VDV Testing and Certification 5 — Questions and Answers
Question 1: Which organization awards the BICSI RCDD (Registered Communications Distribution Designer) credential that is closely associated with VDV system design standards?
- TIA
- BICSI (Correct answer)
- IEEE
- ANSI
Correct answer: BICSI
BICSI (Building Industry Consulting Service International) administers the RCDD credential, which validates expertise in ICT systems design and distribution.
Question 2: A technician measures an ACR-F (Attenuation to Crosstalk Ratio — Far End) of 5 dB on a Cat 6 link. What does this indicate?
- Excellent signal quality with strong headroom
- Poor performance; the crosstalk at the far end is only 5 dB below the signal level (Correct answer)
- The cable exceeds the 100-meter channel length
- Normal performance for a 10 Gigabit Ethernet application
Correct answer: Poor performance; the crosstalk at the far end is only 5 dB below the signal level
ACR-F of only 5 dB means the far-end crosstalk is nearly as strong as the attenuated signal, leaving very little headroom and indicating poor link performance.
Question 3: When testing a structured cabling system, what does the autotest feature of a certified cable analyzer do?
- Automatically repairs wiring faults
- Runs all required tests for the selected standard and compares results to pass/fail limits automatically (Correct answer)
- Uploads results to a cloud database
- Selects the correct cable category without user input
Correct answer: Runs all required tests for the selected standard and compares results to pass/fail limits automatically
The autotest feature runs the complete suite of measurements required by the selected standard (e.g., TIA-568-C.2 Cat 6) and automatically evaluates each result against the defined pass/fail limits.
Question 4: What is the purpose of an optical light source calibration reference measurement (reference method) before conducting fiber insertion loss tests?
- To warm up the laser to operating temperature
- To establish a baseline 0 dB reference so link losses are measured relative to a known starting point (Correct answer)
- To verify the fiber cable reel length
- To test the power meter battery level
Correct answer: To establish a baseline 0 dB reference so link losses are measured relative to a known starting point
The reference measurement establishes the starting power level (0 dB reference) so all subsequent loss measurements represent actual attenuation relative to a known input.
Question 5: A VDV technician documents test results and stores them in a certification report. Which information is typically NOT required in a cable certification report?
- Pass/fail status for each tested parameter
- Installer's personal home address (Correct answer)
- Cable ID and location identifiers
- Test equipment model and calibration date
Correct answer: Installer's personal home address
Certification reports require test data, equipment identification, calibration dates, and cable IDs, but personal contact details like home addresses are not part of the standard documentation.
Question 6: What does it mean when a field tester flags a result as '*PASS' (asterisk pass) rather than a clean 'PASS'?
- The test passed with significant margin above the limit
- The measurement passed but the result is within the accuracy uncertainty window of the tester (Correct answer)
- The tester detected a possible wiring fault that was automatically corrected
- The cable exceeds the required performance category
Correct answer: The measurement passed but the result is within the accuracy uncertainty window of the tester
An asterisk pass (*PASS) indicates the measured value passed the limit but falls within the measurement uncertainty range of the test instrument, meaning it could actually be a marginal fail.
Question 7: Which test is used to verify that a coaxial cable has the correct characteristic impedance, typically 75 ohms for video distribution systems?
- Time Domain Reflectometry (TDR) (Correct answer)
- DC resistance test
- Optical power test
- Wiremap continuity test
Correct answer: Time Domain Reflectometry (TDR)
TDR (Time Domain Reflectometry) sends a pulse down the coaxial cable and analyzes reflections to verify characteristic impedance and locate impedance discontinuities.
VDV Testing and Certification 5
Which organization awards the BICSI RCDD (Registered Communications Distribution Designer) credential that is closely associated with VDV system design standards?