[Gloucs] barcoding

[Dave Elliott]

Guy,

  I have never had the good or bad fortune to actually have to set a system
up (excepting some involvement in printing address barcode labels from JDE
ERP system) but as your question was so delightfully broad, perhaps a few
pointers of my 'understanding' of the situation might provoke a useful
thought or two. Please take all notes in the good spirit they are provided
... and obviously without warranty..

Bar Codes
You probably already know it but there are quite a few different coding
systems - you need to ensure your printers and scanners are compatible with
the chosen one.

Scanners:
1/ These come in a wide variety of guises - with as many interfaces as you
can think of. However many can be obtained with a 'simple interface e.g.
Symbol technologies (www.symbol.com) advertise LS1900 range with options
including PS/2 keyboard wedge (i.e. it slipstreams into the keyboard cable
with the aim of fooling the PC the code had just been typed), RS232 and USB
options. I would assume that your main problems will be persuading the
'userware' software - such as warehouse database to make sense of the codes
being fed to it rather than the operating system - be it Linux or ANother -
which will simply relay the incoming data stream. Are you intending to write
your own 'userware' addition? I am assuming the chosen OS provides low-level
support for serial and USB - and obviously the keyboard one is trivial.

A small beware - check carefully what characters are being sent - past
experience with ANother OS gave problems in a past life (nothing to with
scanners) when the standard serial port handler tried to (MIS)interpret
certain control characters as flow control - hopefully the scanner will not
send anything to provoke it but ...

2/ The above discussion assumes you choose a scanner whose output has
already been decoded - it is possible to buy scanners without decoders but
obviously you are getting into much murkier waters with both hardware and
software issues to deal with. I assume you are not going there...

3/ Much of the 'real' work with applying scanners actually concerns
analysing how they will react with their environment - hence the many types
including wireless, ones with keyboards and memory and so on. Not really a
Linux issue but all of these factors may add constraints and how they all
interface to computer system is anybody's guess until you start working
through it.

Printers

Curiously this is also a strange area. It is possible to persuade most
'everyday' printers (laser, dot matrix, inkjet) to print barcodes with some
suitable software drivers - what is available in Linux flavours I don't
know. Before getting too heavily into that you also need to consider whether
it is useful to have a barcode printed on A4 (or similar) paper. Also the
quality of the image depends on the printer technology. Obviously this
depends on your requirement but in many cases people need 'small' one-off
labels. In which case there are very few (I think I found 2 on a quick
search I did a while ago) manufacturers. From memory I think they were
reasonably OS agnostic, providing the 'userware' sent them the requisite
strings of info to print through the normal printer ports. (You will see
they offer certain off-the-shelf  software package options for quick
printing but these are generally only useful for instant 'type and print'
whereas bar coding systems usually tie up with warehouse database or similar
systems.) For a starting point look at www.printronix.com

Moral - As with the scanners - start with the analysing the user and
environment requirements - worry about Linux versus ??? later.

----------------
In summary - start with the 'environmental' requirements - then consider
what software systems you interface - find some suitable scanners and
printers - if you have any choices of OS left at that stage start checking
out your Linux versus ?? options.

Hope this helps - if you have any further queries or you would like me to
dig a little deeper, please send me an e-mail.

Regards
Dave (Elliott)


----- Original Message -----
From: "Guy Edwards" <guy_j_edwards@hotpop.com>
To: "MAILING LIST" <gloucs@mailman.lug.org.uk>
Sent: Wednesday, April 30, 2003 12:04 AM
Subject: [Gloucs] barcoding


> Pretty obscure this one
>
> Does anyone on the LUG have any experience of using barcode readers
> and/or barcode printers under Linux? (like, are they a nightmare to
> setup or pretty simple?)
>
> Guy
>
> --
> Guy Edwards <guy_j_edwards@hotpop.com>
>
>
>
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