RCDD Chapter 11 Field Testing (Non-core Area)

The correct answer is "All of the above" because telecommunications cabling in premises environments is indeed divided into three basic segments: campus (interbuilding) backbone, building (intrabuilding) backbone, and horizontal and centralized cabling. Each segment serves a specific purpose in establishing a comprehensive and efficient cabling infrastructure within a premises environment.

A visual fault locator operates in the visible light range because it uses a red laser diode to emit visible red light. This visible light helps in locating faults or breaks in fiber optic cables by allowing the user to visually identify the point of light leakage or loss. This makes it easier to identify and fix any issues with the fiber optic network.

The given answer "ok" is correct because it acknowledges the statement mentioned in the question. The question asks the reader to study a picture on a specific page to understand the appearance of a nonreflective splice or bend loss, as well as a reflective splice. The answer "ok" indicates that the reader understands and agrees to study the picture as instructed.

A Time Domain Reflectometer (TDR) is used to calculate the length of a cable by measuring the time it takes a pulse to travel down the cable and back. This device sends a pulse into the cable and measures the time it takes for the pulse to return after bouncing off any impedance changes or faults in the cable. By analyzing the time delay, the length of the cable can be determined accurately.

A Time Domain Reflectometer (TDR) is used to calculate the length of a cable by measuring the time it takes for a signal to travel down the cable and reflect back. By analyzing the round trip delay, the TDR can determine the length of the cable. FDR, DMM, and ACR are not typically used for this purpose.

Slice loss is not a field testing acceptance parameter for balanced twisted-pair cabling. Field testing acceptance parameters for balanced twisted-pair cabling typically include length, NEXT loss (Near-End Crosstalk), return loss, and insertion loss. Slice loss is not a commonly used parameter in the context of cabling testing and is therefore not considered as a field testing acceptance parameter.

When testing multimode fiber for end to end attenuation, it is necessary to wrap the test jumper attached to the source with five non-consecutive turns around a specifically-sized mandrel. A mandrel is a cylindrical object that is used to measure the diameter of a hole or tube. In this case, the mandrel ensures that the fiber is bent in a controlled manner, allowing for accurate measurement of attenuation. Wrapping the test jumper around the mandrel helps to simulate real-world conditions and ensures that the fiber is properly tested for attenuation.

The field-testing acceptance parameters for balanced twisted-pair cabling include wire map and length, insertion loss and return loss, NEXT, ELFEXT, PSNEXT, and PSELFEXT, as well as propagation delay and delay skew. Therefore, the correct answer is "All of the above."

Campus backbone cabling refers to the network infrastructure that connects various buildings or locations within a campus. This cabling is responsible for carrying a large amount of data traffic and connecting different network devices. Due to the critical nature of this infrastructure, extensive testing is necessary to ensure that the cabling is properly installed, configured, and functioning correctly. This testing helps identify any potential issues or faults in the cabling, ensuring reliable and efficient network connectivity throughout the campus. Therefore, the statement that campus backbone cabling requires extensive testing is true.

Power sum measurement is a method used to assess the crosstalk performance of multipair cables. Crosstalk refers to the interference between adjacent pairs in a cable, which can result in signal degradation. By conducting power sum measurements, cable manufacturers can ensure that their cables meet the required standards for crosstalk suppression. Therefore, it is true that power sum measurement is required for multipair cables.

An Optical Time Domain Reflectometer (OTDR) requires access to one end of the optical fiber in order to send pulses of light into the fiber and measure the strength of the power. This is because the OTDR uses the principle of backscattering to analyze the fiber and detect any faults or issues. By sending pulses of light from one end and measuring the reflections or backscattered light, the OTDR can determine the characteristics of the fiber and identify any problems.

Return loss is a measurement of the power reflected from the cabling, expressed in decibels (dB). It quantifies the amount of power that is reflected back towards the source due to impedance mismatches or defects in the transmission line. A higher return loss indicates a lower amount of reflected power, indicating better signal quality and less loss in the system.

Insertion loss refers to the reduction in signal power that occurs when a device is inserted into a transmission line or circuit. It is a measure of the signal loss introduced by the device. Attenuation, on the other hand, refers to the reduction in signal strength as it travels through a medium, such as a cable or a fiber optic line. Since insertion loss is a type of signal loss, it is synonymous with attenuation. Therefore, the correct answer is attenuation.

Return loss is a measure of the power reflected from a cable or any other device in a transmission system. It is expressed in decibels (dB) and indicates the amount of power that is reflected back towards the source due to impedance mismatches or other factors. A higher return loss value indicates a lower amount of reflected power, which is desirable for efficient signal transmission. Therefore, return loss is the correct measure for the power reflected from the cable.

Coaxial cabling is indeed used in broadband applications as it provides high bandwidth and is capable of carrying large amounts of data over long distances. It is also a low impedance media, with options of 50 or 75 ohm, which helps in reducing signal loss and interference. Coaxial cabling is typically used with a single transmission path, making it suitable for point-to-point communication. In the past, it was commonly used in local area networks for connecting computers and other devices. Therefore, all of the statements provided are true.

When field testing multipair or higher cabling, it is recommended that the cable be tested for the appropriate category (e.g. cat3 or cat 5e) in 4 pair increments as the pairs are configured in links. This means that the cable should be tested in groups of 4 pairs at a time, as this is how the pairs are typically configured in the cabling system. Testing in 4 pair increments ensures that all pairs are properly tested and allows for easier troubleshooting and identification of any issues that may arise.

Propagation delay refers to the time it takes for a signal to travel from one end of a transmission path to the other end. It is a measure of the delay or latency in the transmission of the signal. Propagation delay is influenced by factors such as the distance the signal needs to travel, the medium through which it is transmitted, and the speed of the signal. It is an important consideration in communication systems as it affects the overall performance and reliability of the transmission.

The statement is indicating that a larger value of ELFEXT loss in dB is associated with better performance. This means that as the ELFEXT loss increases, it indicates a greater reduction in crosstalk between adjacent cables, resulting in improved performance. Therefore, the answer is true.

Smaller value is better

A "Pass" result in testing cables indicates that the test falls within the accuracy range but at the accuracy limit of the field test instruments pass/fail boundary. This means that while the test is technically considered a pass, it should be viewed with caution. There may be some uncertainty or potential issues that need to be taken into account despite the passing result.

Level III instrument accuracy for field testing is defined for measurements up to category 6 and class E cabling. This means that Level III instruments are capable of providing accurate measurements for these types of cables and their associated categories.

A larger value of NEXT loss in dB indicates a higher level of crosstalk suppression between adjacent pairs of cables. This means that there is less interference or signal leakage between the cables, resulting in better performance. Therefore, the statement is true.

The display shows that the wires are transposed, meaning that they are switched or swapped with each other. This can be seen from the given mapping of wire numbers, where wire 1 is connected to wire 3, wire 2 is connected to wire 6, and so on. This indicates that the wires have been rearranged or interchanged in the cable.

The visible light range refers to the range of wavelengths of electromagnetic radiation that can be detected by the human eye. It extends from approximately 400 nanometers (nm) to 700 nm. This range includes different colors of light, with shorter wavelengths corresponding to violet and longer wavelengths corresponding to red. The answer "400-700 nm" correctly identifies the range of wavelengths within which visible light is found.

A higher value of return loss indicates that less power is being reflected back from a device or system, which implies better performance. This means that more of the transmitted power is being effectively utilized rather than being wasted or lost. Therefore, a larger value of return loss is desirable as it signifies improved performance.

When testing balanced twisted pair, if a field test instrument uses the same nominal velocity of propagation (NVP) for all pairs, the reported length will be different for each pair. This is because the electrical length of each pair can vary due to differences in the physical length and electrical characteristics of the cables. Therefore, when determining whether the test results pass or fail according to standards, the shortest electrical length among the pairs should be used as the basis. This ensures that the pair with the greatest potential for signal degradation or other issues is accounted for in the pass/fail decision.

The level of instrument accuracy for field testing defined for measurements up to category 5e and class D cabling is Level IIe. This level of accuracy ensures that the measurements taken are precise and reliable for this specific type of cabling.

The correct answer is (850 +-30 nm) or (1300 +-20 nm) because these wavelength ranges are commonly used for testing multimode optical fiber cabling. The first range, 850 +-30 nm, corresponds to the wavelength range used for testing multimode fiber using LED light sources. The second range, 1300 +-20 nm, corresponds to the wavelength range used for testing multimode fiber using laser light sources. These wavelength ranges are specified to ensure accurate and reliable testing of multimode fiber cabling.

The required tests or acceptance tests for testing coaxial cable depend on the application. Different applications may have different requirements and specifications for the cable, such as signal quality, bandwidth, or impedance. Therefore, the specific tests needed to ensure the cable meets these requirements will vary based on the application it will be used for.

A digital multimeter (DMM) is one of the most basic and widely used field test instruments available because it can measure multiple electrical quantities such as voltage, current, and resistance. It is portable, easy to use, and provides accurate readings, making it suitable for various applications in industries like electronics, electrical engineering, and telecommunications. Additionally, DMMs are versatile and can be used for troubleshooting, maintenance, and quality control purposes. They are essential tools for technicians and professionals working with electrical systems, making them a fundamental instrument in the field.

The mandrel diameters are based on nominal values of 20 mm (0.8 in) and 25 mm (1 in) reduced by the cable diameter and rounded up. This means that when determining the size of the mandrel needed for a particular cable, the nominal values of 20 mm and 25 mm are used as a starting point. The cable diameter is then subtracted from these values, and the result is rounded up to the nearest whole number. This ensures that the mandrel is slightly larger than the cable diameter, allowing for a proper fit and preventing any damage or distortion to the cable during the installation process.

The return loss is determined by calculating the ratio of the reflected voltage to the incident voltage. This ratio helps to measure the amount of power that is reflected back from a device or system compared to the power that is incident on it. A higher return loss indicates a better match between the impedance of the source and the load, resulting in less power being reflected. Conversely, a lower return loss indicates a poor match and more power being reflected.

The correct answer is (1310 +-10 nm) or (1550 +-20 nm). This means that when field testing optical fiber cabling for singlemode testing, the light source or OTDR must operate within the wavelength range of 1310 nm with a tolerance of +-10 nm, or within the wavelength range of 1550 nm with a tolerance of +-20 nm. These wavelength ranges are specific to singlemode testing and ensure accurate and reliable results.

A tone generator is a device that can generate a tone on one end of a pair of conductors, allowing for the identification of a specific pair. A cable tracer, on the other hand, is a tool used to trace and locate cables or wires. While both devices are used for cable identification, the tone generator specifically generates a tone on the conductors, making it the correct answer for this question. Fluke and wand are not relevant to the ability to identify a specific pair by generating a tone, so they are not the correct answers.

Power sum and crosstalk are not normally performed tests on coaxial cabling. Power sum is a test used to measure the total power of all signal pairs in a cable, which is not applicable to coaxial cables. Crosstalk is the interference caused by signals from adjacent cables, but coaxial cables are designed to minimize crosstalk, so it is not typically tested for.

Power sum measurements across all pairs are not practical with field test instruments.

The performance tests most often used on coaxial cabling are direct current (dc) loop resistance, impedance, and length. Direct current (dc) loop resistance measures the resistance of the cable, which affects the electrical current flow. Impedance refers to the resistance to the flow of electrical energy, and it is important for proper signal transmission. Length is crucial as it affects signal attenuation and loss. These tests help ensure the quality and efficiency of the coaxial cabling system.

The additional equipment used for optical fiber troubleshooting is a visual light source, also known as an optical fiber light-emitting diode (LED) or an optical flashlight. This device emits a light signal into the fiber, allowing technicians to visually inspect the fiber for any breaks, bends, or other issues. It helps in identifying and locating faults in the optical fiber system.

Time domain reflectometer (TDR) is a performance test commonly used on coaxial cabling. TDR measures the time taken for a signal to travel down the cable and reflect back, helping to identify any faults or disruptions in the cable. Attenuation is also frequently tested on coaxial cabling as it measures the loss of signal strength over a distance. Noise testing is important to identify any unwanted interference or disturbances that may affect the performance of the cable. Therefore, TDR, attenuation, and noise are the most often used performance tests on coaxial cabling.