Know and understand characteristics, uses, advantages and disadvantages of direct data entry devices including magnetic stripe reader, chip and PIN reader, Radio Frequency Identification (RFID) reader, Optical Mark Recognition/Reader (OMR), Optical C

2. Input and Output Devices – Direct Data Entry Devices

This set of notes covers the characteristics, typical uses, advantages and disadvantages of the most common direct data‑entry devices used in modern ICT environments.

1. Magnetic Stripe Reader

• Characteristics

  • Reads magnetic stripe on cards (usually 3 tracks, 7‑track or 13‑track).
  • Uses a magnetic head to detect changes in magnetic flux as the card is swiped.
  • Outputs data as a string of alphanumeric characters.

• Typical Uses

  • Credit/debit card transactions.
  • Access control cards (e.g., hotel key cards).
  • Transport tickets and loyalty cards.

• Advantages

  • Low cost and widely available.
  • Fast read time (typically < 0.5 s).
  • Simple integration with POS and access‑control systems.

• Disadvantages

  • Data can be easily cloned or skimmed.
  • Physical wear of the stripe reduces reliability.
  • Limited data capacity (usually < 100 bytes).

2. Chip and PIN Reader (EM \cdot Reader)

• Characteristics

  • Reads integrated circuit (IC) chip embedded in a card.
  • Requires a PIN entry for authentication.
  • Communicates via contact (insert) or contactless (NFC) interface.

• Typical Uses

  • Secure payment terminals.
  • Banking ATMs.
  • High‑security access control.

• Advantages

  • Enhanced security – data is encrypted and dynamic.
  • Higher transaction limits than magnetic stripe.
  • Reduced fraud risk.

• Disadvantages

  • Higher equipment cost.
  • Longer transaction time (especially with PIN entry).
  • Requires regular software updates to stay compliant.

3. Radio Frequency Identification (RFID) Reader

• Characteristics

  • Uses radio waves to communicate with RFID tags (passive, active, or semi‑passive).
  • Read range varies from a few centimeters to several meters.
  • Can read multiple tags simultaneously (anti‑collision protocols).

• Typical Uses

  • Inventory management and asset tracking.
  • Contactless payment (e.g., transit cards).
  • Access control and attendance systems.

• Advantages

  • No line‑of‑sight required.
  • Fast bulk reading.
  • Durable tags – can withstand harsh environments.

• Disadvantages

  • Potential interference from metal or liquids.
  • Privacy concerns – tags can be read without user knowledge.
  • Higher initial setup cost for readers and tags.

4. Optical Mark Recognition (OMR) Reader

• Characteristics

  • Detects the presence or absence of marks (usually dark ink) in predefined positions.
  • Works with paper forms such as answer sheets, surveys, and ballots.
  • Outputs binary data (marked = 1, unmarked = 0).

• Typical Uses

  • Examination answer sheets.
  • Customer feedback questionnaires.
  • Voting ballots.

• Advantages

  • Very fast processing of large volumes.
  • Low error rate when forms are correctly filled.
  • Simple hardware – inexpensive compared with OCR.

• Disadvantages

  • Requires specially designed forms.
  • Cannot read handwritten or printed text.
  • Mark quality (e.g., light pencil) can affect accuracy.

5. Optical Character Recognition (OCR) Reader

• Characteristics

  • Converts printed or handwritten characters into machine‑readable text.
  • Uses pattern recognition and, increasingly, AI algorithms.
  • Can process scanned documents, photos, or live camera feeds.

• Typical Uses

  • Digitising printed archives.
  • Automated data entry from invoices, receipts, and forms.
  • Assistive technology for the visually impaired.

• Advantages

  • Reduces manual typing effort.
  • Enables searchable digital documents.
  • Can handle multiple languages and fonts (with appropriate training).

• Disadvantages

  • Accuracy drops with poor image quality or unusual fonts.
  • Handwritten text remains challenging.
  • Requires post‑processing (proofreading) for critical data.

6. Bar Code Reader

• Characteristics

  • Uses a light source (laser or LED) and a photodiode to detect reflected light from printed bars.
  • Decodes 1‑dimensional (1D) barcodes such as UPC, EAN, Code 39.
  • Outputs a numeric or alphanumeric string.

• Typical Uses

  • Retail point‑of‑sale scanning.
  • Warehouse inventory control.
  • Asset tagging and tracking.

• Advantages

  • Very low cost and mature technology.
  • Fast read times (milliseconds).
  • Simple integration with databases.

• Disadvantages

  • Requires a clear line of sight.
  • Limited data capacity (typically < 20 characters).
  • Print quality affects readability.

7. QR Code Scanner (2‑Dimensional Barcode Reader)

• Characteristics

  • Captures a matrix of black and white squares using an imaging sensor.
  • Can store up to several thousand alphanumeric characters.
  • Often combined with smartphone cameras or dedicated scanners.

• Typical Uses

  • Mobile payments and ticketing.
  • Linking to URLs, contact details, or product information.
  • Inventory and asset management where space is limited.

• Advantages

  • High data density in a small area.
  • Can be read from any orientation.
  • Resilient to damage – error‑correction algorithms.

• Disadvantages

  • Requires a camera‑based reader (more complex than laser scanners).
  • Scanning may be slower on low‑resolution devices.
  • Security concerns if QR codes link to malicious sites.

Summary Comparison Table