GTCO CR 1212 - Users Guide - Manual (Page 4)

CR 1212 4
Section B: How the CR 1212 Works
CR 1212 translates the stylus/cursor position on the tablet into digital information and
communicates it to the host. The stylus/cursor position is expressed as an X, Y coordinate
pair. One coordinate pair is a report.
Valid reports can only be collected when the stylus/cursor is in the tablet’s active area and
in proximity:
 Active area is a 12-inch square area inside the groove on the tablet surface.
 Proximity is the maximum distance above the active area that the stylus/cursor can
be held and report a valid position. It’s approximately ½ inches, which means the
stylus/cursor and tablet do not need to be in direct contact with each other to issue
reports. There still can be up to a ½ inch of material (drawings, photos, etc.)
between the tablet and stylus/cursor, allowing it to issue reports.
The active area and proximity, in effect, establish a three-dimensional volume within which
the stylus/cursor can issue valid reports. Reports issued from outside of this volume are
out-of-prox and, therefore, do not represent the current position of the stylus/cursor.
Reports are measured in counts of resolution. Resolution is the fineness of detail that the
tablet can distinguish. It’s expressed in lines per inch (lpi) or lines per millimeter (lpmm).
This is slightly misleading, however. Resolution should be expressed in “bands per …” or
“lanes per …” because these lines have perceivable width at lower resolution settings.
The higher the resolution, e.g. 100 lpi or 200 lpi, the narrower the bands of resolution
become. Eventually, the bands become so narrow that they are easier to conceptualize as
lines of no measurable width.