2.

2 DIRECT DATA ENTRY(DDE) DEVICES

• Direct data entry (DDE) devices are used to input data into a computer without the need for very
much, if any, human interaction.
• The transfer of the data to the computer is done automatically.
Types of DDE devices
1. Barcode Readers Disadvantages: Disadvantages:
Uses:  Multiple formats available  Requires physical contact
 Supermarkets for product  Can transmit malicious codes  Can be damaged by magnetic
scanning 3. RFID Readers fields
 Libraries for book tracking Components: b) Contactless Card Readers
 Safety testing of electrical  Microchip for data storage Features:
components  Antenna for data transmission  Uses radio waves
Advantages: Uses:  Works within few centimeters
 Faster than manual data entry  Livestock tracking  128-bit encryption
 Fewer errors  Retail inventory Advantages:
 Enables automatic stock  Library management  Faster transactions
control  Admission passes  Secure encryption
Disadvantages: Advantages:  No typing errors
 Relatively expensive system  No line-of-sight needed Disadvantages:
 Can be damaged easily  Fast read rate  More expensive
 Not foolproof (barcodes can  Bidirectional data transfer  Potential for double charging
be swapped) Disadvantages:  Vulnerable to close-range
2. QR Code Readers  Tag collision issues scanning
Capabilities:  Vulnerable to jamming
 Can hold up to 4296  More expensive than barcodes
characters or 7089 digits 4. Card Readers
 Matrix of dark squares on a) Magnetic Stripe Readers
light background Uses:
Uses:  Credit/debit cards
 Advertising  Building access
 Business information sharing  ATMs
 WiFi authentication Advantages:
 Virtual stores  Fast data entry
Advantages:  Error-free
 Higher data capacity  Robust design
 Built-in error checking
 Easy to read and transmit
6.1 communication
What is communication media?

• Communication media describes the tools and channels for sharing of information between a sender
and a receiver.
• Communication media can be both electronic and physical.
Types of Communication Media:
1. Newsletters
 Periodic publications for informing, educating, or entertaining subscribers
 Distributed through email or printed copies
 Used by organizations, schools, and clubs to keep members updated
2. Posters
 Visual presentations that convey information or promote events/products
 Combines text, images, and graphics to grab attention
3. Websites
 Online platforms providing information or services
 Accessed through web browsers
 Used by businesses, educational institutions, and individuals
 Purposes: sharing information, selling products, offering services
4. Multimedia Presentations
 Digital presentations combining text, images, audio, and video
 Used in education, business, and entertainment
 Makes information visually engaging
5. Media Streaming
 Real-time transmission of audio/video files over internet
 No downloading required
 Examples: Spotify, Netflix, YouTube
Requirements:
 Stable internet (minimum 25 Mbits/second for HD)
 Uses buffering for smooth playback
 Data sent in packets
6. E-Publications
 Digital versions of printed materials (eBooks, eMagazines, eNewspapers)
 Read on eReaders, tablets, smartphones
 Benefits: portability, searchability, adjustable text size
6.1.2 Mobile Communications

Basic Network Structure:

 Each cell has a tower at the center
 Cells overlap to avoid signal loss
 Phones automatically switch towers when moving between cells
Communication Methods:  Limitations:
1. SMS (Short Message Service)  Sound quality varies
 Quick and low-cost communication  Depends on good network quality
 Messages can be sent even when phone is off  Security concerns
 Features: 4. Mobile Internet Access
 Predictive texting  Connects via:
 Frequently used word memory  Mobile network
 Faster than phone calls in many cases  Wi-Fi
2. Phone Calls  Wi-Fi advantages:
 Main use of mobile phones  Cheaper
 Allows communication on the move  Uses less power
 Benefits:  Better speed and data limits
 No need for public phones  Websites adjust layout for smaller screens
 Stay in touch anywhere
 Convenient for emergencies and business SIM Cards and Wireless Connectivity:
3. VoIP and Video Calling  SIM card connects phone to mobile network
 Voice over Internet Protocol uses internet for  Enables:
calls  SMS messaging
 Examples: Skype, WhatsApp  Phone calls
 Features:  VoIP
 Converts voice to digital data packets  Video calling
 Free calls, even long-distance  Internet access
 Uses device's built-in microphone
6.2 Modelling Applications
• A simulation is the creation of a model of a real system in order to study the behaviour of the system.
• The model is computer-generated and is based on mathematical representations.
• The whole idea is to try and find out how a system behaves, predict the behaviour of the system in the
future and see if it is possible to influence this future behaviour.
Types of Modelling Applications:  Various times of day
1. Personal Finance  Different speed limits
 Uses spreadsheets for:  Effects of breakdowns
 Testing 'what if' scenarios  Optimal traffic flow
 Checking financial impact of changes
 Modeling profit/loss B. Traffic Light Simulation
 Example: Testing impact of household income  Data needed:
changes  Vehicle counts in all directions
2. Bridge and Building Design  Time of day patterns
 Used before construction starts  Queue lengths
 Uses 3D computer modeling  Junction clearance times
 Testing scenarios include:  Special conditions (weekends, holidays)
 Traffic capacity  Real-life implementation:
 Effects of strong winds  Road sensors gather data
 Earthquake resistance  Data sent to control box/computer
 Tidal waves and ice floes  System compares with stored data
 Vibration effects  Traffic light timing adjustments
 Features: 5. Weather Forecasting
 Zoom capability for fine details  Uses automatic weather stations
 Multiple viewing angles  Measures:
 Pre-construction flaw detection  Rainfall
 Scenario testing  Temperature
3. Flood Water Management  Wind speed/direction
 Uses computer models for:  Barometric pressure
 Risk assessments of flooding areas  Humidity
 Automated flood defense systems  System features:
 Water level predictions  Hourly data collection
 Water flow calculations  Three-dimensional atmospheric grid
 Benefits:  Continuous learning from comparisons
 Real-time monitoring  Regular updates for predictions
 Data collection
Features of Computer Modeling:
 Faster response to changes
 Based on mathematical representations
 Advance warning systems
 Predicts future behavior
4. Traffic Management
 Tests multiple scenarios
A. Motorway Lane Closures
 Helps optimize solutions
 Models test:
 Reduces real-world risks
 Different traffic densities
6.3 computer controlled system
Robotics is the principle of a robot carrying out a task by following a precise set of programmed instructions.

1. Robotics in Manufacturing  High maintenance costs

Applications: 4. Production Line Control
 Paint spraying of car bodies Example: Bottling System Process
 Welding bodywork on cars  Filling bottles with liquid
 Manufacturing microchips  Capping the bottles
 Manufacturing electrical goods  Applying labels
 Stock movement in automatic warehouses  Continuous operation with robots at each
Features: station
 Equipped with sensors Benefits:
 Controlled by built-in microprocessors  Faster operations
 Can gather information about surroundings  Greater productivity
 Can perform different tasks with different  Consistent quality
end-effectors  Built-in quality control
2. Advantages of Using Robots  Reduced consumer costs
 Can work in harmful environments 5. Key Considerations
 24/7 operation capability  Tasks must be precisely programmed
 Cost-effective long-term  Sensors prevent operational errors
 Higher productivity (no holidays needed)  Different robots for specific tasks
 Greater consistency in production  Continuous monitoring required
 Can perform repetitive tasks  Regular maintenance needed
 Adaptable with different end-effectors
 Built-in quality control Safety and Operation:
3. Disadvantages of Using Robots  Robots follow exact programming
 Difficulty with unusual/one-off tasks  Sensors prevent accidents
 Can cause higher unemployment  Quality control built into process
 Risk of losing certain skills (e.g., welding)  Continuous operation possible
 Factories can relocate anywhere  Multiple robots work together in sequence
 Expensive initial setup