CTS Installation and Systems Integration 5 — Questions and Answers
Question 1: What does the term 'headend' refer to in a distributed video system?
- The display at the end of a video run
- The central equipment location where sources are aggregated and distributed (Correct answer)
- The first device in a daisy-chain connection
- The head-mounted camera used in videoconferencing
Correct answer: The central equipment location where sources are aggregated and distributed
The headend is the central hub where all video sources are collected, processed, and then distributed to remote displays throughout a facility.
Question 2: During a multi-room AV installation, the technician discovers that power outlets in several locations are on circuits shared with HVAC equipment. What is the recommended course of action?
- Proceed with the installation and monitor for interference
- Request dedicated circuits for AV equipment from a licensed electrician (Correct answer)
- Use a standard surge protector to isolate the AV equipment
- Install a UPS on each shared circuit
Correct answer: Request dedicated circuits for AV equipment from a licensed electrician
HVAC equipment creates electrical noise and voltage fluctuations that can damage AV equipment or cause interference; dedicated circuits from a licensed electrician eliminate this risk.
Question 3: A technician is installing speakers in a plenum ceiling space. What cable type is required by the NEC for this installation?
- CM-rated cable
- CMP-rated (plenum-rated) cable (Correct answer)
- CMR-rated (riser) cable
- Any outdoor-rated cable
Correct answer: CMP-rated (plenum-rated) cable
The NEC requires CMP (Communications Plenum) rated cable in plenum spaces because it produces less smoke and toxic fumes when exposed to fire, protecting HVAC air pathways.
Question 4: What is the function of a balun in an AV installation?
- To amplify a signal over long distances
- To convert an unbalanced signal to balanced (or vice versa) or to transmit AV signals over twisted-pair cable (Correct answer)
- To regulate power supply voltage to displays
- To decode encrypted HDCP signals
Correct answer: To convert an unbalanced signal to balanced (or vice versa) or to transmit AV signals over twisted-pair cable
A balun converts between balanced and unbalanced signal formats and is commonly used to extend AV signals over Cat cable, reducing noise and extending transmission distances.
Question 5: When configuring a matrix switcher for a large installation, the technician should verify which parameter to prevent signal degradation when routing 4K content?
- The switcher's HDCP compliance and 4K/HDMI 2.0 bandwidth support (Correct answer)
- The number of available RS-232 ports
- The switcher's audio de-embedding capability only
- The front-panel button layout
Correct answer: The switcher's HDCP compliance and 4K/HDMI 2.0 bandwidth support
4K signals require HDMI 2.0 bandwidth (18 Gbps) and HDCP 2.2 compliance; a switcher lacking these specifications will fail to pass 4K HDR content correctly.
Question 6: A client reports that a motorized projection screen intermittently stops at inconsistent heights during descent. What is the most likely cause?
- Incorrect EDID setting on the connected projector
- A faulty or misadjusted limit switch on the screen motor (Correct answer)
- Insufficient amplifier gain in the audio system
- An IP address conflict on the control network
Correct answer: A faulty or misadjusted limit switch on the screen motor
Motorized screens use limit switches to define travel endpoints; a faulty or improperly adjusted limit switch causes the screen to stop at inconsistent positions.
Question 7: Which test should a CTS technician perform after completing all cable terminations in a structured wiring installation to verify proper connectivity and signal integrity?
- A visual inspection of connector colors only
- A cable certification test using a field tester that measures insertion loss, return loss, and NEXT (Correct answer)
- A simple continuity check with a multimeter
- An audio frequency sweep test only
Correct answer: A cable certification test using a field tester that measures insertion loss, return loss, and NEXT
Cable certification testing with a field tester validates all transmission parameters (insertion loss, NEXT, return loss) against TIA/ISO standards, confirming the installation will support the intended application.
CTS Installation and Systems Integration 5
What does the term 'headend' refer to in a distributed video system?