A method and apparatus are provided for tracking customer purchases using a unique anonymous identifier. Declared effect is achieved due to that circuit containing storage unit, indication unit, paraphase data input, paraphase data output, and indication output, is modified by adding two inverters and preindication unit. The hub has a lumen that has a groove. Rotational positions of the rotatable member are detected by the detector. The light emitted from the semiconductor laser is S-polarized light that oscillates in a direction perpendicular to the plane of incidence. A third phase of the communications protocol can also be asynchronously transmitted with the first and second phases.