Practice Test Geeks(FANUC) Fuji Automatic Numerical Control Robotics Certification Practice Test
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Maintenance & Troubleshooting of CNC Robots Flashcards

7 cards from real FANUC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Maintenance & Troubleshooting of CNC Robots flashcards as text

  1. Alarm SRVO-047 (HVAL Alarm) appears on a FANUC robot. What does this indicate?

    Answer: Hardware velocity exceeded the axis speed limit

    SRVO-047 HVAL (Hardware Velocity Alarm) triggers when an axis velocity exceeds the maximum hardware speed limit, often caused by runaway servo or loose encoder coupling.

  2. When using FANUC's Dual Check Safety (DCS), a 'Position/Speed Check' violation alarm does NOT reset automatically after clearing. What must the technician do?

    Answer: Cycle power and confirm the robot is within the safe zone before resuming

    DCS safety alarms require the robot to be physically moved into a safe position and a deliberate operator action (power cycle + confirmation) before the safety system resets.

  3. A FANUC R-30iB controller shows a PRIO-155 alarm (User alarm). Where would a maintenance technician find the custom description text for this alarm?

    Answer: In the TP program UALM[ ] configuration under MENU > SETUP > Alarm

    User alarms (PRIO-155) are configured through MENU > SETUP > Alarm, where each UALM[n] entry can have a custom description string assigned by the programmer.

  4. To back up FANUC robot programs and system parameters to a USB drive, which image type preserves ALL data including mastering and calibration?

    Answer: IMAGE backup (SYSIMAGE.IMG)

    An IMAGE backup (SYSIMAGE.IMG) creates a complete bit-for-bit copy of the FROM/SRAM memory including mastering data, calibration, system variables, and all programs.

  5. A FANUC robot's cycle time has gradually increased over several months. After checking programs, what maintenance item most likely contributes to this degradation?

    Answer: Mechanical wear increasing joint friction and reducing achievable speed

    As harmonic drives and bearings wear, increased friction forces the servo system to reduce speed to stay within torque limits, gradually increasing cycle time.

  6. Which FANUC system variable should a technician check to verify the remaining battery voltage for SRAM memory backup?

    Answer: $BATT_VOLT

    $BATT_VOLT stores the current measured voltage of the controller's SRAM backup battery, allowing technicians to confirm battery health without external measurement.

  7. A FANUC CNC robot produces chatter marks on a machining workpiece only at certain path segments. The most appropriate first diagnostic step is to:

    Answer: Review the path using FANUC's Fine Motion or Servo Tuning screen to identify velocity oscillation

    Servo Tuning / Fine Motion monitoring displays velocity, torque, and positional error in real time, allowing identification of the specific motion segment causing oscillation before making hardware changes.