Motion
Robot stops mid-cycle with a collision alarm but nothing was hit
SRVO-050 fires when the servo software estimates a disturbance torque too large for normal motion and concludes the robot hit something.
Most likely causes
Wrong payload settings (mass, center of gravity, inertia)
If the payload schedule doesn't match the real tool and part, the torque estimate is off and can cross the collision threshold during normal moves. A common false trigger.
Aggressive motion
ACC override above 100, sharp CNT reversals, and linear moves near a singularity where axes revolve at high speed can spike the estimated disturbance torque without any contact.
Cold plant, stiff grease
Low temperature raises friction, so the alarm can appear after weekends or cold nights when the robot runs before it's warmed up.
Brake dragging or low supply voltage
A brake that isn't releasing, or insufficient torque from low input voltage, both raise the load the software sees and can trip the collision estimate.
Mechanical wear
Reducer or balancer faults raise disturbance torque on the affected axis even without an external hit.
Actual collision or external force
It may be real. Tool stuck to the work ('tip stick') or any external force will trigger SRVO-050. Rule this out before chasing false triggers.
Where to start
- The group and axis appear in the brackets of the SRVO-050 message.
- Check whether the robot has collided or something increased mechanical load on the axis.
- Verify the payload schedule (mass, center of gravity, inertia) matches the actual tool and part.
- If it's tied to one aggressive move, look at ACC override, CNT reversals, and moves near singularity.
- After cold or idle periods, warm the robot at low speed before full-rate production.
- Check whether the brake of the affected axis releases, and confirm input voltage is within the rated range.
Still stuck? Start with the closest matching alarm reference.
Related alarm codes
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