Lexmark MX722 Forms and Bar Code Card P4.2 Technical Reference - Page 137

PDF417 image widths and heights, MaxiCode capacity, Bar code horizontal alignment

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Lexmark Confidential until announced Appendix F - Deviations 137 PDF417 image widths and heights The BCE generates PDF417 images based on the algorithms found in the AIM PDF417 specification. The implementation of a PDF417 image can differ between manufacturers, depending on the interpretation of the specification. Because of this specification, some character length and ECC level combinations can produce images that differ from HP BarDIMM Pro or Forms and Bar Code Card. These images differ slightly in the number of rows and columns. A typical example is a PDF417 image with the following characteristics: • Character string "ABCDEFGHIJ" • An ECC level of 3 • Automatic rows and columns specified • Aspect ratio of 1.0 to 2.0 • PCL string: Esc(s3p2,1s24850TABCDEFGHIJ The results are the following: • HP BarDIMM Pro and Forms and Bar Code Card create an image with 2 columns and 11 rows. • The BCE creates an image with 1 column and 22 rows. • The data scanned by a symbol verifier from all three images is correct. This deviation is rare. When it does occur, it should not result in the loss of data that can be scanned. Note: Exact size compatibility of certain PDF417 bar code images with previous Lexmark bar code options is not guaranteed. However, the bar code still scans correctly. If the bar code image does not fit within the available space, then resize it to allow the placement of current and previous bar code images. You can also specify the number of rows and columns using the available PCL or PostScript controls. If the data stream controls are adjusted, then the corresponding image is the same on both current and previous bar code products. The image also fits within the available space. MaxiCode capacity The AIM MaxiCode specification defines the codewords that can be encoded. For more information, see "Mode: (Default = 02x)" on page 48. • A Mode 4 symbol holds 93 codewords. • A Mode 5 symbol holds 77 codewords. • The Mode 6 symbol capacity is not specified, but it should be the same as Mode 4 (no error correction). The original Forms and Bar Code Card encodes more than the maximum amount allowed by the AIM specification, but users must never exceed these values. Also, not all bar code readers can decode data more than the maximum allowed in the AIM MaxiCode specification. Bar code horizontal alignment Some UPC and EAN bar codes do not start at the existing PCL cursor position. These bar codes are shifted up to 3-4 mm on the left side and up to 2 mm on the right side. These instances are due to the presence of start characters, which may or may not shift the bar code (and HRT) to the right.

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PDF417 image widths and heights
The BCE generates PDF417 images based on the algorithms found in the AIM PDF417 specification. The
implementation of a PDF417 image can differ between manufacturers, depending on the interpretation of the
specification.
Because of this specification, some character length and ECC level combinations can produce images that
differ from HP BarDIMM Pro or Forms and Bar Code Card. These images differ slightly in the number of rows
and columns.
A typical example is a PDF417 image with the following characteristics:
•
Character string "ABCDEFGHIJ"
•
An ECC level of 3
•
Automatic rows and columns specified
•
Aspect ratio of 1.0 to 2.0
•
PCL string:
Esc
(s3p2,1s24850TABCDEFGHIJ
The results are the following:
•
HP BarDIMM Pro and Forms and Bar Code Card create an image with 2 columns and 11 rows.
•
The BCE creates an image with 1 column and 22 rows.
•
The data scanned by a symbol verifier from all three images is correct.
This deviation is rare. When it does occur, it should not result in the loss of data that can be scanned.
Note:
Exact size compatibility of certain PDF417 bar code images with previous Lexmark bar code options is
not guaranteed. However, the bar code still scans correctly. If the bar code image does not fit within the
available space, then resize it to allow the placement of current and previous bar code images. You can also
specify the number of rows and columns using the available PCL or PostScript controls. If the data stream
controls are adjusted, then the corresponding image is the same on both current and previous bar code
products. The image also fits within the available space.
MaxiCode capacity
The AIM MaxiCode specification defines the codewords that can be encoded. For more information, see
“Mode:
(Default = 02x)” on page
48
.
•
A Mode 4 symbol holds 93 codewords.
•
A Mode 5 symbol holds 77 codewords.
•
The Mode 6 symbol capacity is not specified, but it should be the same as Mode 4 (no error correction).
The original Forms and Bar Code Card encodes more than the maximum amount allowed by the AIM
specification, but users must never exceed these values. Also, not all bar code readers can decode data more
than the maximum allowed in the AIM MaxiCode specification.
Bar code horizontal alignment
Some UPC and EAN bar codes do not start at the existing PCL cursor position. These bar codes are shifted up
to 3–4 mm on the left side and up to 2 mm on the right side. These instances are due to the presence of start
characters, which may or may not shift the bar code (and HRT) to the right.
Lexmark Confidential until announced
Appendix F - Deviations
137