Barcode Application
peter.villanueva
I like to write a barcode application with delphi 7. I had never done it
before. I wonder:
1. What kind of equipment do I need? A barcode reader?
2. How many different kinds of Barcode out there? I need to write an
inventory tracking system for a wholesale company, what kinds of barcode
should I handle in general?
3. Any sample application out there?
4. What database column type should I use for storing the barcode?
5. Do all commodities have a barcode?
Thanks in advance.
Peter
Ian Hinson
and often just plug into a keyboard port. A Y-connector is used so you can
still have the keyboard connected at the same time.
When you scan a code with the device its just the same a *typing fast*.
No special software is needed in the reading part. It's all done by the
barcode reader that outputs the equivalent keystrokes into to keyboard
input.
Scanners even simulate pressing the <Enter> key when they've reached the
end, so that application software will know there's no more to come for that
field.
> 2. How many different kinds of Barcode out there? I need to write an
> inventory tracking system for a wholesale company, what kinds of barcode
> should I handle in general?
A common code used for homegrown inventory codes is Code 3 of 9 (aka Code39)
since its the simplest and easy to print barcodes of this type.
But there are other coding schemes. They all work on a similar principle
(bands and bar widths).
Read about it at http://www.barcode-1.com
You'll have to find out what coding is used on the barcodes you will be
reading.
In any case - whichever barcode standard is used is NOT the problem for the
software. It's more relevant to purchasing a barcode reading wand that
understands that particular scheme. But what comes out of the wand is just
the same - letters and numbers.
> 3. Any sample application out there?
You don't need any sample application. There's *nothing special* about the
application itself.
Its all done with the reader wand that acts like a fast keyboard.
(Ever seen check-out cashiers just "type in" a number by hand when a code
won't scan properly?)
> 4. What database column type should I use for storing the barcode?
Depends on what appears on the barcodes you will be reading.
Barcodes support alpha-numeric, so a text field of sufficient length may be
needed.
On the other hand, if you know will be reading barcodes that only contain
numerics, then an integer field can produce indexing efficiencies for the
database in the long term.
> 5. Do all commodities have a barcode?
You're the one writing the app - surely you'll be targeting it at a specific
market?
Barcodes are a side-issue.
> Thanks in advance.
> Peter
Jeff Labute
I have a few barcode applications... and a barcode reader with a serial
interface would be best.... then you can use a barcode at any point in your
code... not expecting keyboard input. Metrologic has some good cheap
barcode readers. Lots of serial communications toolkits available
like...Async Pro which is a commercial package..now available for free on
sorceforge. It would be faster if your application could accept a barcode
at any point without having to be at a particular place on a screen or
anything.
Code 39? there are lots. Also, there are barcode components available for
printing them etc. Check out systools from turbopower on sorceforge too.
Jeff
"peter.villanueva" <peter.vi...@attbi.com> wrote in message
news:9Pn1a.42490$tq4.2742@sccrnsc01...
Jeff Labute
by keyboard) and many attributes of the barcode scanner are
configurable..like..inter-character delays, or non-repeating scans... and
pauses between scans..etc. Code39 is common enough. If you store it in a
db column...it can be VARCHAR, or an integer... depends on how you index
your products. You can massage the data once you receive it from the
scanner. Personally, i like serial... since a keyboard buffer is small...
and you can have a large serial buffer... it is fast... and you can have a
few of them connected to 1 PC is you wanted. etc.
The barcode reader should have a "decoder" built in to it... otherwise...
you will not get anything useful out of it. Most do... just beware. In my
application... the barcode has a few alpha characters, then a few
numbers...like
XX123456. The scan triggers on the XX since it is always the same on the
membership cards... reads in the 123456 and interprets it as an integer for
a membership... with the company ID being XX for example. You can do
anything you like really... the sky is the limit.
Jeff Labute
"peter.villanueva" <peter.vi...@attbi.com> wrote in message
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