TransAct Epic 3000, Руководство программиста

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Epic 3000 Programmer’s Guide Programming Codes
100-14362 Rev A Page 117
Data Matrix Bar Code
This is a 2-D matrix symboligy barcode that can encode numeric or alphanumeric data
and includes error correction. There are 4 original error correction ECC-000
– ECC-140
as well as the standard Reed-Solomon ECC-200 error correction. Most current
scanners only support ECC-200. In theory 3116 numeric and 2335 characters can be
encoded in Data Matrix. From a practical point of view the limited print width of the EPIC
3000 limits the maximum size of the barcode.
The Data Matrix barcode matrix may be square or rectangular and only specific sizes
are allowed. You may select a size and you may limit the selection to square only,
however, if you limit the size, you must leave enough room for the data or the printer will
automatically select a larger matrix. The commands to control 2 dimensional barcode
options start on page 150.
Data Matrix Encoding
As referred to above, there are 2 basic encoding schemes defined for Data Matrix
barcodes; ECC 000
– 140 and ECC 200. ECC 200 which uses Reed-Solomon error
correction and is recommended for all new applications. ECC 000 - 140 is the older
system and only supported by a few older scanners. As ECC200 is the recommended
encoding, it is the only version supported by the EPIC 3000.
Data Matrix ECC200
ECC200 is actually 6 encoding schemes. The data to be encoded is scanned and the
optimal encoding scheme or combination of schemes is used to encode the symbol.
The resulting encoded data is then processed with the Reed-Solomon error correction
algorithm and the resulting information is formatted into a Data Matrix barcode.
Note : The ISO/IEC 16022:2006 specification defines how the ECC200
encoding schemes are to be evoked, however in some cases the resulting
size of the compressed data is identical with 2 or more different encoding
sequences. The ISO standard is followed by the EPIC 3000 however it is
possible that other generators will generate different barcode patterns that
are equivalent.
Encodation scheme Characters Bits per data character
ASCII double digit numerics 4
ASCII values 0 - 127 8
Extended ASCII values 128 -
255 16
C40 Upper-case alphanumeric 5,33
Lower case and special
characters 10,66
*
Text Lower-case alphanumeric 5,33
Upper case and special
characters 10,66
**
X12 ANSI X12 EDI data set 5,33
EDIFACT ASCII values 32 - 94 6
Base 256 All byte values 0 - 255 8
* encoded as two C40 values as result of use of a shift character
** encoded as two Text values as result of use of a shift character
Table 6 Encoding schemes for ECC 200