Opticon LH2 - Manual (Page 22)

Chapter 3
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Chapter 3
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4) Imager Field of View & Resolution
The LH2’s dual field optical system may be modified based on your scanning environment.
The LH2’s mega pixel imager may be set to the following two modes:
SXGA Mode: In standard SXGA mode (default), the 1.3 Million Pixel imager is divided
into near field and far field decode zones. In each zone the resolution is 1024 x 640 pixels
(see figure 3.2). In this mode of operation, the highest resolution, and therefore, widest
working range on symbols of all densities is achieved. The trade-off is the amount of
time the reader spends processing the image. This time can be reduced by optimization
functions.
If only the near field is used (small, high density symbols), the far field image can be
ignored. If only the far field is used (large, lower density symbols), the near field can be
ignored. Further optimization may be obtained by “windowing” the field to a smaller area.
Each focal area may be narrowed by enabling the windowing feature found in Appendix
A.
VGA Mode: In VGA mode (optional selection), the 1.3 Million Pixels are sampled on a 4-
to-1 basis. This greatly reduces the amount of time necessary for the transfer of the image
to the CPU and the resulting processing time (figure 3.3). The trade-off for this increased
speed is a reduction in resolution and working range.
NOTE: In the following section the LH2 can ONLY be programmed
by scanning the bar codes. For detail serial commands read the
Appendix A - Optimization Matrix section.