bar code support

dlwild at gmail dlwild at gmail.com
Wed Dec 30 08:58:48 EST 2009


Hi Ruslan,

Check out the links:
http://en.wikipedia.org/wiki/PDF417

http://grandzebu.net/index.php?page=/informatique/codbar-en/pdf417.htm

In short, a pdf417 is a stacked linear bar code, and my particular use  
would be for inventory management. For those who don´t want to follow  
the link, here is an excerpt:

The PDF417 bar code (also called a symbol) consists of 3 to 90 rows,  
each of which is like a small linear bar code. Each row has:

a quiet zone. This is a mandated minimum amount of white space before  
the bar code begins.
a start pattern which identifies the format as PDF417. Every type of  
bar code symbology has a unique start and stop pattern.
a "row left" codeword containing information about the row (such as  
row number and what error correction rate the row is using)
1 - 30 data codewords : Codewords are a group of bars and spaces  
representing one or more numbers, letters, or other symbols.
All rows have the same number of codewords.
Every codeword contains four bars and four spaces (where the 4 in the  
name comes from).
The total width of a codeword is 17 times the width of the narrowest  
allowed vertical bar (the X dimension). This is where the 17 in the  
name comes from.
Each codeword starts with a bar and ends with a space.
There are 929 codewords to choose from, 900 for data, and 29 for  
special functions.
Each codeword is printed using one of three distinct clusters:
A cluster is a bar-space pattern for each of the 929 codewords
No bar-space pattern is repeated between clusters
The row number determines which cluster to use
The cluster is the same for all codewords in a row.
The purpose of clusters is to determine which row (mod 3) the codeword  
is in, allowing the scan to be skewed from the horizontal. For  
instance, the scan might start on row 6 at the start of the row, and  
be on row 10 at the end.
A "row right" codeword with more information about the row.
A stop pattern.
A quiet zone.
Along with the Data Matrix format, this symbolism can be used to  
generate postage accepted by the United States Postal Service. PDF417  
is also selected by the airline industry's Bar Coded Boarding Pass  
standard (BCBP) as the 2D bar code symbolism for paper boarding  
passes. PDF417 is the standard selected by the Department of Homeland  
Security as the machine readable zone technology for RealID compliant  
driver licenses and state issued identification cards.


The pdf 417 can encode up to 2700 bytes what explain its name of  
"Portable Document File". The encoding is done in two stages : first  
the datas are converted to "codeword" (High level encoding) then those  
are converted to bars and spaces patterns. (Low level encoding).  
Moreover an error correction system with several levels is included,  
it allows to reconstitute badly printed, erased, fuzzy or torn off  
datas.

The pdf417 symbols can store much more data than the regular bar  
codes, and it can contain redundant information in case the surface  
scrubs, get dirty, or otherwise damaged. It´s worth looking into if  
you want to produce a machine-readable/printable symbol that has more  
than the regular information found on bar codes and may be exposed to  
wear and tear due to storage or transport conditions.

All the best and thanks for the help,

Leonardo

On Dec 30, 2009, at 1:03 AM, Ruslan Zasukhin wrote:

> On 12/30/09 6:27 AM, "dlwild at gmail" <dlwild at gmail.com> wrote:
>
> Hi Leonardo,
>
>> Bar codes, great. I´m getting the 09 bundle so I´ll have Valentina,
>> although I haven´t worked with it yet. Any idea about the pdf417
>> reading-writing capacity?
>
> Valentina Reports can produce PDFs of course.
> Also PDFs with embedded XML.
>
> I don't know about PDF417. What is this?
> You always can add this as feature request.
>
> Reports do not have need to read PDFs AFAIK.
>
>> All the best,
>>
>> Leonardo
>> On Dec 29, 2009, at 10:11 PM, Lynn Fredricks wrote:
>>
>>>> Hello (Merry Christmas and a Happy New Year in advance),
>>>>
>>>> Anyone know if RunRev 4.0 supports or if there is a way to
>>>> create, print, read, regular bar codes or pdf417 bar codes
>>>> (http://en.wikipedia.org/wiki/PDF417
>>>> ) in revolution or related software?
>>>
>>> Valentina Reports can print bar codes, but necessarily its working
>>> with data
>>> stored in Valentina DB.
>>>
>>> Valentina Reports is, however, being given away for free with any
>>> new or
>>> upgrade orders placed through the Paradigma Website through the  
>>> end of
>>> December (so not long) - check it out at http://www.valentina- 
>>> db.com.
>
> -- 
> Best regards,
>
> Ruslan Zasukhin
> VP Engineering and New Technology
> Paradigma Software, Inc
>
> Valentina - Joining Worlds of Information
> http://www.paradigmasoft.com
>
> [I feel the need: the need for speed]
>
>
> _______________________________________________
> use-revolution mailing list
> use-revolution at lists.runrev.com
> Please visit this url to subscribe, unsubscribe and manage your  
> subscription preferences:
> http://lists.runrev.com/mailman/listinfo/use-revolution




More information about the Use-livecode mailing list