This can be internal or external. Position Error Position error is the difference between the theoretically correct shaft position and its position as indicated by the encoder cycle count. Quadrature Quadrature is the term for two identical periodic signals when the phase displacement is nominally 90 electrical degrees. Quadrature Error Quadrature error is the phase error when the specified phase relationship between any two channels is nominally 90 electrical degrees. Radial Load Radial load is the force applied to the encoder shaft perpendicular to the axis of rotation.
Resolution is theoretically unrelated to accuracy.
Rotary pulse generator is another term for incremental encoder. Symmetry Symmetry is the ratio of the ON time to the OFF time of the output signal for one channel. It is typically expressed in oz-in.