SEMINAR ON

SCADA

SUBMITTED BY: DIKSHA VAID

ABSTRACT

Automation has been of high priority for the manufacturing sector, from

Ford's first set of Model-T Assembly lines in the early 1920s to the modern

factory floor. With appropriate automation, the aim was to rationalize the

production and keep the process under control. Instrumentation for

measuring process variables assumed a significant role in meeting such

goals. The development of new sensors and instruments took place in stages

concurrent with advancements in science and technology. This paper

comprehensively reviews the evolution of industrial automation. Essentially,

it reviews the milestones in the industrial automation and control systems,

the emergence of Distributed Control Systems (DCSs), the advanced control

architecture, the non-conventional technologies for the future and finally the

benefits from the networked system.

An industrial SCADA system will be used for the development of the

controls of LHC experiments. Here we describe the SCADA systems in

terms of their architecture, their interface to the process hardware, the

functionality and the application development facilities they provide. Some

attention is also aid to industrial standards to which they abide, their planned

evolution as well as the benefits of their use.

AUTOMATION – HISTORY

Ideas for ways of automating tasks have been in existence since the time of

the ancient Greeks. The Greek inventor Hero (fl. about A.D. 50), for

example, is credited with having developed an automated system that would

open a temple door when a priest lit a fire on the temple altar. The real

impetus for the development of automation came, however, during the

Industrial Revolution of the early eighteenth century. Many of the steam-

powered devices built by James Watt, Richard Trevithick, Richard

Arkwright, Thomas Savery, Thomas Newcomen, and their contemporaries

were simple examples of machines capable of taking over the work of

humans. One of the most elaborate examples of automated machinery

developed during this period was the drawloom designed by the French

inventor Basile Bouchon in 1725. The instructions for the operation of the

Bouchon loom were recorded on sheets of paper in the form of holes. The

needles that carried thread through the loom to make cloth were guided by

the presence or absence of those holes. The manual process of weaving a

pattern into a piece of cloth through the work of an individual was

transformed by the Bouchon process into an operation that could be

performed mindlessly by merely stepping on a pedal.

INTRODUCTION

a. what is automation

b. types of automation

c. role of computers in automation

a. What is Automation

Delegation of human control function to technical equipments

a. to increase production

b. to reduce cost

c. to reduce manpower

d. to improve safety working conditions

e. to reduce power consumption

f. to improve quality

b. Types of Automation

Automated machines can be subdivided into two large categories—open-

loop and closed-loop machines, which can then be subdivided into even

smaller categories. Open-loop machines are devices that, once started, go

through a cycle and then stop. A common example is the automatic

dishwashing machine. Once dishes are loaded into the machine and a button

pushed, the machine goes through a predetermined cycle of operations: pre-

rinse, wash, rinse, and dry, for example. A human operator may have

choices as to which sequence the machine should follow—heavy wash, light

wash, warm and cold, and so on—but each of these operations is alike in

that the machine simply does the task and then stops. Many of the most

familiar appliances in homes today operate on this basis. A microwave oven,

a coffee maker, and a CD player are examples.

Larger, more complex industrial operations also use open-cycle operations.

For example, in the production of a car, a single machine may be

programmed to place a side panel in place on the car and then weld it in a

dozen or more locations. Each of the steps involved in this process—from

placing the door properly to each of the different welds—takes place

according to instructions programmed into the machine.

Other category in which automation is divided is:

a. Scientific Automation

(used by scientists)

b. Industrial Automation

(building management system)

c. Office Automation

(used by non technical staff)

c. Role of computers in automation

Since the 1960s, the nature of automation has undergone dramatic changes

as a result of the availability of computers. For many years, automated

machines were limited by the amount of feedback data they could collect

and interpret. Thus, their operation was limited to a relatively small number

of alternatives. When an automated machine is placed under the control of a

computer, however, that disadvantage disappears. The computer can analyze

a vast number of sensory inputs from a system and decide which of many

responses it should make.

LAYOUT OF INDUSTRIAL AUTOMATION

AUTOMATION- APPLICATION

Manufacturing companies in virtually every industry are achieving rapid

increases in productivity by taking advantage of automation technologies.

When one thinks of automation in manufacturing, robots usually come to

mind. The automotive industry was the early adopter of robotics, using these

automated machines for material handling, processing operations, and

assembly and inspection. Donald A. Vincent, executive vice president,

Robotic Industries Association, predicts a greater use of robots for assembly,

paint systems, final trim, and parts transfer will be seen in the near future.

Vincent expects other industries to heavily invest in robotics as well.

Industries such as the electronics industry, with its need for mass

customization of electronic goods, the miniaturization of electronics goods

and their internal components, and the re-standardization of the

semiconductor industry, which, he says, will completely retool itself by

2004. Robotics will continue to expand into the food and beverage industry

where they will perform such tasks as packaging, palletizing, and filling; as

well as the aerospace, appliance, and non-manufacturing markets.

One can break down automation in production into basically three

categories: fixed automation, programmable automation, and flexible

automation. The automotive industry primarily uses fixed automation. Also

known as "hard automation," this refers to an automated production facility

in which the sequence of processing operations is fixed by the equipment

layout. A good example of this would be an automated production line

where a series of workstations are connected by a transfer system to move

parts between the stations. What starts as a piece of sheet metal in the

beginning of the process, becomes a car at the end.

Programmable automation is a form of automation for producing products in

batches. The products are made in batch quantities ranging from several

dozen to several thousand units at a time. For each new batch, the production

equipment must be reprogrammed and changed over to accommodate the

new product style.

Flexible automation is an extension of programmable automation. Here, the

variety of products is sufficiently limited so that the changeover of the

equipment can be done very quickly and automatically. The reprogramming

of the equipment in flexible automation is done off-line; that is, the

programming is accomplished at a computer terminal without using the

production equipment itself.

Computer numerical control (CNC) is a form of programmable automation

in which a machine is controlled by numbers (and other symbols) that have

been coded into a computer. The program is actuated from the computer's

memory. The machine tool industry was the first to use numerical control to

control the position of a cutting tool relative to the work part being

machined. The CNC part program represents the set of machining

instructions for the particular part, while the coded numbers in the

sequenced program specifies x-y-z coordinates in a Cartesian axis system,

defining the various positions of the cutting tool in relation to the work part.

AUTOMATION- ADVANTAGES

1. Replacing human operator in tedious task.

2. Replacing humans in tasks that should be done in dangerous environment.

3. Making tasks that are beyond human capabilities such as handle too heavy

loads, too large objects, too hot or cold substances or the requirement to

make things too fast or too slow.

4. Economy improvement- sometimes some kinds of automation imply improves in economy of enterprises, society or most of the humankind.

DISADVANTAGES

1. Technology limits- nowadays technology is not able to automatize all

desired task.

2. Initial costs are relative high.

SCADA- HISTORY

ON 20TH SEPT. 2000, the Finance Committee approved the proposal to

negotiate with ETM A.G. for the supply of PVSS-ETM’s SCADA

developing the control systems of ALICE, ATLAS, CMS and LHCb. In

accordance SCADA Working Group, that was set up by the CREN Controls

Board, re PVSS as one of the SCADA products for the development of

future control CREN.

These decisions are the accomplishment of around thirteen person- years

FTE- spanning over more than three years- to identify and evaluate a proper

control system that copies with the extreme requirements of high energy

particle experiments such as those of LHC.

Widely used in industry for Supervisory Control and Data Acquisition of

processes, SCADA systems are now also penetrating the experiments

laboratories for the controls of ancillary systems such as cooling, ventilation

distribution etc. More recently they were also applied for the controls of

small particle detectors such as the L3 muon detector and the NA48

experiment, to two examples as CREN.

SCADA systems have made substantial progress over the recent years in

functionality, scalability, performance and openness.

WHAT IS A SCADA?

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 generally refers to an industrial control system: a computer system

monitoring and controlling a process. The process can be industrial,

infrastructure or facility based as described below:

●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?

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 ?

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.SCADA systems have

made substantial progress over the recent years in terms of functionality,

scalability, performance and openness such that they are an alternative to in

house development even for very demanding and complex control systems

as those of physics experiments. SCADA systems used to run on DOS, VMS

and UNIX; in recent years all SCADA vendors have moved to NT and some

also to Linux.

ARCHITECTURE

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

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.

The products provide communication drivers for most of the common

PLCs and widely used field-buses, e.g., Modbus. Of the three fieldbuses that

are recommended are, both Profibus and Worldfip are supported but

CANbus often not. Some of the drivers are based on third party products

(e.g., Applicom cards) and therefore have additional cost associated with

them. VME on the other hand is generally not supported.

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

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

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

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

TYPICAL SCADA SYSTEM

EXAMPLE OF SCADA SYSTEM

SCADA (Supervisory Control and Data Acquisition) + HMI (Human

Machine Interface)

= CCC (Control, Cost reduction and Confidence)

CCC systems use real-time data acquisition and trending to allow you to see

what is happening with your business, as it happens. Any process can be

automated and monitored by these systems. Pioneered in the chemical and

petrochemical industries, new hardware and software now allow these

systems to be used for everyday processes. This results in cost savings that

pay for a system in a few months.

A quick example is the automation of a dosing system using day tanks and

large holding tanks used to fill the day tanks.

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.

HUMAN MACHINE INTERFACE

A Human-Machine Interface or 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.

An important part of most SCADA implementations are alarms. An alarm is

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

can be created in such a way that when their requirements are met, they are

activated. An example of an alarm is the "fuel tank empty" light in a car. The

SCADA operator's attention is drawn to the part of the system requiring

attention by the alarm. Emails and text messages are often sent along with an

alarm activation alerting managers along with the SCADA operator.

HARDWARE SOLUTIONS

SCADA solution often has Distributed Control Systems components. Use of

smart RTUs or PLCs, which are capable of autonomously executing simple

logic processes without involving the master computer, is increasing. A

functional block programming language, IEC 61131-3, is frequently used to

create programs which run on these RTUs and PLCs. Unlike a procedural

language such as the C programming language or FORTAN,IEC 61131-1

has minimal training requirements by virtue of resembling historic physical

control arrays. This allows SCADA system engineers to perform both design

and implementation of a program to be executed on a TRU or PLC.

System components

The three components of SCADA system are:

1. Multiple Remote Terminal Units

2. Central Control Room with Host Computer

3. Communication Infrastructure

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. Alarms

can be created in such a way that when their requirements are met, they are

activated. An example of an alarm is the “fuel tank empty” light in a car.

The SCADA operator’s attention is drawn to the part of the system requiring

attention by the alarm. Emails and the text messages are often sent along

with an alarm activation alerting managers along with the SCADA operator.

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. The interface is

usually 2D and is displayed using the X11 protocol, although some vendors

provide immersive 3D interfaces and support for other display APIs such as

Win 32 GDI/DirectDraw. Scada master computers typically run on top of a

third party operating system. Nearly all SCADA products run on either a

UNIX variant or HP Open VMS, although many vendors are beginning to

provide Microsoft Windows as a host operating system option. Initially

more ‘open’ platforms such as Linux were no as widely used due to highly

dynamic development environment and because a SCADA customer that

was able to afford the field hardware and devices to be controlled could

usually also purchase UNIX or open VMS licenses.

OPERATIONAL PHILOSOPHY

Instead of relying on operator intervention, or master station automation,

RTUs may now be required to operate on their own to control tunnel fires or

perform other safety related tasks. The master station software is required to

do more analysis of data before presenting it to operators including historical

analysis and analysis associated with particular industry requirements.

Safety requirements are now being applied to the systems as a whole and

even master station software must meet stringent safety standards for some

markets.

For some installations, the cost that would result from the control system

failing is extremely high possibly even lives could be lost. Hardware for

SCADA systems is generally ruggedized to withstand temperature, vibration

and voltage extremes but in these installations reliability is enhanced by

having redundant hardware and communications channels. A failing part can

be quickly identified and its functionality automatically taken over by

backup hardware. A filed part can often be replaced without interrupting

the process. The reliability of such systems can be calculated statistically

and is stated as the mean time to failure, which is a variant of mean time

between failures. The calculated mean time to failure of such high reliability

systems can be in the centuries.

COMMUNICATION INFRASTRUCTURE AND

METHODS

SCADA systems have traditionally used combinations of radio and direct

serial or modem connections to meet communication requirements, although

Ethernet and IP over SONET is also frequently used at large sites such as

railways and power stations.

This has also come under threat with some customer want in SCADA data to

travel over their pre-established corporate networks or to share the network

with other applications. The legacy of the early low bandwidth protocols

remains, though, SCADA protocols are designed to be very compact and

many are designed to send information to the master station only when the

master station polls the RTU.

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.

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.) Points are normally stored as value-timestamp pairs: a

value and the timestamp when it was recorded or calculated. A series of

value-timestamp pairs gives the history of that point. It's also common to

store additional metadata with tags, such as the path to a field device or PLC

register, design time comments, and alarm information.

FUNCTIONALITY

Access Control

Users are allocated to groups, which have defined read/write access

privileges to the process parameters in the system and often also to specific

product functionality.

MMI

The products support multiple screens, which can contain

combinations of synoptic diagrams and text. They also support the concept

of a "generic" graphical object with links to process variables. These objects

can be "dragged and dropped" from a library and included into a synoptic

diagram. Most of the SCADA products that were evaluated decompose the

process in "atomic" parameters (e.g. a power supply current, its maximum

value, its on/off status, etc.) to which a Tag-name is associated. The Tag-

names used to link graphical objects to devices can be edited as required.

The products include a library of standard graphical symbols, many of which

would however not be applicable to the type of applications encountered in

the experimental physics community. Standard windows editing facilities

are provided: zooming, re-sizing, scrolling... On-line configuration and

customization of the MMI is possible for users with the appropriate

privileges. Links can be created between display pages to navigate from one

view to another.

Trending

The products all provide trending facilities and one can summarize the

common capabilities as follows:

• the parameters to be trended in a specific chart can be predefined or

defined on-line

• a chart may contain more than 8 trended parameters or pens and an

unlimited number of charts can be displayed (restricted only by the

readability)

• real-time and historical trending are possible, although generally not

in the same chart

• historical trending is possible for any archived parameter

• zooming and scrolling functions are provided

• parameter values at the cursor position can be displayed

The trending feature is either provided as a separate module or as a

graphical object (ActiveX), which can then be embedded into a synoptic

display. XY and other statistical analysis plots are generally not provided.

Alarm Handling

Alarm handling is based on limit and status checking and performed

in the data servers. More complicated expressions (using arithmetic or

logical expressions) can be developed by creating derived parameters on

which status or limit checking is then performed. The alarms are logically

handled centrally, i.e., the information only exists in one place and all users

see the same status (e.g., the acknowledgement), and multiple alarm priority

levels (in general many more than 3 such levels) are supported.

It is generally possible to group alarms and to handle these as an

entity (typically filtering on group or acknowledgement of all alarms in a

group). Furthermore, it is possible to suppress alarms either individually or

as a complete group. The filtering of alarms seen on the alarm page or when

viewing the alarm log is also possible at least on priority, time and group.

However, relationships between alarms cannot generally be defined in a

straightforward manner. E-mails can be generated or predefined actions

automatically executed in response to alarm conditions.

Logging/Archiving

The terms logging and archiving are often used to describe the same

facility. However, logging can be thought of as medium-term storage of data

on disk, whereas archiving is long-term storage of data either on disk or on

another permanent storage medium. Logging is typically performed on a

cyclic basis, i.e., once a certain file size, time period or number of points is

reached the data is overwritten. Logging of data can be performed at a set

frequency, or only initiated if the value changes or when a specific

predefined event occurs. Logged data can be transferred to an archive once

the log is full. The logged data is time-stamped and can be filtered when

viewed by a user. The logging of user actions is in general performed

together with either a user ID or station ID. There is often also a VCR

facility to play back archived data.

Report Generation

One can produce reports using SQL type queries to the archive,

RTDB or logs. Although it is sometimes possible to embed EXCEL charts in

the report, a "cut and paste" capability is in general not provided. Facilities

exist to be able to automatically generate, print and archive reports.

Automation

The majority of the products allow actions to be automatically

triggered by events. A scripting language provided by the SCADA products

allows these actions to be defined. In general, one can load a particular

display, send an Email, run a user defined application or script and write to

the RTDB.

The concept of recipes is supported, whereby a particular system

configuration can be saved to a file and then re-loaded at a later date.

Sequencing is also supported whereby, as the name indicates, it is possible

to execute a more complex sequence of actions on one or more devices.

Sequences may also react to external events. Some of the products do

support an expert system but none has the concept of a Finite State Machine

(FSM).

EVOLUTION

SCADA vendors release one major version and one to two additional minor

versions once per year. These products evolve thus very rapidly so as to take

advantage of new market opportunities, to meet new requirements of their

customers and to take advantage of new technologies.

As was already mentioned, most of the SCADA products that were

evaluated decompose the process in "atomic" parameters to which a Tag-

name is associated. This is impractical in the case of very large processes

when very large sets of Tags need to be configured. As the industrial

applications are increasing in size, new SCADA versions are now being

designed to handle devices and even entire systems as full entities (classes)

that encapsulate all their specific attributes and functionality. In addition,

they will also support multi-team development.

As far as new technologies are concerned, the SCADA products are now

adopting:

• Web technology, ActiveX, Java, etc.

• OPC as a means for communicating internally between the client and

server modules. It should thus be possible to connect OPC compliant

third party modules to that SCADA product.

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. An alarm occurs when something goes wrong. It can signal

that a device or process has ceased operating within acceptable, predefined

limits or it can indicate breakdown, wear or process malfunction.

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.

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.

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

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. The colour attribute may be linked to the value

of a discrete expression, analogue expression, discrete alarm status or analog

alarm status.

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.

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

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.

There are two distinct threats to a modern SCADA system. First is the threat

of unauthorized access to the control software, whether it be human access

or changes induced intentionally or accidentally by virus infections and

other software threats residing on the control host machine. Second is the

threat of packet access to the network segments hosting SCADA devices. In

many cases, there is rudimentary or no security on the actual packet control

protocol, so anyone who can send packets to the SCADA device can control

it. In many cases SCADA users assume that a VPN is sufficient protection

and are unaware that physical access to SCADA-related network jacks and

switches provides the ability to totally bypass all security on the control

software and fully control those SCADA networks. These kinds of physical

access attacks bypass firewall and VPN security and are best addressed by

endpoint-to-endpoint authentication and authorization such as are commonly

provided in the non-SCADA world by in-device SSL or other cryptographic

techniques.

Many vendors of SCADA and control products have begun to address these

risks in a basic sense by developing lines of specialized industrial firewall

and VPN solutions for TCP/IP-based SCADA networks. Additionally,

application white listing solutions are being implemented because of their

ability to prevent malware and unauthorized application changes without the

performance impacts of traditional antivirus scans. Also, the ISA Security

Compliance Institute (ISCI) is emerging to formalize SCADA security

testing starting as soon as 2009. ISCI is conceptually similar to private

testing and certification that has been performed by vendors since 2007.

Eventually, standards being defined by ISA99 WG4 will supersede the

initial industry consortia efforts, but probably not before 2011.

The increased interest in SCADA vulnerabilities has resulted in vulnerability

researchers discovering vulnerabilities in commercial SCADA software and

more general offensive SCADA techniques presented to the general security

community. In electric and gas utility SCADA systems, the vulnerability of

the large installed base of wired and wireless serial communications links is

addressed in some cases by applying bump-in-the-wire devices that employ

authentication and Advanced Encryption Standard encryption rather than

replacing all existing nodes.

WHAT IS INTOUCH

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.

WONDERWARE SCADA SOFTWARE SOLUTIONS

SCADA solutions often impose complex demands on software architectures.

Wonderware InTouch HMI Visualization, coupled with the award-winning

ArchestrA-based Wonderware System Platform is uniquely positioned to

meet these challenges.

Solutions built on ArchestrA technology benefit from a single, open and

scalable software architecture that can connect to virtually any automation

system, remote terminal unit (RTU), intelligent electronic device (IED),

programmable logic controller (PLC), database, historian or business system

in use today. The open nature of this platform enables users to expand their

existing systems without having to buy new hardware or control systems.

Geographically dispersed applications, from a few hundred to one million

I/O and from a single node to hundreds of stations, can be rapidly and

securely implemented.

Key Benefits

• 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

TYPICAL DETERIORATION CURVE FOR INFRASTRUCTURE ASSET

SCADA SYSTEM MANAGEMENT

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.

We offer a range of cost-effective services that address the operational

management issues from shop floor to board room. Our pragmatic solutions

are targeted at unlocking value quickly

SCADA A BOOM IN ENGINEERING

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

PRAC TICAL 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

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 MANUFACTURER S AND NAME OF THE

SOFTWARE

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

● 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/

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

www.scadanews.com

www.sss-mag.com/scada.html

www.scada.com

COMPANY PROFILE

ABOUT PROLIFIC

Prolific Technology Inc., a leading IC design house and ASIC design service

provider, was founded in November 1997 by a group of highly experienced

and specialized technical engineers. The Company started out by developing

Smart I/O IC solutions, focusing on niche USB/IEEE 1394 bridge controller

products. The Company then also ventured in the Mixed-Mode technology

development, successfully designing Brushless Motor Driver IC and Hall

sensors. With the future towards 3C integration, the Company will devote

more efforts in SOC development as well as integration of competitive

multimedia (MPEG-4/JPEG/MP3) and GPS products. The Company will

also continue to introduce new technologies for existing IC product base that

will offer customers a wide range of product solutions. Through System

Integration technology, Prolific is envisioning herself to grow from a

Professional IC Design House to a leading SOC Core Technology Pioneer.

CONTENTS

AUTOMATION

• History

• Introduction

• Layout of Industrial Automation

• Applications

• Advantages and Disadvantages

SCADA

• History

• Introduction

• Architecture

• SCADA as a system

• Features of SCADA

• Usefulness of SCADA

• General terminology

• What is Intouch

• Intouch environment

• Wonderware SCADA solution

• SCADA a boom in engineering

• Practical uses of SCADA

• Advantages

• SCADA management

CONCLUSION

REFERENCES

INTRODUCTION

a. What is SCADA

b. What is Data

c. Why or where we use SCADA