Presentation on Touch Screens and SCADA

1. TOUCH SCREENS
ELEMENTARY COURSE
1
PREPARED BY MIHLA BIYASE

2. TOUCH SCREENS
CONTENTS
1.0 INTRODUCTION……………………………………………………………………………………………………………………………………………….4
1.1 HISTORY …………………………………………………………………………………………………………………………………………………………………………………………..5
2.0 COMPONENTS ………………………………………………………………………………………………………………………………………………..6
2.1 TOUCH SENSOR ………………………………………………………………………………………………………………………………………………………………………………7
2.2 CONTROLLER……………………………………………………………………………………………………………………………………………………………………………………8
2.3 SOFTWARE DRIVER …………………………………………………………………………………………………………………………………………………………………………9
3.0 DIFFERENT TOUCH SCREEN TECHNOLOGIES…………………………………………………………………………………………...........10
3.1 RESISTIVE TOUCH SCREEN ………………………………………………………………………………………………………………………………………………………………11
3.2 CAPACITIVE TOUCH SCREEN…………………….……………………………………………………………………………………………………………………………...........12
3.3 SURFACE ACCOUSTIC WAVE ……………………………………………………………………………………………………………………………………………………………13
3.4 INFRARED TOUCHSCREEN …………………………………………………………………………………………………………………………………..14
4.0 COMPARISON CHART……………………………………………………………………………………………………………………………………….15
5.0 APPLICATIONS………………………………………………………………………………………………………………………………………………….16
5.0 VIDEO SESSION ……………………………………………………………………………………………………………………………………………….16
6.0 PRACTICAL….……………………………………………………………………………………………………………………………………………………17
7.0 ASSESSMENT……………………………………………………………………………………………………………………………………………………18
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3. INTRODUCTION
A touch screen is a display that
can detect the presence and
location of a touch within the
display area.
Touch screen can also sense
other passive objects such as
stylus
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4. HISTORY
4

5. COMPONENTS
A basic touch screen has three main components:
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Touch sensor Controller Software drive

6. 1. TOUCH SENSOR
A touch sensor is a clear glass
panel with a touch responsive
surface which is placed over a
display screen.
The sensor generally has an
electrical current or signal going
through it and touching the screen
causes a voltage or signal change.
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7. 2. CONTROLLER
The controller is a small PC
card that connects between
the touch sensor and the PC.
It takes information from
the touch sensor and
translate it into information
that PC can understand
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8. 3. SOFTWARE DRIVER
The driver is a software that allows
the touch screen and computer to
work together.
It tells the operating system how to
interpret the touch event information
that is sent from the controller.
Most touch screen drivers today are
mouse-emulation type drivers. This
makes touching the screen the same
as clicking your mouse at the same
location on the screen.
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9. DIFFERENT TOUCH SCREEN
TECHNOLOGIES
RESISTIVE
CAPACITIVE
SURFACE WAVE
INFRARED
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10. RESISTIVE TOUCH SCREEN
Polyester Film
Top Resistive Layer
Conductive Transparent Metal
Coating
Bottom Resistive Layer
Insulating Dots
Glass Substrate
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11. RESISTIVE TOUCH SCREEN
Pressing the flexible top sheet creates
electrical contact with the coating on
the glass
The touch screen controller gets the
alternating voltages between the two
layers and converts them into the
digital X and Y coordinates of the
activated area.
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12. RESISTIVE TOUCH SCREEN
ADVANTAGES
high resistance to liquids
Low cost solution
Low power consumption
DISADVANTAGES
Poor durability
Poor contrast
risk of damage due to sharp
objects
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13. CAPACITIVE TOUCH SCREEN
In the capacitive system, a layer that stores
electrical charge is placed on the glass panel
When a user touches, some of the charge is
transferred to the user, so the charge on the
capacitive layer decreases.
This decrease is measured in electrodes
located at each corner of the monitor.
The computer then calculates the
coordinates, from the relative differences in
charge at each corner
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14. CAPACITIVE TOUCH SCREEN
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Small amount of voltage is
applied to the four corners
of the touchscreen
A finger touches the screen
and draws a minute
amount of current to the
point of contact
The location of the point of
contact is calculated by the
controller

15. CAPACITIVE TOUCH SCREEN
ADVANTAGES
More durable
Very responsive
ADVANTAGES
Accepts inputs from finger only
Accuracy is dependent on
capacitance of person
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Capacitive touchscreens are usually used in smartphones.

16. SURFACE ACCOUSTIC WAVE
In this type of touchscreen, there are two
transducers* placed on the x and y axes that
constantly emit sound waves.
Reflectors are placed opposite the
transducers and reflect those signals.
An interruption in the sound waves, i.e. a
touch, causes a change in the amplitude of
those waves.
The hardware controller and driver can then
calculate where that occurred.
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*Transducer - a device that converts variations in a physical quantity, such as pressure or brightness, into an electrical signal, or
vice versa.

17. SURFACE ACCOUSTIC WAVE
ADVANTAGES
high resolution
long life
DISADVANTAGES
fairly expensive
easily interfered with by
contaminants such as dirt or water
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SAW touchscreens are typically used in public info kiosks due to their long
life.

18. INFRARED TOUCHSCREEN
This type of touchscreen has an array of x
and y axes across the screen.
The lines of this array are fitted with
infrared LEDs and photodetectors.
The LEDs constantly emit a light, and a
touch applied to the screen interrupts that.
The photodetectors can tell when there is a
change in that light and calculates where
that occurs.
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19. INFRARED TOUCHSCREEN
ADVANTAGES
 wide range of objects can be
used to register a touch
DISADVANTAGES
 Low resolution,
Susceptible to contaminants like
dirt or water
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Infrared touchscreens are usually used for multi-touch capabilities.

20. COMPARISON CHART
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Resistive Capacitive SAW Infrared
Touch
Resolution
High High Average High
Clarity Average Good Good Good
Operation Finger or
Stylus
Finger or
Stylus
Finger or
Soft-tipped
Stylus
Finger only
Durability Can be
Damaged
by sharp
objects
Highly
Durable
Susceptible
Dirt and
Moisture
Highly
durable

21. APPLICATIONS
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22. VIDEO SESSION
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23. PRACTICALS
IDENTIFYING DEFERENT TOUCH
SCREENS
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24. ASSESSMENT
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25. SCADA
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ELEMENTARY COURSE
PREPARED BY MIHLA BIYASE

26. SCADA
CONTENTS
1.0 INTRODUCTION……………………………………………………………………………………………………………………………………………….27
1.1 HISTORY.…………………………………………………………………………………………………………………………………………………………………………………………..28
2.0 FUNCTIONS……………………………………………………………………………………………………………………………………………………..29
2.1 WHY DO WE USE SCADA.…………………………………………………………………………………………………………………………………………………………………30
3.0 SCADA COMPONENTS………………………………..…………………………………………………………………………………………...........31
3.1 RESISTIVE TOUCH SCREEN.………………………………………………………………………………………………………………………………………………………………32
3.2 HMI………………………………………………………….……………………………………………………………………………………………………………………………...........33
3.3 SUPERVISORY SYSTEM………..……………………………………………………………………………………………………………………………………………………………34
3.4 PLCs……………………………….………………………………………………………………………………………………………………………………..35
3.5 SCADA PROGRAMING…..……..……………………………………………………………………………………………………………………………..36
3.6 COMMUNICATION INTERFACE..….………………………………………………………………………………………………………………………..37
4.0 INDUSTRIAL USAGE...………………………………………………………………………………………………………………………………………38
4.0 ADVANTAGES AND DISADVANTAGE………………………………………………………………………………………………………………….40
5.0 PRACTICAL……………………………………………………………………………………………………………………………………………………….16
5.0 CONCLUSION……………………………………………………………………………………………………………………………………………………41
6.0 ASSESSMENT……………………………………………………………………………………………………………………………………………………42
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27. INTRODUCTION
SCADA - Supervisory Control And Data
Acquisition
This is an industrial computer-based control
system used to acquire real-time data to keep
track, monitor and control industrial equipment
at the supervisory level
It is a combination of software, hardware and
protocols.
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28. HISTORY
Before the concept of SCADA, industrial plants and remote sites relied
on personnel to manually control and monitor equipment via push
buttons and analog dials.
Industrial organizations started to utilize relays and timers to provide
some level of supervisory control without having to send people to
remote locations to interact with each device
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29. FUNCTIONS
The important functions of an SCADA are listed below:
 Data Acquisition
 Information Display
 Supervisory Control
 Alarm Processing
 Information Storage and Reports
 Sequence of Event Acquisition
 Data Calculation 8. Special RTU Processing/Control
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30. WHY DO WE USE SCADA
Ability to collect data & control process from distance.
Ability to create logs on system’s current and past state
Ability to send necessary information to operators in real time using
SMS and internet.
Reduces man-power needs
Saves Energy, Time and Money
Reliable
Supervisory control over a particular system
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31. SCADA COMPONENTS
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 Basic Block diagram of SCADA system

32. HUMAN-MACHINE INTERFACE
(HMI)
This is an input-output device that presents the
data to be controlled by a human operator.
It is used by linking the SCADA system’s
software program for providing information,
including the scheduled maintenance
procedures, detailed schematics, trending and
diagnostic data for specific sensor or machine.
HMI systems facilitate the operating personnel
to see the information graphically
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33. SUPERVISORY SYSTEM
Supervisory system is used as server for communicating
between the equipment of the SCADA system such as RTUs,
PLCs and sensors, etc., and the HMI Software used in the
control room workstations.
Master stations comprises a single PC in smaller SCADA
systems and, in case of larger SCADA systems, it comprises
distributed software applications, disaster recovery sites and
multiple servers.
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34. REMOTE TERMINAL UNITS
Physical objects in the SCADA systems are
interfaced with the microprocessor controlled
electronic devices called as Remote Terminal
Units (RTUs).
These units are used to transmit telemetry
data to the supervisory system and receive
the messages from the master system for
controlling the connected objects.
These are also called as Remote Telemetry
Units.
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35. PROGRAMMABLE LOGIC
CONTROLLERS
In SCADA systems, PLCs are connected to the
sensors for collecting the sensor output signals
in order to convert the sensor signals into
digital data.
PLCs are used instead of RTUs because of the
advantages of PLCs like flexibility,
configuration, versatile and
affordability compared to RTUs.
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36. SCADA PROGRAMING
SCADA programming in a master or
HMI is used for creating graphs and
diagrams which will give an important
situational information in case of an
event failure or process failure.
SCADA programming can be done
using derived programming language
or C language 24
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37. COMMUNICATION INTERFACE
Generally the combination of radio and
direct wired connections is used for SCADA
systems, but in case of large systems like
power stations and railways wireless
network are frequently used.
•Private Network (LAN/RS-485)
•Internet
•Wireless Communication systems
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38. INDUSTRY USAGE
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AIRPORTS UTILITIESMANUFACTURING

39. INDUSTRY USAGE CONT.
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AIRPORTS DISTRIBUTION

40. ADVANTAGES AND DISADVANTAGES
ADVANTAGES
Reduce time consumption
Reduce human resource
consumption
Greater accessibility (remotely)
Instantaneous alert on alarms or
events
Organized data records and report
generation automatically
DISADVANTAGES
Can be expensive in the scenarios
where PLC is enough to handle the
job.
SCADA system needs
maintenance. If you are the end
user- it means more yearly
recurring cost.
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41. PRACTICAL
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ASSEMBLY P.C.R VISIT

42. CONCLUSION
SCADA plays a very crucial role in the world of automation with its ability
to:
Acquire quantitative measurements immediately and over time
 Detect, Diagnose and correct problems as soon as they arise
 Measure trends over time and prepare reports and charts
 Discover and eliminate bottlenecks over time and improve efficiency
Ability to Control large and complex processes with a few specialized
staff.
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43. SCADA ASSESSMENT
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