Term
016-1. Which control do you use to select the meter’s different measurement functions? |
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Definition
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Term
016-2. List the four types of information presented in the multimeter’s display section. |
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Definition
(1) Digital display. (2) Visual annunciators. (3) Analog bar graph. (4) Range indicator. |
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Term
016-3. Which information in the display section shows the absolute value of the input? |
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Definition
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Term
016-4. Describe the function of the range push button. |
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Definition
Lets you manually select the measurement range |
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Term
016-5. What is the purpose of the touch-hold push button? |
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Definition
Locks the measurement into the display for viewing and automatically updates the display when you take a new measurement. |
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Term
016-6. List the multimeter’s four input jacks. |
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Definition
(1) Amperes. (2) Milliamps/microamps. (3) Volts/ohms/diode. (4) Common. |
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Term
016-7. When does the 8025A perform a power-up self test? |
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Definition
When you move the rotary switch to any position from the OFF position. |
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Term
017-1. What two ranges of DC voltages can you measure using the 8025A multimeter? |
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Definition
(1) −1,000 to +1,000 volts DC. (2) −320 to +320 millivolts DC. |
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Term
017-2. What is the maximum amount of continuous AC current that you can measure with the multimeter? |
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Definition
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Term
017-3. When using the Fluke 8025A, how do you know you’re in the resistance measurement function? |
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Definition
The Ω annunciator is showing in the display |
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Term
017-4. How do you determine if you’re testing a “good” diode with the 8025A? |
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Definition
Placing the leads across a “good” diode produces “OL” in the display while reversing the leads produces a continuous audible tone. |
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Term
018-1. What type of display does the oscilloscope present? |
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Definition
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Term
018-2. On which axis of an oscilloscope is voltage, time, and depth information presented? |
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Definition
Voltage = vertical axis, time = horizontal axis, and depth = intensity |
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Term
018-3. What is the purpose of the delay line at the input of the vertical amplifier? |
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Definition
It allows the sweep generator circuitry time to start a sweep before the signal reaches the cathode ray tube vertical deflection plates. This enables you to view the leading edge of the signal waveform. |
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Term
018-4. What position of the input coupling switch is used to view digital-type or square wave signals? |
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Definition
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Term
019-1. What is the basic purpose of the oscilloscope probe? |
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Definition
To provide isolation for scope inputs and prevent circuit loading. |
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Term
019-2. List four types of probes? |
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Definition
(1) The high resistance. (2) Passive divider and x1 probes. (3) Active (field effect transistor). (4) Current probes. |
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Term
019-3. What is the typical input impedance of most oscilloscopes? |
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Definition
One megaohm shunted by 20 pF of capacitance |
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Term
019-4. When making an amplitude measurement and the source impedance is unknown, greatest accuracy is achieved when the probe’s Z is what? |
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Definition
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Term
020-1. What is the biggest difference between digital storage oscilloscopes and analog scopes? |
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Definition
Digital storage oscilloscopes digitize the input signal for storage or display. |
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Term
020-2. What is the function of charged coupled devices in the digital storage oscilloscope’s signal sampling process? |
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Definition
Charged coupled devices accept fast-changing data and send it to the analog-to-digital-converter at a slower rate for more accurate data collection. |
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Term
020-3. Define the following waveform storage terms: a) Waveform points. b) Waveform record. c) Record length. |
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Definition
(a) Sampled data points stored in the digital storage oscilloscopes memory. (b) Stored waveform points that make up the waveform record. (c) Number of waveform points used to make the waveform record. |
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Term
020-4. What advantage does retrieving data from memory have on the cathode ray tube? |
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Definition
It allows the cathode ray tube to receive data at a slower rate as opposed to keeping up with some of the high frequency signals fired directly on a cathode ray tube in an analog scope. |
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Term
020-5. List two digital storage oscilloscope sampling techniques. |
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Definition
(1) Real-time. (2) Repetitive-sampling. |
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Term
020-6. Define interpolation. |
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Definition
This is a process that estimates what the signal will look like between samples and “fills in the blanks” between data points. |
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Term
020-7. What are the two types of interpolation? |
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Definition
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Term
020-8. What is the difference between sequential and random sampling? |
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Definition
Sequential sampling takes a sample at a predetermined time after the trigger in a progressive order until there are enough data points to reconstruct several periods of the signal. Random sampling takes samples at an undetermined point on a signal and stores them. |
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Term
020-9. What is a common cause of aliasing? |
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Definition
Undersampling due to having the time base turned down too low, thus reducing the sample rate for a frequency that is too high for a given setting. |
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Term
020-10. Describe the three types of acquisition modes. |
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Definition
(1) In sample mode, the digital storage oscilloscope creates a record point by saving the first sample in a collection of sample points. (2) In peak detect mode, the digital storage oscilloscope saves the highest and lowest points in a collection of samples. (3) In averaging mode, the digital storage oscilloscope shows a record that is a collection of several acquisitions of a repeated signal that is averaged over time. |
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Term
020-11. What is the function of the acquisition controls? |
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Definition
To set the digital storage oscilloscope’s sampling rate, determine what type of processing will occur and how many record points can be shown. |
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Term
020-12. What is the range of record points that the Tektronix 2230 digital storage oscilloscope can acquire? |
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Definition
1,000 (1K) to 4,000 (4K) points. |
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Term
020-13. Which control sets up acquisition either before a trigger or at the beginning of a waveform? |
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Definition
PRETRIG/POST TRIG switch. |
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Term
020-14. What happens to the NORM and P-P AUTO trigger modes while in ROLL mode? |
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Definition
These triggers are disabled allowing the digital storage oscilloscope to continuously acquire and display incoming signals. |
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Term
020-15. In the NORM trigger mode, how are the pretrigger waveform and post trigger scan updated? |
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Definition
By the trigger and post trigger scan from the trigger position to the right. |
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Term
020-16. In the SAVE mode, what happens to the acquisition and display update in progress? |
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Definition
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Term
020-17. What types of measurements in the STORE mode are made with CURSORS controls? |
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Definition
Delta volts, delta time, one over delta time, and delay time measurements |
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Term
020-18. Which switch establishes the function of the CURSORS position control? |
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Definition
POSITION/CURS/SELECT WAVEFORM switch |
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Term
020-19. Explain how a 4K record length is shown on the display. |
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Definition
A 4-bar graph on the screen indicates which portion of the record you are viewing. A 4K record length displays 1K samples at a time. You have to look at four different screens to see the entire record length. |
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Term
020-20. In the SELECT WAVEFORM mode using the SELECT C1/C2 (cursor-select) switch, what happens when the C1/C2 switch is pressed? |
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Definition
It moves the cursor set between displayed waveforms. |
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Term
020-21. What is the purpose of the MEMORY and menu controls? |
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Definition
They control the MENU operation while the MENU is displayed, and they control the storage and display of the SAVE reference waveforms when the MENU is not displayed. |
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Term
021-1. What is the purpose of the BERTS? |
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Definition
To provide a bit error detection system that can determine the received data quality |
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Term
021-2. What type of test can the BERTS perform? |
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Definition
Bit error analysis, timing analysis, or delay measurements. Also the BERTS is a source of PCM data used to test a communications data link or a bit synchronizer output. Many BERT can generate command test patterns, telemetry PCM formats, and bit coding patterns at telemetry data rates. |
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Term
021-3. What is the purpose of the internal clock generator? |
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Definition
To provide an internal clock reference—usually selectable from the front panel |
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Term
021-4. What is the purpose of the voltage controlled oscillator, and how is it calibrated? |
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Definition
As the basic clock generator, it provides all clock phases. It is periodically frequency calibrated by a crystal-controlled oscillator in the AUTO-CAL section |
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Term
021-5. What is the purpose of the countdown section of the internal clock generator? |
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Definition
To divide the voltage controlled oscillator clock and provide a frequency equal to the bit rate selected |
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Term
021-6. What is the purpose of the digital-to-analog converter and the decode range splitter, and for what purpose does this section use the binary coded decimal information? |
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Definition
To use the binary coded decimal information to control the voltage controlled oscillator center frequency, and to control the range the countdown circuits will decode. They use the binary coded decimal information to control the voltage controlled oscillator center frequency, and to control the range the countdown circuits will decode |
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Term
021-7. What is the purpose of the pattern simulator? |
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Definition
To accept either the external or internal clock and generate either a pseudo-random noise pattern or a 48-bit pattern you program from the front panel. |
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Term
021-8. Which pattern simulator section controls the clock selector and selects either the external clock or the internal clock for processing? |
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Definition
Data/clock selects encoder |
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Term
021-9. What is the purpose of the pseudo random noise generator? |
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Definition
To receive the internal clock from the clock selector and generate a 2,047 bit long pseudo-random pattern |
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Term
021-10. What is the purpose of the pseudo random noise blanking generator, and what are the blanking periods? |
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Definition
To provide a blanking period at the start of the 2,047 bit pseudo random noise frame (under the control of the blanking selector switch). The blanking period can be 0, 32, 64, 96, or 128 bits long. |
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Term
021-11. What is the purpose of the 48-bit register and 8-bit word display? |
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Definition
To accept six 8-bit words, one word at a time, from the data entry switches and stores them in a 48-bit register |
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Term
021-12. What controls the data/clock select encoder, and what does it generate? |
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Definition
The pattern select and clock select switches; it generates a data select code and a clock select code |
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Term
021-13. Which pattern simulator section selects either pseudo random noise data, external data, or 48-bit data—depending on which data select code is received? |
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Definition
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Term
021-14. What is the purpose of the code converter? |
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Definition
To convert the NRZ-L data into the desired coding, such as NRZ-M |
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Term
021-15. What is the purpose of the clock drivers and the data drivers, and where are their outputs sent? |
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Definition
The clock drivers convert the selected clock signal to a system compatible level and a buffered TTL level, and the data drivers convert the encoded data signal to a system compatible level and a buffered TTL level. The outputs are input to the pattern synchronizer and error counter data/clock receivers block |
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Term
021-16. What is the output from the output amplifier? |
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Definition
After mixing the three input signals linearly, it provides a front panel adjustable offset and output level for a low impedance load |
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Term
021-17. What is the purpose of the pattern synchronizer and error counter? |
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Definition
To receive the selected pattern, automatically synchronizes on the pattern, and determine the bit error rate induced after transmission through the system. |
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Term
021-18. What are the inputs to the data/clock receivers? |
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Definition
Either system-compatible data or buffered TTL data from the clock drivers and the data |
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Term
021-19. Which pattern synchronizer and error counter sections combine the system compatible and TTL signals together so only one signal will be present at one time? |
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Definition
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Term
021-20. To what sections are the outputs from the data/clock receivers sent? |
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Definition
To the 48-bit synchronizer/comparator, the pseudo random noise synchronizer/comparator, the external data synchronizer/comparator, and the error rate counter and display sections. |
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Term
021-21. What is the purpose of the 48-bit synchronizer/comparator? |
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Definition
To accept the received clock and data, and synchronize on the pattern when it’s equal to the 48-bit parallel input. |
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Term
021-22. What is the purpose of the pseudo random noise pattern synchronizer/comparator? |
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Definition
To accept the received clock and data, from the data/clock receivers, and will synchronize with the pattern when it’s equal to its own 2,047 bit pseudo random noise pattern. |
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Term
021-23. What is the purpose of the external data pattern synchronizer/comparator? |
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Definition
To accept the external data, delay it under the front panel control, and compare it with the received data from the data/clock receivers. |
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Term
021-24. Where does the error/IN SYNC selector send the correct error and IN SYNC signals? |
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Definition
To the error rate counter and display |
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Term
021-25. When will the pattern synchronizer and error counter error/IN SYNC section provide an output to the front panel display, and what will interrupt this output? |
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Definition
At the end of the count cycle or when you push the reset switch. A reset pulse will interrupt this output |
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Term
022-1. What is the primary means of measuring the quality of transmitted digital information? |
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Definition
To compare the number of bits in error to the total number of bits transmitted. The ratio of the number of bits in error to total number of bits transmitted |
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Term
022-2. What is the basic quality measurement for a transmission channel? |
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Definition
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Term
022-3. What is the difference between random distribution of errors and an error rate with a clustered distribution? |
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Definition
In a random distribution, each bit is equally likely to be in error. In a clustered distribution, the errors occur in clusters. |
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Term
022-4. What are the steps in the basic bit error rate testing procedure? |
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Definition
(1) A known bit pattern, usually pseudo random, is generated at the sending end of the data channel or equipment under test, and is transmitted through the channel. (2) At the receiving end, an identical pattern is generated and synchronized with the incoming signal. (3) The received signal is compared to the locally generated pattern in the receiving equipment. (4) If any bit in the received signal is not the same as the generated bit, it is assumed the received bit is in error. (5) An error signal is generated and used to operate a counter. |
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Term
022-5. Although BERTSs use the same basic technique to count errors, how do you interpret the results and display information? |
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Definition
In many different ways. So, you must use and understand the technical manual for the particular test equipment. |
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Term
022-6. What are some significant bit error rate test equipment parameters? |
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Definition
(1) Bit rate and timing. (2) Test patterns. (3) Synchronization. (4) Interface and data coding. (5) Readouts and special features |
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Term
022-7. How can the BERTS, with internal timing for a low or intermediate bit rate range, be used to operate at higher bit rates? |
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Definition
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Term
022-8. What data circuit speed would normally use the shorter generated bit error rate test pattern lengths, and what is the data circuit bit rate? |
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Definition
Low to intermediate; 1,200 to 9,600 bps |
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Term
022-9. What data circuit speed would normally use the longer pattern lengths, and what is the data circuit bit rate? |
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Definition
Higher speed circuits; 50 kbps to 64 kbps |
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Term
022-10. What data circuit speed would normally use a 1,048,575 bit pattern length, and what is the data circuit bit rate? |
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Definition
Very high speed T–1 circuits; 1.544 Mbps |
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Term
022-11. What bit rate would you use to test a 9,600 bps data circuit? |
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Definition
A bit rate of 9,600 bps, or the closet bit rate available, to test the maximum output of the equipment |
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Term
022-12. What bit rate would be used to perform a bit error rate test on a 64 kbps data circuit? |
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Definition
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Term
022-13. What subsection in the receiving section of the BERTS must be synchronized with the received pattern from either the bit synchronizer or the distant end? |
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Definition
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Term
022-14. What is one of the major problems encountered in making bit error rate tests? |
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Definition
The detection of an “out-of-sync” condition by the test set receiver |
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Term
022-15. What should you know about synchronization in order to interpret the bit error rate test data correctly? |
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Definition
You need to know how test equipment responds to the out-of-sync condition |
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Term
022-16. What type of connectors do test sets, designed to operate with data modems, usually use? |
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Definition
25-pin connectors, usually the EIA RS–232 type |
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Term
022-17. What must you check to determine impedance and voltage levels before connecting the BERTS to the point of test? |
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Definition
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Term
022-18. What information must be available to you from the BERTS readout or special features? |
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Definition
Information to count the number of errors that occur in a specified number of transmitted bits |
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Term
023-1. Why do we test ground? |
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Definition
To verify the ground-resistance specification that the ground rod or grid must meet |
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Term
023-2. What test equipment is used to identify poor ground? |
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Definition
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Term
024-1. How many points of contacts are used in the Fall of Potential testing method? |
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Definition
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Term
024-2. What is each point of contact called in the Fall of Potential testing method? |
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Definition
The test ground, voltage probe, and current probe |
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Term
024-3. What distance represents the closest value to the theoretical true resistance measurement? |
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Definition
61.8% of the total distance. |
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Term
024-4. How is the earth stake placed in the soil? |
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Definition
In a direct line away from the earth electrode |
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Term
024-5. Which law is used to calculate the resistance of the earth electrode automatically with the earth ground tester? |
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Definition
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Term
024-6. Where are the probes placed in order to achieve the highest degree of accuracy? |
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Definition
Placed outside the sphere of influence of the ground electrode under test and the auxiliary earth |
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Term
024-7. What is the recommended ground resistance value by the NFPA and IEEE? |
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Definition
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Term
025-1. What are the primary capabilities provided by a protocol analyzer? |
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Definition
Digital network diagnostics and software development |
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Term
025-2. Explain the difference between a protocol analyzer NIC and other NICs. |
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Definition
The NIC in a protocol analyzer is configured to process all frames |
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Term
025-3. What function of the protocol analyzer excludes specific types of frames? |
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Definition
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Term
025-4. List four types of specific occurrences that can be displayed by counters. |
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Definition
Any four of the following: (1) Packets transmitted. (2) CRC errors. (3) Undersize packets. (4) Oversize packets. (5) ARP requests. (6) Collisions. (7) Bit errors. |
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Term
025-5. What menu is best used to report errors that occur at the physical layer such as bad FCS, short frames, and jabbers? |
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Definition
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Term
025-6. What kind of information does the connection statistics menu provide? |
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Definition
Connection statistics provide information concerning the bandwidth utilization and the number of connections that are related to specific nodes. |
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Term
025-7. Identify the three types of active tests that are conducted with a protocol analyzer. |
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Definition
(1) PING. (2) Trace route. (3) Traffic generator. |
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