Position Following Error

When error [4.1025] occurs, the following symptoms may appear:

• An axis stops abruptly while moving, the error is raised and the servo turns off.
• In palletizing or high-speed transfer sections, the error repeats at corner blending or sudden stops.
• From Param 1, you can identify which inverter (joint) the error occurred on.

[4.1025] Robot inverter category

Position Following Error
Param 1: Inverter Number
Param 2: 0x8611

This error means the gap between the commanded position and the actual position of a joint exceeded the allowed range — the joint could not follow the command.

• Excessive payload, or an aggressive motion profile — a payload setting different from the actual load, or acceleration and corner blending set too high for the load.
• External force or collision — contact with a product, jig or surrounding equipment pushes the axis out of position.
• Power supply, grounding or noise — in this case communication or power related errors usually appear as well.
• A fault in a joint — the encoder, the reducer, the brake or the position setting of one joint. This needs service.

• Verify that the total load, including the tool, workpiece and jig, does not exceed the robot specification, and that the payload setting (mass and center of gravity) matches it.
• Check the joint and task speed, acceleration and deceleration, and corner blend radius in the section where the error occurs. Reduce them if they are excessive.
• Pay particular attention to a sudden stop or direction change within a short distance under heavy load, and to high-speed rotation near a joint limit.
• Check whether a collision occurred recently, and for interference with cable trays, jigs or surrounding equipment.
• Note whether the error always occurs on the same axis, in the same posture or section.

If the load and the program are within the normal range and the error continues, contact your distributor. See also Position Following Error with Large Blend Values – Why Does It Occur?

• Robot model and serial number
• Software version of the controller
• The error code with its Param values, all codes shown with it, and the date and time
• The payload setting, and the speed, acceleration and blend settings of the motion
• The controller log exported right after the error

• 4.1049 Incremental Encoder Count Error
• 4.1003 Malfunction by the electric motor over-current
• 4.1031 Inverter Over Current Error (H/W)
• 2.9011 Collision has been detected