What the SRVO-050 alarm means

The collision detection function judged that the robot hit something. Servo power is cut immediately to limit damage. This is a routine repair in our workshop for FANUC R-30iA / R-30iB / R-30iB Plus systems, and we normally pin it down during the first site check.

Most common causes

  • Actual collision with fixture, part, or person
  • False trigger from wrong payload settings
  • False trigger from aggressive acceleration with heavy tooling
  • Mechanical looseness causing vibration spikes
Field note: Begin with the first item in the list; it has a far higher on-machine occurrence rate than the others.

Step-by-step field fix

  1. Inspect the tool, part, and fixture for collision damage before anything else
  2. Jog away from the collision point slowly in low speed
  3. Verify payload setting - wrong payload is the #1 cause of false triggers
  4. If genuine false positives continue, review collision guard sensitivity settings (do not simply disable the function)
Safety first: For FANUC srvo-050, servo circuits are live and motor shafts and reducers rotate: measuring current waveforms or winding resistance means contact with live or moving parts. The self-serviceable action is Inspect the tool, part, and fixture for collision damage before anything else; anything past that falls under live servo circuits and rotating parts and needs a certified engineer.

How we diagnose servo alarms on site

FANUC srvo-050 belongs to the servo & drive family. On FANUC srvo-050 the failing stage is alpha-i / beta-i servo amplifiers with PSM supply modules and SVM servo modules (SPM where spindles fit) on the R-30iB Plus / R-30iB Mate Plus / R-30iA - the servo closed loop: current/velocity/position loop misbehaviour, motor-drive matching and load identification. We start reading FANUC srvo-050 at the iPendant ALARM screen (SRVO / MOTN / SYST / INTF prefixes) together with the amplifier's 7-segment status code.

The chain involved in FANUC srvo-050 runs: target -> position loop -> velocity loop -> current loop -> power output -> motor -> feedback -> loop compare.

Actual collision with fixture, part, or person on FANUC srvo-050 needs two causes separated first: A servo motor whose brake never fully opens runs overloaded and reports overcurrent or overload - it looks like a dead drive. Insufficient coil supply, a sticking lining or a wrong gap all produce this running-on-brake condition. The other case is turn-to-turn winding shorts: one phase reads high current and the motor runs hot. We measure brake coil supply and actuation current first, then winding resistance balance across the three phases; only when both are wrong do we talk about replacing the motor.

Field notes on this page cover FANUC srvo-050 (CLALM - Collision Detect Alarm); written by the Henghuan repair team, updated 2026-10-01.

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Related Servo & Drive alarms

SRVO-021 — SRDY Off (Group / Axis) SRVO-023 — Stop Error Excess (Group / Axis) SRVO-024 — Move Error Excess (Group / Axis) SRVO-043 — DCAL Alarm - Discharge Alarm SRVO-044 — HVAL Alarm - High Voltage SRVO-045 — HCAL Alarm - High Current
Same family: this code belongs to the Servo & drive alarms family - the page collects all Servo & drive-family codes we have handled, with the common inspection order and spares.
Other brands: see our KUKA, ABB, Yaskawa and Universal Robots field-fix libraries — or the full 10-brand hub.

Frequently asked questions

QWhat does the FANUC srvo-050 alarm mean?

The collision detection function judged that the robot hit something. Servo power is cut immediately to limit damage. This is a routine repair in our workshop for FANUC R-30iA / R-30iB / R-30iB Plus systems, and we normally pin it down during the first site check. FANUC srvo-050 sits in the servo & drive family; on our work orders the highest-frequency trigger for this code is "Actual collision with fixture, part, or person".

QCan I clear a FANUC srvo-050 alarm myself?

Whether FANUC srvo-050 clears on its own depends on the outcome of "Inspect the tool, part, and fixture for collision damage before anything else". Finish the flow with "If genuine false positives continue, review collision guard sensitivity settings (do not simply disable the function)" to confirm FANUC srvo-050 - do not skip it. If that step is clean, the second most frequent cause on FANUC srvo-050 is "False trigger from wrong payload settings". If FANUC srvo-050 returns after two clears, or the checks point at Actual collision with fixture, part, or person, stop the cell and call a professional robot repair engineer.

QFor servo alarms like FANUC srvo-050, how do you tell motor from drive?

The commonest causes we see on FANUC srvo-050 are "Actual collision with fixture, part, or person, False trigger from wrong payload settings, False trigger from aggressive acceleration with heavy tooling", so we stock the van against those. For FANUC srvo-050 specifically, we bring the scope and meter; motors and drives are stocked by type, and most cases are measured before parts are ordered. For FANUC srvo-050, on servo alarms we specifically avoid misjudgement: waveform first, parts second, so customers skip needless swaps. Before we roll, tell us what FANUC srvo-050 shows on the iPendant ALARM screen (SRVO / MOTN / SYST / INTF prefixes) together with the amplifier's 7-segment status code and what the machine was doing - phone or video triage is free.

This page on FANUC srvo-050 was written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your FANUC documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by FANUC.