Centering

Use Centering to narrow the image scanner’s field of view to make sure the image scanner reads only those bar codes intended by the user. For instance, if multiple codes are placed closely together, centering will insure that only the desired codes are read. (Centering can be used in conjunction with Aimer Delay, page 4-12,for the most error-free operation in applications where multiple codes are spaced closely together. Using the Aimer Delay and Centering features, the image scanner can emulate the operation of older systems, such as linear laser bar code image scanners.)

In the example below, the gray area is the full image scanner field of view and the white area is the centering window. Bar Code 1 will not be read, while Bar Code 2 will be.

Bar Code 1

Bar Code 2

The default centering window is a 128x96 pixel area in the center of the image scanner’s field of view. The following diagram illustrates the default top, bottom, left, and right pixel positions, measured from the top and the left side of the image scanner’s field of view, which is 640 by 480 pixels.

40%

60%

100%

0

To

40%

Botto Default

Center

60%

Left

Right

100%

If a bar code is not within the predefined window, it will not be decoded or output by the image scanner. If centering is turned on by scanning Centering On, the image scanner only reads codes that intersect the centering window you specify using the Top, Bottom, Left, or Right bar codes.

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