When a FANUC robot stops and shows a code on the iPendant, the first thing is not to panic: FANUC alarms follow a clear logic and understanding their structure helps you decide whether it's something you can solve on the floor or whether you should call the service team.
How to read a FANUC alarm
The usual format is FAMILY-number (for example, SRVO-062) together with a descriptive text and a severity: from a simple warning (WARN) to alarms that pause or stop the robot for safety (PAUSE, STOP, SERVO). The family tells you which subsystem the problem comes from.
SRVO — Servo control
It's the most frequent family and the most critical. It affects motors, encoders (pulsecoder), brakes, overload, the position-retention battery and wiring. Typical examples:
- Low pulsecoder battery: a warning that the battery must be changed before losing axis position.
- Overcurrent / collision: the robot has hit an obstacle or there's a servo-amplifier problem.
- Pulsecoder not responding: encoder fault or its wiring.
Many SRVO alarms stop the robot for safety and should not be re-armed without diagnosing the cause.
SYST — System
Related to start-up, configuration and the general state of the controller. They appear, for example, after a memory loss, a board change or an incomplete configuration. They usually require reviewing the controller backup (SRAM/FROM).
MOTN and INTP — Motion and program
MOTN groups movement problems: axis limits reached, singularities, excessive speed or unreachable positions. INTP are program interpreter errors (TP/KAREL): badly defined instructions, registers out of range or invalid jumps. Many are fixed by adjusting the program or the trajectory.
What you can do and when to call a technician
Floor staff can note the exact code, check the manual and, for resettable warnings, correct the cause and re-arm. You should call a FANUC service team when:
- The alarm repeats after a reset.
- It's an axis SRVO or appears after a board change or battery loss.
- The code isn't documented or it involves opening the controller.
Frequently asked questions
What does an SRVO alarm mean?
A servo-control problem: motors, encoders, brakes, overload, battery or wiring. Some are resettable; others stop the robot and require diagnosis.
Can I reset an alarm myself?
Warnings can usually be reset from the iPendant after fixing the cause. Serious servo alarms should not be re-armed without understanding the origin.
When to call the service team?
If the alarm repeats, affects axes, appears after a board change, or isn't documented.