The Code 39 Extended barcode is a variable-length, alphanumeric, self-checking, bi-directional 1D barcode with an optional checksum for error detection. Code 39 Extended extends the Code 39 symbology to support the full ASCII character set.
Example Barcode
The following example barcode encodes the information "CODE 39 EXT" as an Code 39 Extended barcode:
Details
Extended characters are encoded by using a pair of Code 39 characters. For example, a lowercase "a" is encoded by the character pair +A. 1
Barcode Breakdown
Similar to Code 39 barcodes, each data character is made up of 5 bars and 4 spaces for a total of 9 elements. Each character includes 3 wide and 6 narrow elements. Thus, 3 out of the 9 elements are always wide, which is the reason why the symbology is sometimes called "Code 3 of 9".
Managing Organization
The Code 39 Extended is governed by ISO/IEC 16388. 1
Error Correction
Each Code 39 Extended barcode can include an optional modulo 43 checksum. Additionally, Code 39 symbology is self-checking.
Platform-Specific Notes
If you don't set the reader BarcodeTypes property to specifically look for Code 32 barcodes, the barcode engine might confuse a Code 32 barcode with a Code 39 Extended barcode (since Code 32 is a subset of Code 39 Extended and Barcode Xpress assumes the barcode is a Code 39 Extended when looking for Code 39 Extended or both).
By default, Barcode Xpress does not write optional checksums. If a checksum is required for Code 39, set the CheckSum property to 1(TRUE) and Barcode Xpress will calculate and write the checksum.
Code 39 requires a quiet zone, which should be at least the width of 10 narrow bars. This means that if you set the MinimumBarWidth property to 3 pixels (narrow bar size), you should set the HorizontalWhiteSpace property to 30 pixels.
If you don't set the reader BarcodeTypes property to specifically look for Code 32 barcodes, the barcode engine might confuse a Code 32 barcode with a Code 39 Extended barcode (since Code 32 is a subset of Code 39 Extended and Barcode Xpress assumes the barcode is a Code 39 Extended when looking for Code 39 Extended or both).
By default, Barcode Xpress does not write optional checksums. If a checksum is required for Code 39, set the CheckSum property to 1(TRUE) and Barcode Xpress will calculate and write the checksum.
Code 39 requires a quiet zone, which should be at least the width of 10 narrow bars. This means that if you set the MinimumBarWidth property to 3 pixels (narrow bar size), you should set the HorizontalWhiteSpace property to 30 pixels.
If you don't set the reader SetBarcodeReaderType method to specifically look for Code 32 barcodes, the barcode engine might confuse a Code 32 barcode with a Code 39 Extended barcode (since Code 32 is a subset of Code 39 Extended and Barcode Xpress assumes the barcode is a Code 39 Extended when looking for Code 39 Extended or both).
By default, Barcode Xpress does not write optional checksums. If a checksum is required for Code 39, set the WriteChecksumChar property to True and Barcode Xpress will calculate and write the checksum.
Code 39 requires a quiet zone, which should be at least the width of 10 narrow bars. This means that if you set the MakeBarcodeBarSize property to 3 pixels (narrow bar size), set the MakeBarcodeBWidth property to 30 pixels.
If you don't set the reader setBarcodeTypes method to specifically look for Code 32 barcodes, the barcode engine might confuse a Code 32 barcode with a Code 39 Extended barcode (since Code 32 is a subset of Code 39 Extended and Barcode Xpress assumes the barcode is a Code 39 Extended when looking for Code 39 Extended or both).
If you don't set the reader BarcodeTypes property to specifically look for Code 32 barcodes, the barcode engine might confuse a Code 32 barcode with a Code 39 Extended barcode (since Code 32 is a subset of Code 39 Extended and Barcode Xpress assumes the barcode is a Code 39 Extended when looking for Code 39 Extended or both).
By default, Barcode Xpress for Linux does not write optional checksums. If a checksum is required for Code 39, set the EnableCheckSum property to 1(TRUE) and the barcode engine will calculate and write the checksum.
Code 39 requires a quiet zone, which should be at least the width of 10 narrow bars. This means that if you set the MinimumBarWidth property to 3 pixels (narrow bar size), you should set the HorizontalWhiteSpace property to 30 pixels.
If you don't set the reader type parameter to specifically look for Code 32 barcodes, the barcode engine might confuse a Code 32 barcode with a Code 39 Extended barcode (since Code 32 is a subset of Code 39 Extended and Barcode Xpress assumes the barcode is a Code 39 Extended when looking for Code 39 Extended or both).
By default, Barcode Xpress detects Code 39 Extended barcodes only with start and stop patterns. Use the Code39StartStopPatternsAreMandatory property to seacrh for Code 39 Extended barcodes without start and stop patterns.
Similar Barcode Types
Barcode Variants
Code 39 Extended is a variant of Code 39, extending it to support the full ASCII character set.
Related Barcodes
Code 93 barcodes were designed to increase data density and integrity in comparison to Code 39 symbology.
References
- "Code 39 Bar Code Symbology Specification." ISO/IEC 16388:2007, ISO/IEC, Feb. 2008, www.iso.org/standard/43897.html.
For additional background and use-case information see our Code 39 Extended barcode page.
For more information, see the Barcode Xpress SDK product page or try our online demos.