A contactless, electromagnetic replacement for cabled Standards-based interfaces which handles data transfer requirements associated with the Standard, and capable of measuring and replicating relevant physical conditions on data lines so as to function compatibly and transparently with the Standard. The first bias voltage line is electrically connected at opposite ends thereof to the second bias voltage line. The grooves may have two groove walls that continues via a rounded region into a shared groove base. Surface curvature data is prepared on the reflective surface in relation to positions of the first and second masks.