This document provides an overview of a training report on programmable logic controllers (PLCs), supervisory control and data acquisition (SCADA) systems, and automation. It includes sections on the history and introduction of PLCs, the architecture of PLCs including the central processing unit and memory, programming PLCs using ladder logic, applications of PLCs and SCADA systems, the architecture of SCADA systems, and applications of automation in various industries. The training report was submitted to the Electrical Engineering department at the National Institute of Technology in Kurukshetra, India by a student as part of an internship on automation.

1. NATIONAL INSTITUTE OF TECHNOLOGY, KURUKSHETRA
A TRAINING REPORT
ON
PLC SCADA AND AUTOMATION
2017-18
Submitted To: Submitted By:
ElectricalEngineering AKSHAY SACHAN
Dept. Roll no. : 1140186
Section – E7

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INDEX
Serial No. Caption Page No.
1 Acknowledgement 3
2 Introduction to automation 4
3 PLC 6
4 Architecture of PLC 7
5 Ladder Diagram 9
6 Programming by Ladder Diagram 10
7 Application of PLC 20
8 SCADA 20
9 SCADA Software 21
10 Architecture 22
11 Application of SCADA 27
12 V.F.D. 28
13 Conclusion 31

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ACKNOWLEDGEMENT
I feel profound happiness in forwarding this industrial training report as an image of sincere
efforts. It is almost inevitable to ensure indebtedness to all who generously helped by sharing
their valuable experience & devoting their precious time with us, without whom this seminar
report would have never been accomplished.
First & foremost I extend my thanks & gratitude to the entire unit of “Technologics Global
Private Ltd, Bangalore”, whose guidance, teaching and invaluable suggestions provided me a
deep insight in my chosen field of technology, enhanced my knowledge and supported in
widening my outlook towards the communication industry. I am also very thankful to all the
engineers of the department for their kind support throughout the training.

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INTRODUCTION TO AUTOMATION
Automation is the use of control systems such as computers to control industrial machinery
and process, reducing the need for human intervention. In the scope of industrialization,
automation is a step beyond mechanization. Whereas mechanization provided human
operators with machinery to assist them with physical requirements of work, automation
greatly reduces the need for human sensory and mental requirements as well. Processes and
systems can also be automated.
Automation Impacts:
1. It increases productivity and reduce cost.
2. It gives emphasis on flexibility and convertibility of manufacturing process. Hence
gives manufacturers the ability to easily switch from manufacturing products.
3. Automation is now often applied primarily to increasequality in the manufacturing process,
where automation can increase quality substantially.
4. Increase the consistency of output.
5. Replacing humans in tasks done in dangerous environments.
Advantages of Automation:
1. Replacing human operators in tasks that involve hard physical or monotonous work.
2. Performing tasks that are beyond human capabilities of size, weight, endurance etc.
3. Economy improvement: Automation may improve in economy of enterprises, society or
most of humanity.
Disadvantages of Automation:
1. Technology limits: Current technology is unable to automate all the desired tasks.
2. Unpredictable development costs: The research and development cost of automating a
process may exceed the cost saved by the automation itself.
3. High initial cost: The automation of a new product or plant requires a huge initial
investment in comparison with the unit cost of the product.
Applications
 Automated video surveillance:
Automated video surveillance monitors people and vehicles in real time within a busy
environment. Existing automated surveillance systems are based on the environment
they are primarily designed to observe, i.e., indoor, outdoor or airborne, the amount

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of sensors that the automated system can handle and the mobility of sensor, i.e.,
stationary camera vs.mobile camera. The purpose of a surveillancesystemis to record
properties and trajectories of objects in a given area, generate warnings or notify
designated authority in case of occurrence of particular events.
 Automated manufacturing:
Automated manufacturing refers to the application of automation to produce things
in the factory way. Most of the advantages of the automation technology has its
influence in the manufacture processes.
The main advantages of automated manufacturing are higher consistency and quality,
reduced lead times,simplified production, reduced handling, improved work flow, and
increased worker morale when a good implementation of the automation is made.
 Home automation:
Home automation designates an emerging practice of increased automation of
household appliances and features in residential dwellings, particularly through
electronic means that allow for things impracticable, overly expensive or simply not
possible recent past decades.
 Industrial automation:
Industrial automation deals with the optimization of energy-efficient drive systems by
precise measurement and control technologies. Nowadays energy efficiency in
industrial processes are becoming more and more relevant. Semiconductor
companies like Infineon Technologies are offering 8-bit microcontroller applications
for example found in motor controls, general purpose pumps, fans, and e-bikes to
reduce energy consumption and thus increase efficiency.
Limitations to automation:
Current technology is unable to automate all the desired tasks.
As a process becomes increasingly automated, there is less and less labour to be saved or
quality improvement to be gained. This is an example of both diminishing returns and the
logistic function.
Similar to the above, as more and more processes become automated, there are fewer
remaining non-automated processes. This is an example of exhaustion of opportunities.

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PROGRAMMABLE LOGIC CONTROLLER
HISTORY OF PLC:
In the 1960's Programmable Logic Controllers were first developed to replace relays and relay
control systems.Relays,while very usefulin some applications,alsohave some problems. The
primary reason for designing such adevice was eliminating the largecost involved in replacing
the complicated relay based machine control systems for major U.S. car manufacturers. These
controllers eliminated the need of rewiring and adding additional hardware for every new
configuration of logic.These,along with other considerations, led to the development of PLCs.
plc was more improved in 1970’s. In 1973 the ability to communicate between PLCs was
added. This also made it possible to have the controlling circuit quite a ways away from the
machine it was controlling. However, at this time the lack of standardization in PLCs created
other problems. This was improved in the 1980's.The size of PLC was also reduced then, thus
using space even more efficiently. The 90's increased the collection of ways in which a PLC
could be programmed (block diagrams, instruction list, C, etc.).
INTRODUCTION OF PLC:
• A programmable logic controller (PLC) is an industrial computer control system that
continuously monitors the state of input devices and makes decisions based upon a
custom program to control the state of output devices.
• It is designedfor multiple inputs and output arrangements, extended temperature ranges,
immunity to electrical noise, and resistance to vibration and impact.
• They are used in many industries such as oil refineries, manufacturing lines, conveyor
systems and so on, wherever there is a need to control devices the PLC provides a flexible
way to "soft wire" the components together.
• The basic units have a CPU (a computer processor) that is dedicated to run one program
that monitors a series of different inputs and logically manipulates the outputs for the
desired control. They are meant to be very flexible in how they can be programmed while
also providing the advantages of high reliability (no program crashes or mechanical
failures), compact and economical over traditional control systems.

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In simple words, Programmable Logic Controllers are relay control systems put in a very small
package.This means that one PLC acts basicallylike a bunch of relays,counters, timers, places
for data storage, and a few various other things, all in one small package.
ARCHITECTURE OF PLC:
The PLC give output in order to switch things on or off. The PLC’s output is proportionally
activated according on the status of the system’s feedback sensors and input terminal which
is connected to PLC. The decision to activate output are based on logic programmes. The logic
programme stored in RAM or ROMmemory.
Fig : PLC internal architecture
The PLC also have same as computer, a CPU, data bus and address bus to communicate with
external devices such as programmers, display monitor The next diagram shows a simplified

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diagram of PLC’s structure. The central processing unit control everything according to a
programme stored in a memory (RAM/ROM).Everything is interconnected by two buses ,the
address bus and data bus .
Fig : Simplified PLC structure
Fig : Basic plc sections
Ladder Diagram (LD):
The Ladder Diagramis also a graphics oriented programming language which approaches the
structure of an electric circuit. Ladder Diagramconsists of a series of networks. Each network
consists on the left side of a series of contacts which pass on from left to right the condition
"ON" or "OFF" which correspond to the Boolean values TRUE and FALSE. To each contact
belongs a Boolean variable. If this variable is TRUE, then condition pass from left to right.
Fig : ladder diagram
Fig : ladder diagram
COMMUNICATION/PROGRAMMING WITH SOFTWARE RSLINX

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This chapter explains how to program the PLC. It describes how to write a program, how the
program is structured and representation of the programming language.
PROGRAMING BY LADDER DIAGRAM:
Ladder logic is a method of drawing electrical logic schematics. It is now a graphical language
very popular for programming Programmable Logic Controllers (PLCs). It was originally
invented to describe logic made from relays. The name is based on the observation that
programs in this languageresemble ladders, with two vertical "rails "and a series of horizontal
"rungs" between them. A program in the ladder logic, also called ladder diagram is similar to
a schematic for a set of relay circuits.
The Ladder Diagramis also a graphics oriented programming language which approaches the
structure of an electric circuit. The Ladder Diagramconsists of a series of networks. A network
is limited on the left and right sides by a left and right vertical current line. In the middle is a
circuit diagram made up of contacts, coils, and connecting lines.
Each network consists on the left side of a series of contacts which pass on from left to right
the condition "ON" or "OFF" which correspond to the Boolean values TRUE and FALSE. To
each contact belongs a Boolean variable. If this variable is TRUE, then the condition is passed
from left to right along the connecting line. Otherwise the right connection receives the value
OFF.
INPUT represented by : I OUTPUT
represented by: 0
Addressing method:
1 slot=32 bit=2 word (1 char./word=2 byte=16 bit)
Input addressing:
File letter: Slot number. Word number/Bit number
For example I:2.1/1 Output
addressing:
File letter: Slot number. Word number/Bit number
For example O:2.1/1
GENERALLY USED INSTRUCTIONS & SYMBOL FOR PLC PROGRAMMING:

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Input Instruction:
1) --[ ]-- This Instruction is Called XIC or Examine If Closed.
ie;If aNO switch is actuated then only this instruction will be true. Ifa NC switch is actuated
then this instruction will not be true and hence output will not be generated.
2) --[]-- This Instruction is Called XIO or Examine If Open
ie; If a NC switch is actuated then only this instruction will be true. If a NC switch is
actuated then this instruction will not be true and hence output will not be generated.
Output Instruction:
1. --( )-- This Instruction Shows the States of Output(called OTE). ie; If any instruction
either XIO or XIC is true then output will be high. Due to high output a 24 volt signal is
generated from PLC processor.
2. --(L)-- Output Latch (OTL)
OTL turns a bit on when the rung is executed, and this bit retains its state when the rung is
not executed or a power cycle occurs.
3. --(U)-- Output Unlatch(OTU)
OTU turns a bit off when the rung is executed, and this bit retains its state when the rung
is not executed or when power cycle occurs.
Rung:
Rung is a simple line on which instruction are placed and logics are created
E.g.; ---------------------------------------------
Timer:
Timer has three bit:
• EN: Enable bit :
The Timer Enable (EN) bit is set immediately when the rung goes true. It stays set until the
rung goes false.
• TT: Timer timing bit :
The Timer Timing (TT) bit is set when the rung goes true. It stays set until the rung goes
false or the Timer Done (DN) bit is set (i.e. when accumulated value equals preset value).

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 DN: Done bit:
The Timer Done (DN)bit is not setuntil the accumulated valueis equal to the preset value.
It stays set until the rung goes false.
Timer is three type:
1. TON 2. TOF 3. RTO
1. TON: Timer On
Counts time base intervals when the instruction is true.
Fig : Timer on
2. TOF: Timer off - Delay Counts time base intervals
when the instruction is false.
Fig : Timer off
3. RTO: Retentive Timer
This type of timer does NOT reset the accumulated time when the input condition goes
false. Rather, it keeps the last accumulated time in memory, and (if/when the input goes
true again) continues timing from that point.
Fig : Retentive Timer
Addressing of timer:

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Fig : Addressing of timer
Counter:
Counter has three bit:
• Count Up bit (CU):
Set When Rung conditions are true and remains set till rung conditions go false or a RES
instruction that has the same address as the CTD instruction is enabled.
• Done bit ( DN):
Set when the accumulated value is => the present value and remains set till the
accumulated value becomes less than the present value.
• Overflow ( OV):
continues counting from there and remains set tilla RES instruction that has same address
as the CTD instruction is executed or the count is incremented greater than or equal to
+32,767 with a CTU instruction.
Counter is two type:
1. CTU 2.
CTD
CTU: Count Up
Increments the accumulated value at each false-to true transition and retains the
accumulated value when the instruction goes false or when power cycle occurs.
Fig : Count Up
CTD: Count Down

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Decrements the accumulate valueat each false-totrue transition and retains the accumulated
value when the instruction goes false or when power cycle occurs.
Addressing of counter:
Fig: Addressing of timer
RESET: --(RES)--
Reset the accumulated value and status bits of a timer or counter.
A C5:0
-------[ ]---------------------(RES)-------------------------- When
A is true than counter C5:0 is reset.
BOOLEAN LOGIC DESIGN BY LADDER DIAGRAM:
1. AND logic:
Y0=X0.X1
Fig 3.5: AND logic ladder diagram
2. OR logic:
Y1=X0+X1

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Fig 3.6: OR logic ladder diagram
6. X-OR logic:
Y2=X0 + X1
3. NOT logic:
Y3=X0
Fig 3.7: NOT logic ladder diagram
4. NAND logic:
Y0= X0.X1
Fig : NAND logic ladder diagram
5. NOR logic:
Y1= X0+X1
Fig : NOR logic ladder diagram

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Fig : XOR logic ladder diagram
7. X-NOR logic:
Y2=X0 + X1
Fig : X-NOR logic ladder diagram
PROGRAMING AND OPERATIONS IN PLC:
To understanding the programming and operation we consider an example.
We have a car parking place which has five car parking capacity and we want to control the
parking gate/light. We have one input sensor, one exit sensor, for power supply start stop
push button, and for indication LED light
Making programme:
STEP: 1
Making start stop push button logic:
Fig: Push button logic ladder diagram
Here button A is start push button and B is stop push button and X is binary type output.
STEP: 2
Making input side sensor logic:

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Here we use one input sensor and one counter which is CTU (counter up) and take CTU preset
value 5.
STEP: 3
Making exit side sensor logic:
Fig : Output sensor logic ladder diagram
Here we use one Exit sensor and one counter which is CTD (counter down) and take CTD
preset value 5.
STEP: 4
Making parking light (LED) control logic:
Fig : led light logic ladder diagram
Here we take done bit (DN) of counter for controlling the LED light.
Operation:
After program making, it is download in plc. This program store in plc memory.

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When we push the start button than plc scan the input means input condition of button A is
true(1).so the binary output is also true(1).
Fig : operation of Push button logic(on pressing NO switch)
When button release than input condition of button a start is false. But the start button and
binary input both are in parallel. The address of binary output and binary input are same so
we get continuous supply.
Fig : operation of Push button logic (on releasing NO switch)
Binary output we can use as a input in next step ,its status is true for sense the entering car
we use a input sensor and for counting the car we use a CTU because accumulator value less
than preset value.
Similarly when fifth car enter than CTU count it’s accumulator value .Now counter done bit is
true because CTU address is C5:0 and take its preset value 5 because parking place capacity is
5. When first car enter then input sensor status goes true. Due to this CTU count one in its
accumulator value .but counter done bit does not true accumulator value equal to preset
value.

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Fig : operation of input sensor logic
When done bit goes true than LED output is true so parking light is on.
Fig : operation of led with input sensor logic
At exit side, one car is goes outside form parking place. Now four car is present in the parking
place but CTU done bit is on so LED light is on. To remove this interlocking problem we use
same address for both counter (CTU and CTD).
Both counter have same address so CTU accumulator value and CTD accumulator value both
are same.
Fig : operation of exit sensor logic
At exit side for sense the car we use a exit sensor .when one car is exit. Than exit sensor status
is true and CTD count and update the accumulator value.
Now both counter’s accumulator value less than preset value so done bit goes false and
parking light off .

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APPLICATIONS OF PLC:
1. The PLC can be programmed to function as an energy management system for boiler
control for maximum efficiency and safety.
2. In automation of blender recliners
3. In automation of bulk material handling system at ports.
4. In automation for a ship unloaded.
5. Automation for wagon loaders.
6. For blast furnace charging controls in steel plants.
7. In automation of brick molding press in refractory.
8. In automation for galvanizing unit.
9. For chemical plants process control automation.
10. In automation of a rock phosphate drying and grinding system.
11. Modernization of boiler and turbo generator set.
12. Process visualization for mining application.
13. Criteria display systemfor power station.

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SCADA
(SUPERVISORY CONTROL AND DATA ACQUISITION)
INTRODUCTION
SCADA stands for Supervisory Control and Data Acquisition. As the name indicates, it is not a
full control system, but rather focuses on the supervisory level. As such, it is a purely software
package that is positioned on top of hardware to which it is interfaced, in general via
Programmable Logic Controllers (PLCs), or other commercial hardware modules.
SCADA systems are used to monitor and control a plant or equipment in
Industries such as telecommunications, water and waste control, energy, oil and gas refining
and transportation. These systems encompass the transfer of data between a SCADA central
host computer and a number of Remote Terminal Units (RTUs) and/or Programmable Logic
Controllers (PLCs), and the central host and the operator terminals. A SCADA system gathers
information (such as where a leak on a pipeline has occurred), transfers the information back
to a central site, then alerts the home station that a leak has occurred, carrying out necessary
analysis and control, such as determining if the leak is critical, and displaying the information
in a logical and organized fashion.
SCADA systems consist of:
1. One or more field data interface devices, usually RTUs, or PLCs, which interface to field
sensing devices and local control switchboxes and valve actuators
2. A communications system used to transfer data between field data interface devices and
control units and the computers in the SCADA central host. The system can be radio,
telephone, cable, satellite, etc., or any combination of these.
3. A central host computer server or servers (sometimes called a SCADA Center, master
station, or Master Terminal Unit (MTU)
4. A collection of standard and/or custom software [sometimes called Human Machine
Interface (HMI) software or Man Machine Interface (MMI) software] systems used to

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provide the SCADA central host and operator terminal application, support the
communications system, and monitor and control remotely located field data interface
devices.
Fig : Typical SCADA System
ARCHITECTURE:
Generally SCADA systemis a centralized system which monitors and controls entire area. It is
purely software package that is positioned on top of hardware. A supervisory systemgathers
data on the process and sends the commands control to the process. For example, in the
thermal power plant the water flow can be set to specificvalueor it can be changed according
to the requirement. The SCADA systemallows operators to change the set point for the flow,
and enable alarm conditions in case of loss of flow and high temperature and the condition is

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displayed and recorded. The SCADA systemmonitors the overall performance of the loop. The
SCADA systemis acentralized systemto communicate with both wire and wireless technology
to Clint devices. The SCADA systemcontrols can run completely all kinds of industrial process.
EX: If too much pressure in building up in a gas pipe line the SCADA system can automatically
open a release valve.
Hardware Architecture:
The generally SCADA system can be classified into two parts:
• Clint layer
• Data server layer
The Clint layer which caters for the man machine interaction. The data server layer which
handles most of the process data activities. The SCADA station refers to the servers and it is
composed of a single PC. The data servers communicate with devices in the field through
process controllers like PLCs or RTUs. The PLCs are connected to the data servers either
directly or via networks or buses. The SCADA system utilizes a WAN and LAN networks, the
WAN and LAN consists of internet protocols used for communication between the master
station and devices.The physical equipment’s likesensors connected to the PLCs or RTUs.The
RTUs convert the sensor signals to digital data and sends digital data to master unit.
Fig 5.5: Hardware Architecture
Software Architecture:
Most of the servers are used for multitasking and real time database. The servers are
responsible for data gathering and handling. The SCADA system consists of a software
program to provide trending, diagnostic data, and manage information such as scheduled
maintenance procedure, logistic information, detailed schematics for a particular sensor or

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machine and expert system troubleshooting guides. This means the operator can sea a
schematic representation of the plant being controlled.
EX: alarm checking, calculations, logging and archiving; polling controllers on a set of
parameter, those are typically connected to the server.
Human machine interface:
The SCADA system uses human machine interface. The information is displayed and
monitored to be processed by the human. HMI provides the access of multiple control units
which can be PLCs and RTUs. The HMI provides the graphical presentation of the system. For
example, it provides the graphical picture of the pump connected to the tank. The user can
seethe flow of the water and pressure of the water. The important part of the HMI is an alarm
system which is activated according to the predefined values.
Fig : Human machine interface
For example: The tank water level alarm is set 60% and 70% values. If the water level reaches
above 60% the alarm gives normal warning and if the water level reach above 70% the alarm
gives critical warning.
Monitoring/Control:
The SCADA system uses different switches to operate each device and displays the status at
the control area. Any part of the process can be turned ON/OFF from the control station using
these switches. SCADA system is implemented to work automatically without human
intervention but at critical situations it is handled by man power.
DESIGN SCADA WITH INTOUCH WONDERWARE SOFTWARE AND APPLICATION:
SCADA is main interface between your control system and Operator. Maximum data and
features available on SCADA give you better control and clarity about the system. SCADA
needs to read data from various devices like:-
• PLC/Controllers

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• RTU
• Energy meters/Load managers/Data loggers
• Field instruments like Flow meters and positioners
Each of above data communicates with SCADA on various protocols . SCADA reads or writes
the data in format of tags.
INTOUCH WONDERWARE SCADA SOFTWARE:
First we crate the animated object from “Wizard Selection” tool than specify tag name as
require. We can create almost any screen animation effect imaginable. We can make objects
change colour, size, location, visibility, fill level, and so on.
Animation link selection dialog box are shown in fig
TOUCH LINK
A. User Input touch links:
Discrete: Used to control the value of a discrete tagname.
Analog: Used to input the value of an analog (integer or real) tagname.
String: Used to create an object into which a string message may be input.
B. Sliders touch links:
Vertical& Horizontal:
we can move the slider position horizontally or vertically.
C. Touch Pushbutton links:
Discrete Value:
Used to make any object or symbol into a pushbutton that controls the state of a discrete
tagname. Pushbutton actions can be set,reset, toggle,momentary on (direct) and momentary
off (reverse) types.

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Action:
Allows any object, symbol or button to have up to three different action scripts linked to it;
On Down, While Down and On Up.
Show Window:
Used to make an object or symbol into a button that opens one or more windows when it is
clicked or touched.
Hide Window:
Used to make an object or symbol into a button that closes one or more windows when it is
clicked or touched.
Fig : push button dialog box COLOR
LINKS:
Discrete:
Used to control the fill, line and text colours attributes of an object or symbol that is linked to
the value of a discrete expression.
Analog:
The line, fill, and text colour of an object or symbol can be linked to the value of an analog tag
name (integer or real) or an analog expression. Five value ranges are defined by specifying
four breakpoints. Five different colours can be selected which will be displayed as the value
range changes.
Discrete Alarm:
The text, line, and fill colour of an object can all be linked to the alarm state of a tag name,
Alarm Group, or Group Variable. This colour link allows a choice of two colours; one for the
normal state and one for the alarm stateof the tag name. This link can be used for both analog
and discrete tag names. If it is used with an analog tag name, it responds to any alarm
condition of the tag name.
Analog Alarm: The text, line, and fill colour of an object can all be linked to the alarm state of
an analog tag name, Alarm Group, or Group Variable. Allows a specific colour to be set for the
normal state as well as a separate colour for each alarm condition defined for the tag name.

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Fig : Fill colour dialog box
OBJECT SIZE LINKS:
We use Object Size links to vary the height and/or width of an object according to the value
of an analog (integer or real) tag name or analog expression. Size links provide the ability to
control the direction in which the object enlarges in height and/or width by setting the
"anchor" for the link. Both height and width links can be attached to the same object.
Fig : object height dialog box
PERCENT FILL LINKS:
We use Percent FillLinks to provide the ability to vary the filllevelof a filledshape(or a symbol
containing filled shapes) according to the value of an analog tag name or an expression that
computes to an analog value. For example, this link may be used to show the level of liquids
in a vessel. An object or symbol may have a horizontal fill link, a vertical fill link, or both.
Fig : vertical fill dialog box
LOCATION LINKS:
We useLocation Links to make an object automatically move horizontally, vertically, or in both
directions in response to changes in the value of an analog tag name or expression

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MISCELLANEOUS LINKS:
There are four type of miscellaneous links. Visibility:
Use to control the visibility of an object based on the value of a discrete tag name or
expression.
Blink:
Used to make an object blink based on the value of a discrete tag name or expression.
Orientation:
Used to make an object rotate based on the value of a tag name or expression.
Disable:
Used to disable the touch functionality of objects based on the value of a tag name or
expression.
VALUE DISPLAY LINKS:
Value Display Links provide the ability to use a text object to display the value of a discrete,
analog, or string tag name. There are three types:
Discrete :
Uses the value of a discrete expression to display an On or Off user defined message in a text
object.
Analog:
Displays the value of an analog expression in a text object.
String:
Displays the value of a string expression in a text object.
APPLICATIONS OF SCADA:
SCADA systems can be relatively simple, such as one that monitors environmental conditions
of a small office building, or incredibly complex, such as a systemthat monitors all the activity
in a nuclear power plant or the activity of a municipal water system. SCADA monitors and
controls industrial, infrastructure, or facility-based processes, as described below:
.

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• 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, wind farms, civil defence 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 HVAC, access, and energy
consumption.
Industries that are catered to are:
• Automotive
• Building Automation
• Cement & Glass
• Chemical
• Electronics
• Food and Beverage
• Machinery & Manufacturing
• Aerospace & Defence
• Metals & Mining
• Oil & Gas
• Pharmaceutical
• Power, Utilities & Generation
• Transportation
• Water & Wastewater
ADVANTAGES:
• The SCADA systemprovides on board mechanical and graphical information
• The SCADA system is easily expandable. We can add set of control units and sensors
according to the requirement.
• The SCADA systemability to operate critical situations.
Variable Frequency Drive (VFD)
A Variable FrequencyDrive isusedforapplicationswhereinspeedcontrolisof anessential importance
due to load changes whereinthe speed needs to be increased or decreased accordingly. Traditional
methods in existence have addressed this issue,each with their own drawbacks such as high motor
starting current, lower power factor, energy losses, etc. To address these problems, VFD provides a
flexible approach as compared to traditional methods of speed control especially for certain
applications which do not require a constant speed at all times. To name an example, a pump
delivering cooling liquid supply may require peak load operation only for a requisite period of time
and may require onlymuchlessamountduringthe remainderof the day.VFDwill allow the speedof
the pumpto run at a lowerrate insuch case therebyenablingenergysavingbenefits.

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V/f method of speed control
The motor speed can be controlled by varying supply frequency. Voltage induced in stator is
directly proportional to product of supply frequency and air-gap flux. If stator drop is
neglected, terminal voltage can be considered proportional to product of frequency and
flux. V1 α f.Φ Effect of supply frequency change without terminal voltage change:
1. Reduction of supply frequency without change in terminal voltage will cause an
increase in the air gap flux thereby saturating the motor. This will cause the increase in
magnetizing current, core loss and stator copper loss and cause distortion in line current
and voltage and produce high-pitch noise.
2. Increase of supply frequency without change in terminal voltage will cause decrease
in flux therefore leading to reduction of torque capability of the motor.
The base speedof theinductionmotorisdirectlyproportionaltothe supplyfrequencyandthenumber
of polesof the motor.Since itisnotpossibletochange the numberof poles,the onlyoptiontochange
the speed of the induction motor is by changing the supplyfrequency. The torque developedby the
inductionmotorisdirectlyproportionaltothe ratioof theappliedvoltageandthefrequencyof supply.
By changingthe voltage andthe frequency,butbykeepingtheirratioconstant,the torque developed
can be kept constant throughout the speed range. This is the main focus of V/f method of speed
control.Figure 3 showsthe torque-speedcharacteristicsof the inductionmotorwithVFcontrol
A constant V/f ratio produces a constant maximum torque, except at low speeds or
frequencies. The maximum torque will have lower value in motoring operation and larger
value in braking operation due to reduction in flux during motoring operation and increase in
flux during braking operation. The advantages of this method are:
1. Speed control of motor
2. Starting current required is lower.
3. Stable operating region of the motor is increased.
4. At base speed, the voltage and frequency achieve their rated values.
5. Acceleration and deceleration of the motor can be controlled by controlling the change of
supply frequency to the motor with respect to time.
Overview of the proposedmechanism

30. 30
A Variable Frequency Drive is a device used in a drive system consisting of the following three main
sub-systems:ACmotor,main drive controllerassembly,anddrive operatorinterface.The ACelectric
motor usedina VFD systemisa three-phase induction motorwhichisgenerallythe mosteconomical
motor choice. The VFD controller is a solid state power electronics conversion system consisting of
three distinctsub-systems:a rectifierbridge converter,a directcurrent link,andan inverter.Ina VSI
drive, the DC link consists of a capacitor which smoothens out the converter's DC output ripple and
providesastiff inputtothe inverter.ThisfilteredDCvoltageisconvertedtoquasisinusoidal ACvoltage
outputusingthe inverter'sactiveswitchingelements.VSIdrivesprovidehigherpowerfactorandlower
harmonic distortion than phase-controlled Current Source Inverter. VFD control has been chosen
specifically because they provide the advantages of energy savings, low motor starting current,
reduction of thermal and mechanical stresses on motors and belts during starts, simple installation,
high power factor and lower KVA. Variable Frequency Drives are generally required because many
applicationsare notrun at the same speedall of
the time due to surrounding circumstances.The
revolutions per minute of the driven shaft need
to be increasedordecreaseddependingonload
changes, application requirement or other
circumstances. The PLC has been connected to
control and monitora VFD whichis the acts as a
go between the three-phase induction motor
and the PLC.
Experimental setup
1. The Allen-Bradley PowerFlex 4M AC drive is the smallest and most
cost effective drive which provides powerful motor speed control in a
compact, space saving design.
Rated Output 0.75 kW (1 Hp)
Rated Voltage
240 V AC, single
phase
Rated Current 4.2 A
Rated Torque
3.5
kg
2. The PLC used in this project was Allen Bradley MicroLogix 1400 series.
The basic parts of a 1400 series PLC are Power Supply, CPU, Discrete
Input Module and Discrete Output Module.

31. 31
Description Details
1 Dimensions HxWxD 90 x 180 x 87 mm
2 Weight 0.9 kg
3 Number of I/O 24 inputs (20 digital 4
analog) and 14 outputs
(12 digital 2 analog)
4 Power supply voltage 24V DC
5 Power supply inrush
Current
24V DC: 15 A for 20 ms
6 Power consumption 50W
Input supply
frequency in
Hz
Motor speed in
rpm
0 0
5 250
10 620
15 940
20 1240
25 1495
30 1809
35 2100
40 2350
45 2590
50 2800
55 3200
60 3450
CONCLUSION:
With the speed of changing technology today it is easy to lose sight or knowledge of the basic
theory or operation of programmable logic. Most people simply use the hardware to produce
the results they desire. Hopefully, this report has given the reader a deeper insight into the
inner workings of programmable logic and its role in mechanical operations. The idea of
programmable logic is very simple to understand, but it is the complex programs that run in
the ladder diagrams that make them difficult for the common user to fully understand.
Hopefully this has alleviated some of that confusion. SCADA is used for the constructive
working, using a SCADA system for control ensures a common framework not only for the
development of the specific applications but also for operating the detectors. Operators
experience the same ”look and feel” whatever part of the experiment they control. However,
this aspect also depends to a significant extent on proper engineering.