FANUC Maintenance & Troubleshooting of CNC Robots 4

Question 1

A FANUC robot joint fails to move and displays SRVO-006 (Hand Broken). In a typical configuration, what triggers this alarm?

Accepted Answer

An end-of-arm tooling overload signal or broken-tool detection I/O input is active

Answer

SRVO-006 is triggered by an active signal on the configured hand-broken detection I/O input, which is typically wired to a tool crash sensor or pneumatic pressure switch.

Question 2

When performing FANUC joint mastering using the Master/Cal fixture method, the robot joints must be positioned at:

Accepted Answer

The zero-degree reference position defined by the mastering fixture marks

Answer

Fixture mastering requires aligning each joint to its physical zero-degree mark (witness line or tooling hole) so the pulse coder reference matches the mechanical zero position.

Question 3

During FANUC controller maintenance, the technician notices the SRAM battery alarm is active. What is the immediate risk if power is cycled without replacing the battery first?

Accepted Answer

All SRAM-stored data (programs, mastering, system variables) will be lost

Answer

SRAM is volatile memory backed only by the controller battery; if power is cycled with a dead battery, all programs, mastering data, and system variables stored in SRAM are permanently erased.

Question 4

A FANUC robot axis moves in the wrong direction compared to taught positions after a motor replacement. The technician should:

Accepted Answer

Check and correct the axis direction parameter ($DIR_PARAM) or perform re-mastering

Answer

Wrong-direction movement after motor replacement typically indicates the replacement motor has a different encoder phase or the axis direction parameter needs to be verified and corrected, followed by re-mastering.

Question 5

In FANUC CNC robotics, what is the purpose of the 'Torque Limit' instruction (TL[n]) in a TP program?

Accepted Answer

It limits the servo torque to protect workpieces or tooling during specific motion segments

Answer

TL[n] temporarily reduces the servo torque output to a percentage of maximum, used to prevent workpiece damage, detect obstructions, or protect tooling during force-sensitive operations.

(FANUC) Fuji Automatic Numerical Control Robotics Certification Practice Test

(FANUC) Fuji Automatic Numerical Control Robotics Certification Practice Test

FANUC Maintenance & Troubleshooting of CNC Robots 4