Overview

Compensation functions of WMX3 can be used to compensate for imperfections in the physical machine which may cause the physical position of an axis to differ from the command and feedback positions of the axis.

Compensation functions will add an offset to the command position of the axis before sending the command to the servo, and subtract the same offset from the feedback position of the axis on the next cycle. This is illustrated in the following figure.

The compensation offset that is applied depends on the command position of the reference axis (for Pitch Error Compensation and Two-Dimensional Pitch Error Compensation) or the recent direction of motion of the axis (for Backlash Compensation).

The compensation offset does not affect the command position and feedback position values handled by the user. The command position of the axis does not change with the compensation offset. The feedback position of the axis also does not change with the compensation offset, assuming the servo motor accurately follows the command position.

The compensated command position of the axis equals the command position plus the compensation offset. This status changes with the compensation offset. The compensated feedback position of the axis equals the feedback position plus the compensation offset (thus, the feedback position equals the compensated feedback position minus the compensation offset). This status also changes with the compensation offset.

The encoder command and encoder feedback statuses contain the command to the servo and the feedback from the servo. These statuses change with the compensation offset.

The total compensation offset and the compensation offset of each type of compensation can be found in the compensation structure obtained by the GetStatus function.

Compensation offsets are only applied to axes operating in Position mode.