A following-error trip means the monitored position relationship exceeded its configured condition. It does not identify whether the cause is mechanical, electrical, feedback-related, or tuning-related. Capture command, actual position, velocity, and torque or current together before changing the tolerance.

Diagnostic framework; fault definitions and acceptable limits depend on the motion system.

What is happening?

Position error reflects a difference between the commanded trajectory and reported motion under the controller's definition. Load demand, acceleration, binding, limits, and feedback problems can all affect it. A larger error threshold may hide the symptom without improving motion or protecting the process.

Check these five things

1. Record the exact fault and the point in the motion profile where it occurs.

2. Compare command and actual position with available velocity and torque/current traces.

3. Review mechanical load, friction, brakes, and recent changes using approved isolation procedures.

4. Check feedback health, scaling, and commissioned motion limits against the documentation.

5. Have the responsible motion engineer assess profile or tuning changes through a controlled test plan.

Worked example

A simulated axis follows a low-load move but falls behind during a loaded acceleration. Torque reaches its configured limit while position error grows. That evidence supports a load/profile investigation, but it does not rule out mechanical resistance or incorrect configuration.

Quick diagnostic reference

The mistake to avoid

Increasing the following-error limit is not a diagnosis. Determine whether the axis can meet the required trajectory within its capabilities.

How to verify the fix

Document acceptable tracking error and motion quality under representative load without exceeding equipment or process limits.

Field-work boundary: These are educational diagnostic guides. Use the exact equipment manuals and approved site procedures. Electrical testing and machinery changes belong to qualified, authorized personnel; control hazardous energy and validate affected functions before release.

Technical reference

Rockwell Automation: axis status and position-error-related attributes. The examples and diagnostic tables above are original teaching material; they do not replace the product manual.

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