Generate Data Matrix Barcodes

Overview

Data Matrix is a 2D matrix symbology used to generate barcodes of rectangular and square shapes. It is a widespread industrial standard that can be used to encode characters and streams of bytes. Maximum configuration of Data Matrix contains up to 144 rows and columns and allows encoding at most 3,116 numerical digits or 2,335 ASCII symbols or 1,555 bytes. The Data Matrix barcode data includes special information for integrity verification and error correction. The error correction mechanism allows reading barcodes with severe damages. Data Matrix includes two standards described in the table below.

Data Matrix Standard Description
ECC 000-140 Several obsolete standards that enable square barcode configuration only, use outdated encoding algorithms and support convolutional error correction. It is recommended not to apply these standards to business-as-usual goals as they currently serve only to execute industrial tasks that are compatible with outdated instructions
ECC 200 Modern standard that enables both square and rectangular barcode configurations, utilizes modern encoding methods and supports Reed-Solomon error correction. It is applicable to any up-to-date application

Data Matrix ECC Standards

To enable the required Data Matrix standard, developers can use the setDataMatrixEcc function of class DataMatrixParameters. This function allows setting one of the supported standards: ECC 000-140 (outdated standards) or ECC 200 (recent universal standard) using the values available in the DataMatrixEccType class. The value of DataMatrixEccType.ECC_200 is set by default.

ECC 200

The ECC 200 standard can be set using the setDataMatrixEcc function and passing values ECC_AUTO or ECC_200. ECC 200 is compatible with all encoding modes specified in the DataMatrixEncodeMode class. Moreover, it allows encoding Unicode characters using the setCodeTextEncoding function. The capacity of additional recovery information required for error correction is precisely limited for barcodes according to their size.

ECC 000-140

ECC 000-140 standards can be applied only to a few encoding modes included in the DataMatrixEncodeMode class, i.e. AUTO, FULL, and ASCII. All other encoding modes are processed as FULL by default. The setCodeTextEncoding function is not applicable to these standards and therefore, encoding Unicode characters is not supported. Barcode layout confirgurations of ECC 000-140 differ significantly from ECC 200. At the same time, different standards corresponding to ECC 000-140 are quite similar between each other and only have different data recovery capacity, as explained below.

ECC Standard Data Recovery Capacity
ECC_000 Only error detection
ECC_050 2.8%
ECC_080 5.5%
ECC_100 12.6%
ECC_140 25%

Encoding Modes

Aspose.BarCode for PHP via Java supports various encoding modes that are defined in the DataMatrixEncodeMode class that provides nine encoding modes, as described below. The AUTO encoding mode is used by default.

Encoding Mode Description
AUTO Similar to ASCII
ASCII Encodes both ASCII characters and streams of bytes; characters from 128 to 255 are encoded with two bytes. The FULL mode is recommended to encode streams of bytes
FULL Encodes any symbol in 8 bits. This mode is recommended to encode byte streams
CUSTOM Uses the encoding determined in CodeTextEncoding; thereafter, the generated stream of bytes is further processed through the FULL mode
C40, TEXT, EDIFACT, and ANSIX12 Encode predefined sets of symbols using special industrial encodings, i.e. C40, Text, EDIFACT, and ANSI X12
EXTENDED_CODETEXT Gives flexible control over encodings and allows setting the required encoding for a part of the input message manually

For all encoding modes except CUSTOM, the encoding determined in CodeTextEncoding is used to process input information that includes a Unicode symbol (any character with the value over 255). The CUSTOM mode is enabled in the ECC 200 standard only. Further in the article, it is explained how to manage different encoding modes.

AUTO and ASCII Encoding Modes

AUTO and ASCII encoding modes allow encoding ASCII symbols and byte streams. However, encoding characters from 128 to 255 takes two bytes for each character. In cases when input text includes Unicode symbols, information needs to be re-encoded with the use of the encoding determined in CodeTextEncoding.

Encoding Streams of Bytes in FULL Mode

The FULL mode is used to encode streams of bytes. In this mode, each byte is encoded with 8 bits. If input barcode data contains Unicode characters, information gets re-encoded with the encoding set in CodeTextEncoding. It is possible to represent text lines by calling the setTwoDDisplayText function.

Encoding Unicode Text in CUSTOM Mode

In all cases, the CUSTOM encoding mode implies first re-encoding barcode information into a stream of bytes. Thereafter, the generated stream gets processed in the FULL mode; here, each byte is encoded using 8 bits.

Extended Encoding Controls in EXTENDED_CODETEXT Mode

The EXTENDED_CODETEXT mode allows encoding input data applying various encodings to different parts of barcode text if requested by specific industrial standards. It is possible to combine different supported encodings, i.e. AUTO, ASCII, C40, TEXT, ANSIX12, and EDIFACT.

It is necessary to formulate a barcode text message using the following form: "\Encoding_mode_name:text\Encoding_mode_name:text". It is necessary to double all backslashes in text. To display the text message under a barcode, it is required to call the setTwoDDisplayText function.

$generator = new BarcodeGenerator(EncodeTypes::DATA_MATRIX);
$generator->setCodeText("\\ansix12:ANSIX12TEXT\\ascii:backslash must be \\\\ doubled\\edifact:EdifactEncodedText");
$generator->getParameters()->getBarcode()->getDataMatrix()->setDataMatrixEncodeMode(DataMatrixEncodeMode.EXTENDED_CODETEXT);
$generator->getParameters()->getBarcode()->getCodeTextParameters()->setTwoDDisplayText("My Text");
$generator->save("test.png", BarcodeImageFormat::PNG);

Special Industrial Encoding Modes: C40, TEXT, EDIFACT, and ANSIX12

Various special encoding modes, such as TEXT, C40, EDIFACT, and ANSIX12, can be used to encode barcode information in forms compatible with specific industrial requirements. These modes are applicable to industrial tasks only.

Layout Settings

The layout for Data Matrix barcode generation can be determined through setRows and setColumns functions of class DataMatrixParameters. If they have not been used explicitly, the barcode library identifies a layout that is optimal for the size of input data. Barcode layout configurations are different in ECC 000-140 and ECC 200 standards. Only ECC 200 allows modifying the number of rows and columns. In ECC 000-140 standards, the suitable barcode layout configuration is determined automatically. The ECC 200 standard prescribes setting even numbers of rows and columns. In other words, it supports the following layout configurations: 8 x 18; 16 x 48; 10 x 10; 144 x 144.

Layout Settings 22 Rows and 22 Columns 12 Rows and 36 Columns

Working with Macro Characters

Aspose.BarCode for PHP via Java supports the use of macro characters in Data Matrix barcodes. The Data Matrix standard allows encoding industry-specific headers and trailers in a single character. This feature leads to the reduction of the number of symbols for data encoding owing to the use of dedicated structured formats. Macro characters can be useful to implement particular industrial needs. It is necessary to set a macro character in the first digit position.

Aspect Ratio Settings

Aspect Ratio is one of the most important parameters defined as the ratio between barcode height and width. The barcode library provides the setAspectRatio function of class DataMatrixParameters that allows managing barcode proportions based on the X and Y coordinates. Aspect Ratio is determined as a relative coefficient to XDimension. Usually, it is recommended to set the value of Aspect Ratio equal to 1.

Aspect Ratio Is Set to 1 Is Set to 0.5
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