PDF417 2D Barcode

PDF417 is a barcode symbology with the following basic characteristics:

• Encodable Character Set:
  • Text compaction mode permits all printable ASCII characters to be encoded, i.e. values 32-126 inclusive in accordance with ISO/IEC 646 (IRV), as well as selected control characters.
  • Byte compaction mode permits all 256 possible 8-bit byte values to be encoded. This includes all ASCII characters value 0 to 127 inclusive and provides for international character set support.
  • Numeric Compaction mode permits efficient encoding of numeric data strings.
  • Various function codewords for control purposes.

• Symbol character structure:

  Each PDF417 symbol consist of a stack of vertically aligned rows with a minimum of 3 rows (maximum 90 rows). Each row shall include a minimum of a 1 symbol character (maximum 30 symbol characters), excluding start, stop and row indicator columns. The symbol shall include a quiet zone on all four sides. Each character is 17 modules wide: 4 bar and 4 space elements with the largest element 6 module wide. SE450 specifies each module is 2 dots line wide.

• Maximum possible number of data characters per symbol (at error correction level 0): 925 data codewords which can encode:
• Text Compaction mode: 1850 characters (at 2 data characters per codeword).
• Byte Compaction mode: 1108 characters (at 1.2 data characters per codeword).
• Numeric Compaction mode: 2528 characters (at 2.93 data characters per codeword).

At the minimum recommended error correction level, there is a maximum of 863 data codewords which can encode:

• Text Compaction mode: 1726 characters (at 2 data characters per codeword).
• Byte Compaction mode: 1033 characters (at 1.2 data characters per codeword).
• Numeric Compaction mode: 2528 characters (at 2.93 data characters per codeword).
• Symbol size:
• Number of rows: 3 to 90.
• Number of Columns: 1 to 30
• Maximum codewords capacity: 928 codewords.
• Maximum data codewords capacity: 925 codewords.
• Selectable error correction: 2 to 512 codewords per symbol.

But due to the limitation of SE450’s 2” Print head, the maximum data user can send in portrait and landscape mode as following:

Portrait mode: Any giving Dymo label can hold the maximum PDF417 barcode symbol column and row specified as following:

Column: 10

Row: 90

That gives user: the maximum characters with error correction level 0 sent to SE450 are:

• Numeric Compaction mode: 1318
• Byte Compaction mode: 540
• Text Compaction mode: 900
• At error correction level 4:
• Numeric Compaction mode: 1224
• Byte Compaction mode: 836 Text Compaction mode: 501
• If the pdf417 barcode is too large to print in portrait mode, it will be printed in landscape mode, after printing the barcode, it will resume to portrait mode again.

Landscape mode

Maximum column is 30 and maximum raw is 74. In landscape mode, user can send the maximum data according to PDF417 specification which is described previously.

With current firmware setup, SE450 switches to landscape mode if user sends the data is too large for portrait mode to hold a complete PDF417 symbol image.

GS k command has different parameters in PDF417 2D barcode, it is defined as following:

ASCII GS k n c r e m1 m2 dl….dm

Decimal 29 107 n c r e m1 m2 dl….dm

Hex 1D 6B n c r e m1 m2 dl….dm

Parameters:

n = 14: specify it is PDF417 2D barcode.

c = user defined symbol column number (1 to 30 in landscape, 1 to 10 in portrait), if it is 0, which means the column will be calculated according to PDF417 specification by SE450 Firmware.

r = user defined symbol row number (3 to 74 in landscape, 3 to 90 in portrait); if it is 0 which means the raw will be calculated according to PDF417 specification by SE450 Firmware.

e = user defined error correction level (0 to 8), if it is 0 which means the error correction level will be set according to PDF417 specification. It will be assigned as per the following Table:

m1 = the most significant byte of data length.

m2= the least significant byte of data length.

Total data length = m1 * 256 + m2

Example

GS ‘k’ 0x0E 0x0 0x0 0x0 0x0 0x23 “This is a PDF417 Test, test 1234567”

prints the following PDF417 image: