C7 Access Control & Surveillance Systems 2 — Questions and Answers
Question 1: Which communication protocol is most commonly used by modern IP-based access control panels to communicate with door controllers?
- RS-485
- TCP/IP over Ethernet (Correct answer)
- Wiegand
- OSDP
Correct answer: TCP/IP over Ethernet
Modern IP-based access control systems use TCP/IP over Ethernet to communicate between the head-end panel and networked door controllers.
Question 2: A biometric fingerprint reader fails to recognize enrolled users after a power outage. The MOST likely cause is:
- The reader's template database was stored in volatile RAM and was lost (Correct answer)
- The fingerprint scanner lens became dirty
- The Wiegand output pins corroded
- The door strike solenoid failed
Correct answer: The reader's template database was stored in volatile RAM and was lost
If biometric templates are stored in volatile RAM without battery backup, a power outage erases all enrolled templates.
Question 3: Under California Title 19 regulations, a fire alarm-integrated access control door must unlock upon:
- A supervisory signal only
- Any fire alarm signal activation (Correct answer)
- Manual request from the security console
- Loss of power to the access panel
Correct answer: Any fire alarm signal activation
California Title 19 requires that access-controlled doors in the egress path automatically unlock upon any fire alarm activation to allow safe evacuation.
Question 4: A PTZ camera's preset position drifts over time. Which component is MOST likely causing this issue?
- Worn pan/tilt motor encoders or gears (Correct answer)
- Dirty camera lens
- Incorrect IP address assignment
- Faulty video encoder card
Correct answer: Worn pan/tilt motor encoders or gears
Mechanical wear in pan/tilt motor encoders or gears causes positional drift in PTZ camera presets.
Question 5: What is the purpose of a 'mantrap' or 'sally port' in an access control installation?
- To provide a buffer zone where one door must close before the next opens, preventing tailgating (Correct answer)
- To house the main access control server in a secure room
- To route multiple card readers through a single panel
- To store backup power supplies for the access system
Correct answer: To provide a buffer zone where one door must close before the next opens, preventing tailgating
A mantrap (sally port) is an interlocked double-door vestibule that ensures only one door is open at a time, preventing tailgating into secure areas.
Question 6: When terminating shielded cable for a card reader, the shield drain wire should be connected to earth ground:
- At both ends to maximize noise rejection
- At the panel end only, leaving the reader end floating (Correct answer)
- At the reader end only
- Nowhere — shields should never be grounded
Correct answer: At the panel end only, leaving the reader end floating
Shielded cable for low-voltage control runs should be grounded at one end only (typically the panel end) to prevent ground loops.
Question 7: A CCTV system exhibits 'smearing' or bright streaks in the image when a light source appears in the frame. This artifact is known as:
- Blooming or smear caused by CCD sensor overexposure (Correct answer)
- Banding from 60 Hz electrical interference
- Barrel distortion from a wide-angle lens
- Compression artifacts from H.264 encoding
Correct answer: Blooming or smear caused by CCD sensor overexposure
Smearing or vertical streaks caused by bright light sources are a CCD sensor overexposure artifact called blooming or smear.
C7 Access Control & Surveillance Systems 2
Which communication protocol is most commonly used by modern IP-based access control panels to communicate with door controllers?