CDC Volume 2 Self Test Questions

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CDC Volume 2 Self Test Questions
2010-12-27 15:42:38
CDC Volume Two

CDC 2A051S Self Test Question
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  1. Define “Triboelectric” effect.
    The production of an electrostatic charge by friction.
  2. How does higher humidity reduce the ESD danger?
    It keeps surfaces moist, thereby increasing the conductivity of the surfaces.
  3. What is the desirable humidity level for ESD protective areas?
    40% - 60%
  4. How does mounting a component on a circuit board affect the ESD susceptibility?
    Doesn't reduce susceptibility.
  5. Which ESDS items must be handled at an approved, static safeguarded workstation?
  6. Why do reparable items require ESD protective packaging?
    So no further ESD damage is done to the remaining operating parts of the item being handled.
  7. Define the term static dissipative material.
    Provides a static drain fast enough to remove the static charge quickly before any damage is done and slow enough now to produce a damaging discharge current.
  8. Explain what could occur if you sprayed an antistat an a circuit board and why.
    Circuit malfunctions could occur because of leakage path formed by the antistat.
  9. what are the three principal components of any ESD control workstation?
    • 1. Static dissipative work surface
    • 2. Personnel wrist strap (cuff and cord)
    • 3. CPGS
  10. Why should you roll up your long shirt sleeves when working at an ESD control workstation?
    This reduces the changes of tribelectric charges developing
  11. What can you use in an AC outlet to ground ESD control workstation?
    The outlet mounting screws.
  12. can you wear a wrist strap while working on energized equipment?
  13. Describe the proper wear of a personnel wrist strap.
    The cuff is worn snug to the wrist, with no clothing between the cuff and your skin.
  14. how often must wrist straps be checked to see if they are functional?
  15. what can you do to improve wrist strap conductivity if you have dry skin?
    Use hand or moisturizing creams.
  16. what is used to test the integrity of the entire wrist strap system?
    Wrist strap tester.
  17. when must you wear static dissipative garments?
    When handling supersensitive devices.
  18. what are the units of force when you're developing torque?
    Onces, pounds, grams, and kilograms.
  19. what are the units of distance when you're developing torque?
    inches, feet, millimeters, and meters.
  20. how are the magnitudes of torque most commonly expressed?
    inch-pounds and foot-pounds
  21. using the torque conversion table found in figure 1-12, convert 3 foot-pounds to an equivalent torque in inch-pounds.
    36 inch-pounds
  22. describe the four types (I,II,III, and IV) of torque wrenches.
  23. What's the purpose of a balanced torquing sequence?
    to prevent warping the assembly being torqued
  24. when are torque requirements met?
    when the minimum torque value is reached.
  25. under what circumstances should you use a torque wrench to break loose a bolt?
  26. what should you do if you have over-torqued a bolt?
    Loosen the bolt and start again.
  27. what fastening device is normally associated with prevailing torque?
    self-locking nuts and screws.
  28. when must you compensate for prevailing torque?
    when required by the technical data
  29. you're preparing to torque a nut to 120-inch-pounds using an extension. what information do you need to find the torque setting?
    the length of the torque wrench and effective length (the length of the torque wrench plus its extension)
  30. compute the modified torque value for 120-inch-pounds of recommended torque using a 12-inch torque wrench with an 8-inch extension.
    72 inch-pounds.
  31. what must you do if you drop a calibrated torque wrench?
    have the wrench re-calibrated before it's used again.
  32. where can you find guidelines for tool management?
    AFI 21-101 and local supplements or policies.
  33. what is TAS?
    An automated tool accountability system
  34. what information can you get from TAS?
    The status for a CTK and when a CTK is due for a periodic inspection.
  35. what do you use to inventory a CTK?
    • A printout of the MIL* from TAS
    • *Master Inventory List
  36. where do you document that a tool was removed from a CTK?
    in TAS and on all copies of the MIL
  37. what is the purpose of the EID?
    To identify the base, unit, shop, and CTK that a tool belongs to.
  38. Describe amplitude modulation.
    The amplitude of the carrier is varied to represent some sort of information.
  39. What happens in mixing?
    two new frequencies are produced: The upper sidebands and lower side bands.
  40. what is process of removing the intelligence from the carrier?
  41. when is it more efficient to use pule amplitude modulation?
    when using a carrier greater then 1,000 MHz
  42. what frequency bands are used with pulse amplitude modulation?
    super high and extremely high modulation
  43. for what is directional coupler used
    used to sample the input signal qith out the need for moving parts or adjustments.
  44. what are the outputs of a mixer?
    2 input, 1 sum, 1 difference
  45. How does a power divider affect the power and frequency characteristics of a signal that passes through it?
    the power is cut in half, but the frequency stays the same.
  46. what is the purpose of an isolator?
    normally used to isolate two separate circuits or prevent any feedback
  47. what is the difference between a fix attenuator and a programmable attenuator?
    fixed attenuator provides constant attenuation; programmable attenuator provides variable attenuation.
  48. what are at least three units that can be displayed by the power meeter?
    Watts, Milli-watts, Micro-watts, Nano-watts, dB, and dB (REL)
  49. how do you use the relative power measurement mode for frequency response testing?
    You set the dB(REF) for the transmitter under test, and then monitor and changes in power at different frequencies or settings.
  50. In general terms, what does a power sensor do?
    Changes energy from one form into another form.
  51. what are some of the older power sensors?
    bolometers, calorimeters, thermistors, and thermocouples.
  52. what are some of the advantages of a diode detector over a thermistor mount?
    higher sensitivity, reduces noise, less frequency drift, and lower SWR.
  53. How much more efficient is a detecting diode than a thermistor?
    3,000 times.
  54. what device determines the power measurement range of a power meter?
    The power sensor.
  55. what must you do before you can use the power meter/power sensor system?
    Marry (calibrate) them together.
  56. why should you not twist a power sensor when installing it?
    You may cause major damage to the power sensor's internal circuits.
  57. What is the basic RF power measurement?
    Average power.
  58. what must you do before turning ON the power meter?
    Make sure it's set to match the line voltage you're using.
  59. after you've turned the power meter on, what's the first task you must do?
    Zero the power sensor.
  60. How much RF input is allowed when zeroing the power sensor?
  61. What happens when you press he dB (REF) switch a second time?
    Enters a new reference level.
  62. When taking measurements of a signal, should you make the signal as high and wide as possible, or as short and narrow as possible?
    As high and wide as possible
  63. At what percentage amplitude points do you measure the rise time of a pulse?
    between the 10% and 90% amplitude points on the leading edge of the pulse.
  64. How much faster should the vertical system of your scope be than the rise time of the applied signal?
    2-5 times faster
  65. what is the formula for converting time to frequency?
    F = 1/T
  66. What is the frequency range of the typical spectrum analyzer?
    9kHz to 26.5GHz
  67. What must be done to the spectrum analyzer before making measurements?
    it must be calibrated.
  68. What piece of test equipment is used to self-calibrate RF devices within system or test station?
    the SNA
  69. Generally speaking, what does a counter do?
    It accumulates, from an applied signal, input pulses in binary form, and then converts them to decimal form for a digital readout
  70. what are the basic measurement functions of the universal counter?
    frequency, period, time, totalize, and volts
  71. what the most accurate, convenient, and flexible instruments available for making frequency and time interval measurement
    electronic frequency counters.
  72. what are the five operating modes of the pulse generator?
    Normal, Trigger, Gate, External width, and External burst
  73. what determines the number of pulses output in B.BUR mode?
    by parameter values set by the range/vernier rocker switch.
  74. ow many control modes can be selected?
  75. What sweeper keys are used to select specific frequent and power levels?
  76. what key selects the special functions
  77. what frequency must the start frequency be, in comparison with the stop frequency?
    Must be 100MHz lower
  78. what does the CF key select
    Selects the center frequency
  79. what does the (Delta)F key select?
    Frequency span for the center frequency.
  80. What are the three basic requirements of facility power?
    be at proper voltage, at the required amperage, and at the necessary frequencies
  81. what is the input voltage requirements of a test station?
    115 VAC
  82. what are the input frequency requirements of a test station?
    60Hz and 400Hz
  83. what two components are required to produce voltage outputs from an AC power supply?
    transformers and filters
  84. DC power supplies use what three types of rectifiers?
    1. Half-wave 2. Full-wave 3. Bridge
  85. what is the purpose of the 400Hz power to a test station
    provide all voltages for a TRU and LRU
  86. what is a stimulus
    anything thats generated for application to a TRU or UUT
  87. what items are considered stimulus
    Cooling air, AC voltage, DC voltage, RF signals, AF signals, Logic signals
  88. what are the possible output signals of a waveform generator?
    sine wave, triangular wave, square wave, DC voltage level.
  89. what is the frequency range of an AF generator?
    20-20,000 cycles per second
  90. what is the purpose of a measurement device
    measurement, monitor, or evaluate responses from a UUT
  91. what type of signals do digital multimeter measure
    AC voltage, DC voltage, and resistance
  92. what is frequency counter period measurement
    the time from one input pulse or signal to the next - measured in seconds
  93. what is used to measure the power level of RF signals
    Power meters
  94. what is considered the most versatile measurement instrument capable of a visual disply
  95. what primary function does switching provide
    a means of interconnecting test station resources with the UUT
  96. test station switching has what two classifications?
    stimulus and measurement
  97. what are the three major considerations in designing proper switching in a test station?
    1. selection of stimulus 2. routing of signals throughout the test station and to the UUT 3. Routing of UUT responses to a selected measurement device
  98. what controls the switching in a computerized test station
    program execution of specific test statements
  99. what is considered to be the most important test station function
  100. what is a major factor in determining the type of control device a test station will have?
    speed of the UUT operation
  101. what is a computer program
    a set of instructions that allow a digital computer to process data.
  102. instruction identified by a code number describes what type of computer program
  103. what is commonly used to represent the digits in computer language?
    volts and current
  104. IEEE-488: how many devices may be connected to one bus
    up to 15
  105. list the four catergories in which the IEEE-488 bus lines are grouped.
    Data lines, handshake lines, Bus management lines, ground lines,
  106. list three handshake lines
  107. which handshake lines is asserted by a listener to indicate it is not yet ready for the next data or control byte?
  108. list the five bus management lines
    attention, end of identity, interface clear, remote enable, service request
  109. describe a service request line
    the SRQ is like an interrupt; it may be asserted by any device. the SRQ is released when polled by the controller.
  110. when can the NDAC handshake line go high?
    when the slowest listener has accepted the data byte.
  111. what is multiplexing
    the process of transmitting information from several sources through one system with different signals staggered in time to form composite pulse train
  112. what is the biggest advantage of multiplexing
    saving in size and weight of avionics units and the interconnecting wiring between them
  113. how many types of avionic terminals are there, and list them
    three. Buss controller, monitor, remote terminal
  114. what is the purpose of the bus controller?
    coordinating the flow of information on the data bus
  115. what is the purpose of an RT on an avionics data bus?
    any terminal not acting as the bus controller or bus monitor
  116. what are the four elements making up the MIL-STD-1553 data bus system?
    bus controller, bus monitor, remote terminal, the data bus itself
  117. what does the bus controller do when it detects an error
    ertransmit the command to recover from the error
  118. an RT must be able to handle protocol errors. what's a protocol error?
    incoming command and data that's electronically correct, but the message is illegal by the protocol established within the MIL-STD-1553
  119. what element of the data bus is ca[able of assuming the task of bus controller in the event the bus controller fails?
    a remote terminal
  120. what element of a data bus is not needed for normal operation and is not normally included in avionic data bus systems?
    remote terminal
  121. what element of a data bus id not needed for normal operation and is not normally included in avionic data bus systems?
    bus monitor
  122. when are transformers-coupled stubs used in the 1553 data bus
    when stub length is over 20ft long
  123. which type of stub coupling is better, transformer-coupled or directed-coupled
  124. what types of digital information or words are used on a data bus
    command, status, and data
  125. describe the common structure of command, data and data words
    each word type is 20 bit-periods in length. each word has a command sync charter, which is three bit-periods in length, followed by 16 information bits and, finally, 1 parity bit
  126. in the SAM feield of a command work, to what does "subadderss" refer
    to a function or an area within the RT to which the command is being directed.
  127. which elements of the data bus transmit data words?
    bus controller or an RT
  128. During a controller-to-RT transfer, what does the RT do after receiving command and data words form the bus controller?
    the receiving RT validates the incoming command and data words. If the message is valid, the RT responds with a status word, acknowledging receipt of the command and data.
  129. In an RT-to-RT transfer, what does the receiving RT do upon completion of the transfer?
    once the receiving remote terminal has received and validated the data words, it responds with its own status word indicating that successful completion of the transfer
  130. in mode command without a data word, what does the word count field contain?
    mode code for the command to be implemented
  131. for what does the abbreviation VXI stand?
    VME extension for instrumentation
  132. what factors largely drove industry to develop the VXI standard?
    industry demand for reduction in physical size, tighter time and synchronization between multiple instruments, and faster transfer rates
  133. List four benefits that VXI brings to instrumentation user.
    1. open, multi vendor standards that maximize flexibility and minimize obsolescence 2. increase system throughput reduces test time and/or increases capability 3. more precise timing and synchronization improve measurements capability 4. modular, rugged design improves reliability, increases MTBF, and decreases MTTR
  134. how can the logical address of a VXI device be set?
    manually or automatically
  135. what are the two classifications of VXI devices with respect to register capabilities
    register based and message based
  136. what are VXI message-based devices required to use in order to communicate in a standard way?
    word serial protocol
  137. what is defined by the VXI bus and used to construct a hierarchical system of VXI devices?
    command-servant communication protocol
  138. how does a message-based device communicate with it's commander
    word serial protocol
  139. how does a register-based device communicate with its commander
    device-specific register manipulation
  140. the VXI bus specifies how many modules?
  141. what are the larger size modules (C and D) for?
    high performance instruments
  142. within the VXI mainframe, what provides the communication path between the other modules in the mainframe and the host computer
  143. a VXI controller may contain an embedded computer and/or with what can it communicate?
    external computer
  144. what are the three methods used to control a VXI system?
    1. VXI mainframe linked to an external controller via the GPIB 2. VXI-based embedded computer 3. A high-speed MXI bus link from an external computer.
  145. how does the MXI bus interconnect devices?
    flexible cabling scheme
  146. what classifies a device as an MXI device?
    with MXI interface board installed
  147. how does the MXI bus tightly couple multiple devices?
    mapping together portions of their individual address space
  148. How do MXI devices directly access each other's resources
    performing simple read and writes to appropriate locations
  149. at what rate does does MXI bus data transfer?
    8,16,and 32 bit
  150. what is the maximum data transfer rate for the MXI bus?
    20 Mbytes/second
  151. describe the MXI bus point-to-point cable
    has a single connector on each end
  152. Describe a multidrop cable
    sing connector on one end and two connectors on the other end
  153. an MXI bus cable is similar to what other type of cable
  154. The MXI bus requires the first and last devices in a daisy chain to have what?
    termination network
  155. Describe block data rate.
    the rate at which you can move a large block of data to or from memory on an ideal VXI device using back-to-back VXI transfers.
  156. what affects the actual data transfer rate that cab be achieved?
    the read/write access time of your remote system and length of MXI cable
  157. Why are system procedures to be used only by programmers who have intimate knowledge of the test station hardware, control system, and software system?
    improper usage may cause improper connection, catastrophic damage to the test station, damage to the UUT, incorrect or ambiguous test results, incorrect resources status information
  158. how d ATLAS system procedures allow low-level control of the test hardware?
    by permitting direct output of hardware control signals on the station internal control buses.
  159. a standard ATLAS program structure consists of what?
    preamble and procedural structure
  160. what is always the first section of an ATLAS program?
    The preamble
  161. list the three functional classes of ATLAS statements that are commonly used in the preamble structure to define the words and phrases of the language?
    common, declare, and define
  162. how are ATLAS variables identified
    By a label or name using single quotes, or dinks
  163. what ATLAS statement number normally begins the procedural section and is normally the first executed statement during UUT testing?
  164. in statement syntax, how is the provision for one-time looking back distinguished
    by the dot on the bypass line
  165. name six fields that can make up each ATLAS statement
    Flag field, statement number, verb, field separator, variable, and statement terminator
  166. what are the two basic fields in an ATLAS statement?
    Fixed and variable
  167. what does the variable field element of an ATLAS statement accomplish?
    allows the programmer to specify in great detail exactly what is applied or how the timing of a signal is set up.
  168. what are the types of statements that you don't need the rest of the test station to properly execute
  169. which statments are used to set aside computer memory to hold the contents of variables
    Data declarations
  170. what do calculate/compare statements do?
    test and modify the values of variable and system flags
  171. COMPARE statements set or reset which system flags
    GO, NO-GO, HI, and LO
  172. What is the purpose of decision/branching statements
    to alter the normal sequence of program flow.
  173. How does a WHILE-END WHILE statements differ from a FOR-END FOR
    the looping in the WHILE statement continues until the condition specified is satisfied
  174. what function do test statements perform
    they cause the test station hardware to perform specific tasks
  175. what are the three categories of test statements
    analog measurements, analog stimulus, and digital testing
  176. For what are analog stimulus statements used
    to make the test station generate a signal that is analog in nature
  177. what are the six basic verbs used in a digital testing.
  178. what is the major difference between ATLAS statements and protocol?
    The protocol doesn't have to be converted to machine code like on ATLAS statement does before the computer runs it
  179. is substitute equipment allowed to be used to perform a PATEC calibration
    Yes, provided they meet required functions, ranges and accuracies
  180. What controls the automatic station calibration
    ATE computer
  181. What does the SECAL program control in the ATE computer during calibration
    support equipment operation during calibration
  182. what are the three main parts of the uncertainty factor
    1. gross errors 2. system errors 3. random errors
  183. list three types of systematic errors
    Instrumental, Environmental, and Observational
  184. which type of systematic errors result from external conditions, such as temperature, vibration, and magnetic fields
  185. if a meter has been calibrated by PMEL and has a calibration sticker on it, where should you be about to trace the calibration standard to?
    the NIST
  186. what ration ensures traceability
  187. can you use a meter with an accuracy of .03% to align a meter with a tolerance of .02%
  188. what calibration sticker is normally used to indicate ATE has been calibrated?
    AFTO form 108
  189. What does the SPECIAL block of AFTO form 99 identify
    limitations placed on the piece of TMDE
  190. when is AFTO form 256used on a piece of equipment
    when an item is identified as needing no calibration
  191. why must the PATEC remain plugged in to an acceptable power source
    to maintain the Rubidium frequency timing standard
  192. what happens if the PATEC is unplugged from its primary power source
    its battery back up maintains calibration standard for a limited period of time
  193. What is PYM-1 CAPRE system
    a common reprogramming device that can be utilized by many systems on many airframes
  194. what power source(s) is/are available to the CAPRE
    AC adapter and an internal, rechargeable battery
  195. what operating system runs the CAPRE computer?
    Microsoft Windows
  196. What is the purpose of the CCM
    convert files from the SFF to whatever format is required to communicate and transfer data
  197. what DOD network may be used to transfer classified data
  198. how often does the CAPRE rewuire visual inspection?