Creating the formula
While every requirement will need a different formula there are some general points that should be taken into account when creating the formula to generate the barcode symbols. Every formula will need to specify a CodeType and we recommend the use of the Xunit parameter to specify the basic element width for the symbol, so every symbol will start with code of the form:
"http://localhost/dlbc2d/dlbc2d.aspx?CodeType=1&Xunit=16
Many barcode types have a variety of Modes – for example Databar symbols can be generated in any one of seven modes – so you may need to check whether the barcode type you wish to use has any mode requirements, If it does then code such as
&Mode=1
may need to be included.
PDF417, MicroPDF417 and all Databar symbols are made of bars which are not square but have a height which is a multiple of the width of the narrowest bar (the Xunit value). The multiple is specified using the Ysize parameter. For PDF417 symbols this can range from 2 – 5, while for Databar symbols it can be in the range 7 – 50. So to generate one of these symbols the formula must contain code of the form
&Ysize=20
Many other optional parameters are available and are listed in the Reference section.
Finally every formula needs to end with code that specifies the Data, using code of the form &Data=12345 or, much more likely, &Data= followed by the source of the data, for example
http://localhost/dlbc2d/dlbc2d.aspx?CodeType=7&Xunit=12&Mode=6&Columns=3&Ysize=30&Data=+{fieldname}
for a Databar Expanded-Stacked symbol with an Xunit value of 12 Mils, a bar height of 30* Xunit, 3 codeword pairs in the first row, and the data taken from a field name fieldname.
Concatenating data
fields