal Units (RTUs) connecting to sensors in the

process, converting sensor signals to digital data and sending digital data

to the supervisory system.

Programmable Logic Controller (PLCs) used as field devices

because they are more economical, versatile, flexible, and configurable

than special-purpose RTUs.

Communication infrastructure connecting the supervisory

system to the Remote Terminal Units.

A SCADA system could be programmed to:  

monitor high and low levels in the day tanks,

fill them when a certain level is reached,

calculated and store the volume used,

monitor the level in the main feed tank,

Alarm when a certain level is reached to notify purchasing (or send an e-

mail),

Plot the usage of chemicals vs time, process, or any other parameter.

13

TYPICAL SCADA SYSTEM

Example of scada system

14

HUMAN MACHINE INTERFACE

A HMI is the apparatus which presents process data to a human operator, and

through which the human operator controls the process.

HMI's are an easy way to standardize the facilitation of monitoring multiple

RTU's or PLC's (programmable logic controllers). Usually RTU's or PLC's will

run a pre programmed process, but monitoring each of them individually can be

difficult, usually because they are spread out over the system. Because RTU's

and PLC's historically had no standardized method to display or present data to

an operator, the SCADA system communicates with PLC's throughout the

system network and processes information that is easily disseminated by the

HMI.

HMI's can also be linked to a database, which can use data gathered from PLC's

or RTU's to provide graphs on trends, logistic info, schematics for a specific

sensor or machine or even make troubleshooting guides accessible.

REMOTE TERMINAL UNIT

The RTU connects to physical equipment. Typically, an RTU converts the

electrical signals from the equipment to digital values such as the open/closed

status from a switch or a valve, or measurements such as pressure, flow, voltage

or current. By converting and sending these electrical signals out to equipment

the RTU can control equipment, such as opening or closing a switch or a valve,

or setting the speed of a pump. The RTU can read digital status data or analogue

measurement data, and send out digital commands or analogue setpoints.

An important part of most SCADA implementation arealarms. An alarm is a

digital status point that has either the value NORMAL or ALARM.

15

CENTRAL CONTROL ROOM COMPUTER

The SCADA usually presents the information in the form of mimic. This means

that a operator can see a representation of the plant being controlled. For

example a picture of a pump connected to a pipe can show the operator that the

pump is running and how much fluid it is pumping through the pipe at the

moment. The operator can then switch the pump off. The SCADA will show the

flow rate of the fluid in the pipe decrease in relay time. The HMI package for

the SCADA system includes a drawing program that the operator or system

personnel use to change the way these points are represented in the interface.

These representation can be as simple as an on screen traffic light, which

represents the state of an actual traffic light in the field or as complex as a multi-

projector display representing the position of all the elevators in a skyscraper or

all the trains on a railway.

SYSTEM CONCEPT

The term SCADA usually refers to centralized systems which monitor and

control entire sites, or complexes of systems spread out over large areas

(anything between an industrial plant and a country). Most control actions are

performed automatically by remote terminal units ("RTUs") or by

programmable logic controllers ("PLCs"). Host control functions are usually

restricted to basic overriding or supervisory level intervention. For example, a

PLC may control the flow of cooling water through part of an industrial process,

but the SCADA system may allow operators to change the set points for the

flow and enable alarm conditions, such as loss of flow and high temperature, to

be displayed and recorded. The feedback control loop passes through the RTU

or PLC, while the SCADA system monitors the overall performance of the loop.

16

Data acquisition begins at the RTU or PLC level and includes meter readings

and equipment status reports that are communicated to SCADA as required.

Data is then compiled and formatted in such a way that a control room operator

using the HMI can make supervisory decisions to adjust or override normal

RTU (PLC) controls.

SCADA systems typically implement a distributed database, commonly referred

to as a tag database, which contains data elements called tags or points. A point

represents a single input or output value monitored or controlled by the system.

Points can be either "hard" or "soft". A hard point represents an actual input or

output within the system, while a soft point results from logic and math

operations applied to other points. (Most implementations conceptually remove

the distinction by making every property a "soft" point expression, which may,

in the simplest case, equal a single hard point.)

17

FEATURES OF SCADA

DYNAMIC PROCESS GRAPHIC mimics developed in SCADA

software should resemble the process mimic. SCADA should have good library

of symbols so that you can develop the mimic as per requirement. Once the

operator sees the screen he should know what is going on in the plant.

REAL TIME AND HISTORICAL TREND the trend play very

important role in the process operation. If your batch fails or the plant trips, you

can simply go to the historical trend data and do the analysis. You can have

better look of the parameters through the trend. Ex. We commission a SCADA

system for Acid Regeneration plant where the plant has to be operated on 850-

deg temperature. If the operator operates the plant at 900 deg you can imagine

how much additional LPG he is putting into the reactor. Again what will happen

to the bricks of the reactor? So the production manger’s first job will be to go

through the trends how the operators are operating the plant. Even when the

plant trips there are more than 25 probable reasons for the sample but if you go

through the history trends, it’s very easy to identify the problem.

ALARMS have a very critical role in automation. Generally you have alarm

states for each inputs/outputs like your temperature should not cross 80 deg or

lever should be less than 60. So if the parameters go in alarm state the operator

should be intimated with alarm. Most of the SCADA software support four

types of alarms like LOLO,LO,HI and HIHI. Deadband the value of deadband

defines the range after which a high low alarm condition returns to normal.

Alarms are the most important part of the plant control applications because the

operator must know instantly when something goes wrong. It is often equally

important to have a record of alarms and whether an alarm was acknowledged.

18

RECIPE MANAGEMENT is an additional feature. Some SCADA

software support it, some do not. Most of the plants are manufacturing multi

products. When you have different products to manufacture, you just have to

load the recipe of the particular product.

SECURITY is on facility people generally look for. You can allocate certain

facilities or features to the operator, process people, engineering dept and

maintenance dept. for example operators should only operate the system, he

should not be able change the application. The engineers should have access to

changing the application. The engineers should have access to changing the

application developed.

DEVICE CONNECTIVITY you will find there are hundreds of

automation hardware manufacturer like Modicon, Siemens, Allen Bradly, ABB.

Everybody has there own way of communication or we can say they have there

own communication protocol. SCADA software should have connectivity to the

different hardware used in automation. It should not happen that for Modicon I

am buying one software and for Siemens another one. The software like Aspic

or Wonderware has connectivity to almost all hardware used in automation.

DATABASE CONNECTIVITY now a days information plays very

important role in any business. Most manufacturing units go for Enterprise

Resource Planning or Management Information System.

19

USEFULNESS OF SCADA

Production Dept.

● Real time production status: manufacturing status is updated in real time in

direct communication to operator and control device

● Production schedules: production schedules can be viewed and updated

directly

● Production information management: production specific information is

distributed to all

Quality Dept.

● Data integrity and quality control is improved by using a common interface

● It is an open platform for statistical analysis

● Consolidation of manufacturing and lab data

Maintenance Dept.

● Improved troubleshooting and de-bugging: direct connection to wide variety

of devices, displays improves troubleshooting reduces diagnostic/debugging

time

● Plant can be viewed remotely. Notification can include pagers, e-mails and

phones.

● Co-ordination between maintenance and management reduces unscheduled

downtime.

20

Enterprise Information

● Corporate information and real time production data can be gathered and

viewed from anywhere within operations

● User specific information ensures better informed decisions

● Data exchange with standard databases and enterprise systems provides

integrated information solutions

Engineering Dept.

● Integrated automation solutions reduce design and configuration time

● Common configuration platform offers flexibility for constant configuration

in all areas

● Capable of connecting to wide variety of systems. Reduces start up time and

system training with industry proven open interfaces

Manufacturing Dept.

● Unscheduled down time is reduced due to swift alarm detection and event

driven information

● Makes operations easier and more repeatable with its real time functionality

● Secured real time operation are maintained with windows

21

GENERAL TERMINOLOGY

What is a Tag- a tag is a logical name for a variable in a device or local

memory (RAM). Tags that receive data from some external devices such as

programmable logic controllers or servers are refereed to as I/O tags. Tags that

receive data internally from software are called memory tags.

Analog Tags- store a range of values. EX temp, flow, density etc

Discrete tags- to store values such as 0 or 1. EX on/off status of a pump,

valves, switches etc.

System tags- store information generated while the software is running

including alarm info and system time and date.

String tags- are used to store ASCII strings a series of characters or whole

word. The max string length is 131 characters.

Touch links- allow the operator to input data into the system. EX. Operator

may turn the value on or off, enter a new alarm set point, run a complex logic

script etc.

Touch push buttons-are used to create object link that immediately

perform an operation when clicked with the mouse or touched. These operations

can be discrete value changes, action script executions and show or hide

window commands.

Colour links- are used to animate the line colour, fill colour or text colour of

an object. Each of these colour attributes can be made dynamic by defining a

colour link for the attribute.

22

Visibility- used to control visibility of an object based on the value of discrete

tag name or expression.

Blink- used to make an object blink based on the value of the discrete

tagname or expression.

Orientation- used to make an object rotate based on the value of a

tagname /expression.

Disable- used to disable the touch functionality of objects based on the value

of a tagname of expression. Often used as a part of a security strategy.

Value display links- provides the ability to use text object to display the

value of a discrete, analog or string tagname.

Percent fill links- used to provide ability to vary the fill level of a filled

shape according to the value of an analog tagname or an expression that

computes to an analog value.

Application script- are linked to entire applications and are used to start

other applications, create process simulation, calculate variables and so on:

three types of application scripts are on start up, while running, on shut down.

Window script- is linked to specific window. 3 types of window scripts are

on show, while showing, on hide.

Key script- touch pushbutton action scripts are similar to key scripts, except

they are associated with an object that you link to a touch link action

pushbutton. 3 types are on key down, while down, on key up.

23

Condition script- is linked to discrete tagname or expression that equates to

true or false. You can also use discrete expressions that contain analog

tagnames. 4 types of scripts that you can apply to a condition are on true, on

false, while true, while false.

Data change script- are linked to a tagname and/or tagname field changes

by a value greater than a dead band that you defined for the tagname in the

tagname dictionary.

Application security- to an application is optional. It provides the

application developer with the ability to control whether or not specific

operators are allowed to perform specific functions within an application

Security is based on the concept of operator logging on to the application and

entering his user name and password and access level. For each operator access

to any protected function is granted upon verification of his password and

access level.

SECURITY ISSUES

24

The move from proprietary technologies to more standardized and open

solutions together with the increased number of connections between SCADA

systems and office networks and the Internet has made them more vulnerable to

attacks.Consequently, the security of SCADA-based systems has come into

question as they are increasingly seen as extremely vulnerable to

cyberwarfare/cyberterrorism attacks.

In particular, security researchers are concerned about:

the lack of concern about security and authentication in the design,

deployment and operation of existing SCADA networks

the mistaken belief that SCADA systems have the benefit of security

through obscurity through the use of specialized protocols and proprietary

interfaces

the mistaken belief that SCADA networks are secure because they are

purportedly physically secured

the mistaken belief that SCADA networks are secure because they are

supposedly disconnected from the Internet

SCADA systems are used to control and monitor physical processes, examples

of which are transmission of electricity, transportation of gas and oil in

pipelines, water distribution, traffic lights, and other systems used as the basis

of modern society. The security of these SCADA systems is important because

compromise or destruction of these systems would impact multiple areas of

society far removed from the original compromise. For example, a blackout

caused by a compromised electrical SCADA system would cause financial

losses to all the customers that received electricity from that source. How

security will affect legacy SCADA and new deployments remains to be seen.

WHAT IS INTOUCH

25

Wonderware InTouch provides a single integrated view of all your controls and

information resources. Intouch enables engineers, supervisors, operators and

managers to view to view and interact with the working of entire operation

through graphical representations of their production processes.

THE INTOUCH ENVIOREMENT

InTouch consist of three major programs. The InTouch Application Manager,

Windowmaker and Windowviewer. InTouch also includes the diagnostics

program Window Logger.

The InTouch Application Manager organizes the application to

create. It is also used to configure Windowviewer as an NT service, to configure

Network Application Development for client based and server based

architectures, to configure Dynamic Resource Conversions and/or distributed

alarms.

WindowMaker is the development environment, where object oriented

graphics are used to create animated, touch sensitive display windows. These

display windows can be connected to industrial I/O systems and other Microsoft

Windows application.

WindowViewer is the runtime environment used to display graphic

windows created in WindowMaker. WindowViewer executes InTouch

QuickScript, performs historical data logging and reporting, processes alarm

logging and reporting and can function as a client and a server for both DDE

and Suite link communication protocol.

Key Benefits

26

Easy-to-use, easy to implement

Easy configuration, simplified maintenance

High security and availability

Virtually unlimited scalability

Key Capabilities

HMI visualization and geographically distributed SCADA

Template based development and maintenance

Remote application development and change management

Data level security built into the system

Easy and flexible alarm definition

Data collection and analysis for new and existing systems

Easy-to-use report generation

Open access to historical data

SCADA AS AN ASSET

27

TYPICAL DETERIORATION CURVE FOR INFRASTRUCTURE ASSET

SCADA SYSTEM MANAGEMENT

28

SCADA Systems Management (SSM) helps its customers to transform the

operational performance of their businesses through the use of Manufacturing

Enterprise Solutions (MES).

Our in-depth practical experience of a range of industries combines with our

expertise in the award-winning GE Fanuc Proficy products to enable us to

deliver insights that bring benefits.

SCADA A BOOM IN ENGINEERING

29

While one should rightly anticipate significant development and maintenance

savings by adopting SCADA product for the implementation of a control

system, it does not mean a “no effort” operation. The need for proper

engineering can not be sufficiently emphasized to reduce development effort

and to reach a system that complies with the requirements, that is economical in

development and maintenance and that is reliable and robust. Examples of

engineering activities specific to the use of a SCADA system are the definition

of:

● a library of objects complete with standard object behavior, graphical

interface and associated scripts for animation,

● templates for different types of “panels”, eg alarms

● instructions on how to control eg. A device

● a mechanism to prevent conflicting controls

PRACTICAL USES OF SCADA

● SCADA used as a control mechanism for chemical plants, electricity

generation, electric power transmission, electricity distribution, district heating.

● Control mechanisms are described in Process Control.

●EPICS is an example of an open source software environment used to develop

and implement SCADA system to operate devices such as particle accelerators,

telescopes and other large experiments.

ADVANTAGES OF SCADA SYSTEM

30

1. A SCADA system is "normally" significantly cheaper than a DCS.

2. SCADA can continue operating even when telecommunication are

temporarily lost.

3. SCADA systems allow a smaller number of operators to control a large

number of individual assets.

4. SCADA systems were designed to be used on large scale systems with

remote assets over a very large geographical area.

5. SCADA system improves operation, maintenance and customer service and

provides rapid response to emergencies.

6. It provides a high level of system reliability and availability.

SCADA MANUFACTURERS AND NAME OF

THE SOFTWARE

31

WONDERWARE Intouch

ALLEN BRADLEY R.S View

SIEMENS Wincc

MODICON Moriecon

G E FANUC Cimplicity

INTELLUSION I Fix

KPIT Ashtra

CONCLUSION

SCADA is a control system with

32

● More interfaces and efficient storage

● More record or device oriented configuration

● But system wide configuration tools are needed

● Are less expensive than DCS, but offer different functionality than DCS

● And finally various applications

REFERENCES

www.ref.web.cern.ch/ref/CERN/CNL/2002/003/scada/

33

www.princeton-indiana.com/wastewater/pages/scada/scada-overview.html

www.scadanews.com

www.sss-mag.com/scada.html

www.scada.com

34