What causes SRVO-050?

Actual collision or external force - including tool stuck to the work ('tip stick'). Wrong payload settings (mass, center of gravity, inertia) - the most common false trigger. Aggressive motion: ACC over 100, sharp CNT reversals, linear moves near singularity. Cold plant, stiff grease - friction spikes after weekends and cold nights. Brake dragging or low supply voltage. Mechanical wear: reducer, balancer (listen for noise), or deeper hardware faults.

How do I fix SRVO-050?

Inspect for a real collision first. To recover: hold SHIFT+RESET, release only RESET, keep SHIFT held and jog the axis AWAY from the obstruction. Verify the payload schedule matches the actual tool and part; run payload ID if available. If tied to one aggressive move, soften it (reduce ACC, smooth the reversal, reroute from singularity). The disturbance threshold is visible at STATUS > Axis > DISTURB - resist the urge to raise it to silence the alarm; that removes a protection layer. After cold or idle periods, warm the robot at low speed before full-rate production. One axis triggering repeatedly with clean payload data earns a mechanical inspection: brake release, reducer, balancer.

SRVO-050

SRVO-050: Collision Detect alarm

The servo software estimated a disturbance torque too large to be normal motion and concluded the robot hit something.

What it means

The servo software estimated a disturbance torque too large to be normal motion and concluded the robot hit something. Sometimes it did. The rest of the time it's fighting bad payload data, cold grease, a dragging brake, or worn mechanics. The most-searched FANUC alarm for good reason.

Common causes

Ranked by what technicians most often find, most likely first.

Actual collision or external force - including tool stuck to the work ('tip stick').
Wrong payload settings (mass, center of gravity, inertia) - the most common false trigger.
Aggressive motion: ACC over 100, sharp CNT reversals, linear moves near singularity.
Cold plant, stiff grease - friction spikes after weekends and cold nights.
Brake dragging or low supply voltage.
Mechanical wear: reducer, balancer (listen for noise), or deeper hardware faults.

How to fix it

Inspect for a real collision first. To recover: hold SHIFT+RESET, release only RESET, keep SHIFT held and jog the axis AWAY from the obstruction.
Verify the payload schedule matches the actual tool and part; run payload ID if available.
If tied to one aggressive move, soften it (reduce ACC, smooth the reversal, reroute from singularity). The disturbance threshold is visible at STATUS > Axis > DISTURB - resist the urge to raise it to silence the alarm; that removes a protection layer.
After cold or idle periods, warm the robot at low speed before full-rate production.
One axis triggering repeatedly with clean payload data earns a mechanical inspection: brake release, reducer, balancer.

Quick facts

Category: Servo
Affected series: R-30iB; R-30iB Mate; R-30iB Plus; R-30iB Mate Plus
Alarm family: SRVO