CDC Questions

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CDC Questions
2010-05-02 23:34:06

CDC Questions
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  1. What's the purpose of the mops?
    Provide DC power for the SIM.
  2. How does VR1-48 act to regulate MOPS output?
    The pass element inside the VR acts as an electronic variable resistor that drops the input voltage to the required output level.
  3. Why does the power switch driver CCA disable the sense relay drivers prior to disabling the power relay drivers?
    Ensures power isn't applied to the STA through power sense cca.
  4. What CCA provides local/remote sensing paths?
    Power sense switch CCA.
  5. Why is remote sensing preferable?
    For increased accuracy.
  6. How is the power sense switch used during self test?
    Routes sense and voltage monitor signals to the 4 wire bus.
  7. What conditions does the monitor CCA monitor?
    Backplane voltages, regulator flags, flags from the ICA, external power interlock, LRU blower temp.
  8. What's the purpose of the probe panel in the SIM?
    For direct access to the test station.
  9. When is the biphase digital format used?
    When transmitting Manchester II in the DSS and certain B/B LRU's
  10. What is PWM?
    A time encoded data format.
  11. How did the triple serial CCA's get their name?
    They generate RZ and NRZ data to be sent to the UUT on 3 different channels
  12. What's the source of the parallel timing bus signals generated in the clock I/F card?
    Station trigger bus, RF signal from the UUT, RF oscillators
  13. How are resistance measurements made by the test station?
    By applying known current to an unknown resistance and measuring the voltage developed across it
  14. If you're measuring a 6-MHz AC signal, which measurement CCA is applied?
    HF measurement CCA
  15. How are pulsed DC voltages handled by the MSS?
    In the same manner as AC measurements.
  16. Describe the process for making time interval measurements.
    One input pulse is used to start the counting of a known freq. and the other input to stop.
  17. Describe the operation of the counter I/F CCA during a rise time measurement.
    The counter I/F is programmed to start pulse when the incoming signal reaches 10% and to stop at 90%
  18. What's the purpose of the 10 MHz reference CCA?
    To provide an accurate and stable freq. and time standard for the time base AC reference CCA & other circuitry in the test station.
  19. What are the 3 output ranges of DC REF?
    (All plus or minus) 10 VFS, 2 VFS, 100 VFS
  20. What is the function of the GPS jumper CCA?
    Provides wraparound between J! connector pins and feedthru from connector J1 to connector P1
  21. Describe the STA.
    Feedthru device used to route stimulus signals out of the station via the ICA and back into the measurement subsystem.
  22. Describe the construction of the STA.
    Made of conventional coax point to point wiring and some passive components.
  23. What is the 1553?
    A DOD standard used to link avionics & test station systems
  24. Describe the data words that are transmitted on a 1553 bus.
    Words are composed of 20 bits. The first 3 are sync pulse, then there are 16 bits of info, & on bit of parity.
  25. What function does the TMA set perform?
    Converts parallel data over IEEE-488 bus to a serial format that can be used by CCA's
  26. In what format are LRU programs stored on the hard drive?
    In interpretive code
  27. What process is used for transferring data from the computer to a TMA set?
    Program data converted to CIIL by computer I/O section & output to the TMA set over the IEEE-488 bus
  28. What are the benefits of the MATE concept?
    By using CIIL to communicate with each module, station hardware can be upgraded with very little software modification.
  29. What's the purpose of CR 10-12?
    Transient protection
  30. The DAAE can be used with which stations?
    DIG or DAV
  31. What DC voltages are applied by the power dist. group?
    5VDC 12VDC + or - 15VDC
  32. Which DIFARFAD component contains the 1553 bus module that tests the 1553 bus connections of the UUT?
    HP Versa modulo europa extension for instruments mainframe.
  33. on what freq. range does JTIDS operate?
  34. How does the ARC-190 generate the frequencies needed?
    They are derived from a temperature compensated oscillator.
  35. What's the function of the ACU FTG?
    Emulates the ACU and simulates data sent to the CIU
  36. What does the ATU FTG simulate?
    Complex radar signatures to test the ATU and monitors the response of the ATU to these stimuli
  37. What components make up the TAG?
    DAAE ITA, IATE ITA, STA, and the self test cables
  38. What's the purpose of the cable termination list?
    To tabularize the connections of all DAAE interdrawer cables
  39. What test verbs are used with the DAAE?
  40. Which test verb initiates all necessary parameters?
  41. What noun modifier identifies the UUT?
    LRU ID
  42. What types of video can the monitor assy. display?
    Raster, stroke, and time shared info.
  43. How and where is airflow monitored in the V/P module?
    At the output of the rack blower motor.
  44. How and where is temp monitored in the V/P module?
    2 switches at the top of the cabinet
  45. What's the purpose of the 5.6KHz power supply?
    For testing the system integration panel, generator controller LRU, and SPS
  46. What video characteristics can be measured by the photometric test stand?
    Luminance, size, and position
  47. What command and types of data are used to measure the contrast ratio?
  48. What is returned by the MEASURE LUM-SIZE command?
    Size, X position, Y position
  49. What types of displays are generated with the APPLY, VIDEO, RASTER command?
    Shaded items
  50. Waht types of displays are generated with the APPLY, VIDEO, STROKE-VIDEO command?
    Line, star, or cross
  51. What three ATLAS commands are used to program the 5.6 KHz power supply?
    APPLY, REMOVE, or SETUP, followed by AC signal
  52. Since these commands are used for all AC power supplies, how does the station know that you are programming the 5.6 KHz module?
    The resource codes in the syntax tell the station to program the 5.6 KHz module.
  53. What 3 characteristics of the AC signal are programmable?
    Voltage, current and phase angle
  54. How is AC power applied to the 8 DC power supplies?
    Relays K1-K8
  55. What signal is applied to the DC power supplies to make automatic adjustments to the output voltage?
    Local remote sense
  56. What is the purpose of the sense lines used by the DC power supplies?
    Monitor output voltage and to provide feedback to the individual power supply voltage regulators
  57. Describe the difference between local and remote sensing.
    Remote takes a sample at the output. Local takes it's sample at the DC power switching assy.
  58. What type of power is required to energize the RF module LRU DC power supply assy's?
    2 phases of 120/208 VAC 50/60Hz
  59. How does the station computer select the power supply outlet to be switched to the ICA?
    SIM power switch driver CCA energizes the appropriate power switching relays
  60. When is and ITA interlock driver signal present?
    When an ITA/STA is installed
  61. Why are the DC power supply sense signals routed to the 4 wire bus?
    Makes the power supply outlets available to the station for diag.
  62. What type of freq. stimulus does the RF module provide?
    CW, AM, FM, PAM
  63. Which components provide stimulus to the LRU directly?
    PNA & MSC
  64. What components provide stimulus to the RF module?
  65. Which RF synthesizer is connected to unswitched AC power? Why?
    3A1A4. To maintain a constant temp. for is it's oscillator crystal
  66. Describe the output characteristics of the RF synthesizers in the RF module.
    10MHz-18GHz and -110 - 10dbm
  67. Which synthesizer provides a PM signal that the MSC converts to a biphase signal?
  68. What is the source of the drive signals used to produce PM in the RF synthesizers?
    STB, 10 MHz ref. or STG from the SIM
  69. What drive signals are used to produce AM and FM in the RF synthesizers?
    AFG or AC ref
  70. Which synthesizer outputs PAM, and how is this signal produced?
    3A1A4. AM and PM simultaneously.
  71. What type of measurements can the MSC make?
    Frequency, pulsewidth, DC voltage, PAM measurement of demodulated signals.
  72. What are the ranges of the 3 power sensors?
    848A = -70 to -20; 8481A = -20 to 10; 8481H = 10 to 35
  73. Frequency range of the specan?
    100Hz - 22GHz
  74. What is the sequence of events that occur when you use the specan to measure signal characteristics?
    Commands are sent from the MSC to the specan and then back to the station computer.
  75. When can you use a SETUP command to program a fixed DC power supply?
    To modify an APPLY statement
  76. How do the VERIFY and MEASURE commands differ?
    They're the same except in the MEASURE , the "execution field" is omitted
  77. What RF measurement command displays the results on the measurement on the CRT?
  78. Where are the results of the READ command stored?
    System variable "measurements"
  79. How are wire wrap programs documented?
    As wire connection lists.
  80. What does the signal name directory list provide?
    A cross reference between the signal number and the signal name.
  81. When does the alarm circuit of the OCC activate?
    When on of the temp flow switches open
  82. What provides ground for the motor control circuit?
    A temp switch at the a4 hydraulic pump
  83. What are the hydraulic circuits made up of?
    Flow meter, flow switch, and pressure guage
  84. What does the unused hydraulic circuit do when only one LRU is being cooled?
    Bypass using the jumper hose assy.
  85. What component of the radiation monitor houses the detecting element?
  86. What component provides a visual indication of signal strength?
    Power meter
  87. What TO should you refer to for ESD information?