dLSoft  barcode & labelling software     

Barcode information - 2D types

Common 2D barcode types (follow links for linear 1D types or clocked types)

 

Codablock F

Codablock is a stacked barcode symbology based on Code 128. It can encode the full ASCII character set in a symbol which consists of multiple rows of Code 128 type symbols, using a common “Start A” start character and a common “Stop” stop character. Apart from the start and stop character the other characters in adjacent rows have a horizontal line between them.

Codablock F stacked barcode

Each row in a Codablock symbol contains (in addition to the common start and stop characters) a subset selector, a row indicator and a check digit, along with a number of data characters. This enables each row to be read by Code 128 scanners.

Codablock symbols can hold a maximum of 2725 characters, although this value is significantly reduced by the presence of subset change characters. Codablock symbols can have between 2 and 44 rows, and each row can hold between 4 and 16 characters plus the subset selector, row indicator and check digit.

Codablock symbols are character self-checking and may be scanned in any direction. The subtypes used in the symbol are essentially identical with those use in Code 128 symbology.

 


Code 16k barcodes

Code 16k barcodes are stacked barcodes which encode characters using a reverse video version of Code 128. Each row starts and ends with a UPC digit, which indicates the row number and the direction of scan.

 Code 16k barcode

Each row encodes 5 data characters and the Code 128 type C mode is used for numeric-only strings. A maximum of 16 rows are permitted.

Code 16k has three coding schemes and permit the inclusion of special characters not present on the keyboard. If no coding scheme is specified scheme B is used by default. Scheme C is used for any code, which has numbers in the first four digits. An alternative scheme may be selected within dLSoft products by selecting one of the following Start modes:

Start mode

Code set

leading char

0

A

 

1

B

 

2

C

 

3

B

Fnc1

4

C

Fnc1

5

C

Shift B

6

C

Double Shift B

 


Code 49 barcodes

A code 49 barcode is a stacked symbol containing between 2 and 8 rows, each separated by a separator bar. Each row contains 16 “words” (which are generated from character pairs) and a start and stop character. The last row also contains the number of rows in the symbol and the check digit characters.

Code 49 stacked barcode

There are 2400 possible words which can be generated from each pair of characters (by taking the value of the right hand character plus 49 time the value of the left hand character). Symbols with less than 7 rows contain 2 check digits in the final row. Symbols with 7 or 8 rows contain 3 check digits in the final row.

A numeric mode allows 5 digits to be encoded in the same space as three alphanumeric characters, so offering a higher density.

Encoding Code 49 symbols may be accomplished only in Auto mode and there is no user choice in the number of rows or columns in a Code 49 symbol.

 


Maxicode symbols

MaxiCode is not really a barcode – it doesn't have any bars. It is a fixed size matrix symbology made up of offset rows of hexagonal modules, with a Finder pattern in the centre.

MaxiCode symbols are reproduced at a width of 25.5 mm and a height of  24.4 mm (in each case there is a tolerance of 1.5 mm).

Intended primarily for encoding addresses for postal and delivery applications, it has a relatively low information content. On the other hand the fixed physical size of the image simplifies the facilities required for both printing and scanning the symbols.

Maxicode symbol

MaxiCode is characterised by the two "messages" which make up its data content – the Primary message and Secondary message. The symbology may be used in 5 modes which utilise the two message in different ways and with different levels of error correction, as shown in the table below:

 

Mode

Use

0

obsolete (not supported)

1

obsolete (not supported)

2

Primary message encode numeric postal code, country code and service code,    secondary message encodes additional data

3

Primary message encode alphanumeric postal code, country code and service code, secondary message encodes additional data

4

Any data up to 84 data characters automatically split between primary and secondary messages.

5

Any data up to 68 data characters automatically split between primary and secondary messages. Enhanced error correction used

6

Similar to 4, but used for reader control.

 

In modes 4, 5, and 6 virtually any ASCII data may be encoded up to the maximum number of data characters allowed. However, encoding introduces additional shift and latch characters whenever characters other than uppercase letters and numbers are used and the maximum length of text becomes correspondingly smaller.

Modes 2 and 3 are for Structured Carrier Messages and require specific data in the correct order to produce a scan able symbol. Basically the data consists of the sequence:
postal code G country code G service class G secondary message
where the 4 components are separated by ASCII 29 characters, shown as G.

In mode 2 the postal code must be numeric only and up to 9 digits. In mode 3 the postal code may be up to 6 alphanumeric characters. The country code and service class elements must be three digits each.

Mode 2 or 3 message which begin with the sever character sequence [)>R01G (where G is ASCII 29 and R is ASCII 30) are treated in the special way described in the MaxiCode specification. Any secondary message can terminated with an End of Transmission character (ASCII 4).

Because the non-printable ASCII characters are a required part of MaxiCode messages in Modes 2 and 3, dLSoft software recognises the following keyboard sequences for the entry of such characters:

Sequence

ASCII value

<FS>

28

<GS>

29

<RS>

30

<ET>

4

An example of a Caption string for a Mode 2 Maxicode is:

[)><RS>01<GS>96152382802<GS>840<GS>001<GS>1Z00004951<GS>UPSN<GS>06X610<GS>159<GS>1234567<GS>1/1<GS><GS>Y<GS>634 ALPHA DR<GS>PITTSBURGH<GS>PA<RS><ET>

Appended symbols are not supported by dLSoft software at this time.

MaxiCode symbols are sensitive to the gap between hexagons. For printing on a 300 dpi laser we recommend the line width reduction parameter be set to 12.