CST Card Reader & Biometric Access 2 — Questions and Answers
Question 1: Which communication protocol is most commonly used between a card reader and an access control panel?
- RS-232
- Wiegand (Correct answer)
- Ethernet TCP/IP
- RS-485
Correct answer: Wiegand
Wiegand is the industry-standard protocol for transmitting card data from a reader to an access control panel.
Question 2: What is 'tailgating' in the context of access control?
- A reader malfunction caused by excessive card swipes
- An unauthorized person following an authorized person through a secured door (Correct answer)
- A biometric enrollment error that allows multiple users the same template
- A software glitch that grants access after hours
Correct answer: An unauthorized person following an authorized person through a secured door
Tailgating occurs when an unauthorized individual closely follows an authorized user through a secured entry point before the door closes.
Question 3: A proximity card reader stops responding after a nearby lightning strike. The most likely damaged component is the:
- Card credential itself
- Reader's surge protection or internal circuitry (Correct answer)
- Door strike mechanism
- Access control software database
Correct answer: Reader's surge protection or internal circuitry
Lightning-induced surges most commonly damage the reader's electronics, particularly if surge protection devices are absent or insufficient.
Question 4: OSDP (Open Supervised Device Protocol) provides an advantage over Wiegand because it:
- Operates at a lower voltage requiring less power
- Supports bidirectional encrypted communication between reader and panel (Correct answer)
- Is compatible with only HID credential formats
- Requires fewer wires for installation
Correct answer: Supports bidirectional encrypted communication between reader and panel
OSDP supports bidirectional, encrypted communication, allowing the panel to receive status from and send commands to the reader — unlike the one-way Wiegand protocol.
Question 5: When enrolling a finger for a fingerprint reader, best practice requires capturing how many sample scans?
- 1
- 2
- 3 to 5 (Correct answer)
- 10 or more
Correct answer: 3 to 5
Capturing 3 to 5 sample scans during enrollment creates a more robust biometric template and reduces false rejections.
Question 6: Which access card technology is considered the LEAST secure for high-security installations?
- 125 kHz proximity (HID Prox) (Correct answer)
- MIFARE DESFire EV2
- iCLASS SE
- SEOS
Correct answer: 125 kHz proximity (HID Prox)
125 kHz proximity cards transmit data unencrypted and can be easily cloned using inexpensive off-the-shelf equipment.
Question 7: A mantrap (or airlock) is used in physical security to:
- Prevent electromagnetic interference from entering server rooms
- Control access by allowing only one person to pass between two interlocked doors at a time (Correct answer)
- Store backup credentials offline
- Monitor card reader health via OSDP supervision
Correct answer: Control access by allowing only one person to pass between two interlocked doors at a time
A mantrap uses two interlocked doors so that the first must close and verify before the second opens, preventing tailgating and piggybacking.
CST Card Reader & Biometric Access 2
Which communication protocol is most commonly used between a card reader and an access control panel?