CML Security Systems Installation & Maintenance 3 — Questions and Answers
Question 1: What is the primary purpose of a tamper switch on an alarm system control panel?
- To reset the alarm after a trigger
- To detect unauthorized opening of the panel enclosure (Correct answer)
- To test backup battery capacity
- To adjust sensitivity of motion detectors
Correct answer: To detect unauthorized opening of the panel enclosure
Tamper switches generate an alert if the panel enclosure is opened without authorization, protecting the system's brain from physical defeat.
Question 2: Under NEC Article 760, low-voltage fire alarm wiring must be kept separate from which of the following?
- Telephone wiring
- Cat6 data cabling
- 120V or higher power wiring (Correct answer)
- Coaxial cable
Correct answer: 120V or higher power wiring
NEC 760 requires fire alarm conductors to be physically separated from power-limited and line-voltage electrical wiring to prevent interference and fire hazard.
Question 3: A dual-technology PIR/microwave motion detector reduces false alarms because it requires:
- Both technologies to trigger simultaneously before generating an alarm (Correct answer)
- Only the microwave sensor to confirm motion
- A minimum of three activations within 60 seconds
- Central station confirmation before signaling
Correct answer: Both technologies to trigger simultaneously before generating an alarm
Dual-tech detectors require both PIR (heat) and microwave (motion) channels to trigger together, drastically reducing false alarms from single environmental causes.
Question 4: What communication protocol do most modern commercial access control panels use to communicate with door-level controllers?
- RS-232 serial
- OSDP (Open Supervised Device Protocol) (Correct answer)
- Parallel port
- Analog 4-20mA loop
Correct answer: OSDP (Open Supervised Device Protocol)
OSDP is the industry-standard bidirectional protocol for secure, supervised communication between access control panels and door readers/controllers.
Question 5: When installing a video surveillance camera, the minimum recommended overlap between adjacent camera fields of view is:
- 5%
- 10–15% (Correct answer)
- 50%
- No overlap needed
Correct answer: 10–15%
A 10–15% overlap between adjacent camera views ensures there are no blind spots in coverage while avoiding excessive redundancy.
Question 6: A panic bar with a request-to-exit (REX) sensor on a controlled door is used to:
- Prevent tailgating at entry points
- Allow free egress while signaling the access system to suppress the door-forced alarm (Correct answer)
- Trigger a lockdown when pushed
- Control the maglock holding force
Correct answer: Allow free egress while signaling the access system to suppress the door-forced alarm
A REX sensor detects authorized exit motion and tells the access control system to shunt the door alarm briefly, preventing false alarms when someone legitimately exits.
Question 7: When testing a newly installed alarm system, which test should be performed first?
- Full central station signal test
- Walk-test of all motion detectors
- AC power failure test
- Communication path test to verify panel connectivity (Correct answer)
Correct answer: Communication path test to verify panel connectivity
Verifying that the panel can communicate with the central station or monitoring service must be confirmed first so that subsequent tests produce accountable signals.
CML Security Systems Installation & Maintenance 3
What is the primary purpose of a tamper switch on an alarm system control panel?