Fundamentals of CNC Robotics Operation Flashcards

What is the FANUC macro instruction $SHELL_CMD used for in advanced programming?

Answer: Executing operating system shell commands from within a Karel program

$SHELL_CMD allows Karel programs to invoke system-level OS commands on the robot controller.

Which joint configuration setting prevents a FANUC robot from flipping its wrist during continuous linear motion?

Answer: SINGULARITY AVOIDANCE enable in motion setup

Enabling singularity avoidance allows the controller to deviate slightly from the programmed path to prevent J5 near-zero wrist flip.

On the FANUC R-30iB+ controller, what does the STATUS indicator light flashing amber (yellow) signify?

Answer: A non-fatal alarm is active but the robot can still run

A flashing amber STATUS light indicates a warning-level alarm that does not prevent motion but should be investigated.

What is the correct sequence to perform a cold start on a FANUC robot controller?

Answer: Cycle power while holding PREV + NEXT on the teach pendant

Holding PREV + NEXT during controller power-up forces a controlled cold start that clears runtime state.

Which FANUC feature allows a robot program to be automatically selected and started by an external PLC signal?

Answer: Program Select (RSR or PNS)

RSR (Robot Service Request) and PNS (Program Number Select) allow external devices to select and start TP programs via I/O.

In FANUC arc welding applications, what does the 'Arc Start Retry' function do?

Answer: Attempts to re-ignite the welding arc a set number of times before faulting

Arc Start Retry re-attempts arc ignition up to a configured maximum count before triggering an alarm.

What does the FANUC Zero Torque Control mode enable during robot operation?

Answer: Allows the robot arm to be freely back-driven by hand with minimal resistance

Zero Torque Control (also called drag-teach or gravity compensation mode) lets an operator manually guide the robot with minimal force.