[comp.graphics] Bar Coding

olasov@heathcliff (Benjamin Olasov) (03/13/89)

Hello,


I'm looking for some information on bar-coding, and I'd welcome just about
any kind of reasonably current information on it, from hearsay to first hand
experience to manufacturer's promos.

I'm especially interested in any bar-coding hookups to the AutoCad package,
but, as I said, all info is welcome.

If there's an indication of interest, I'll summarize responses.



Many thanks,


Ben

jcbst3@cisunx.UUCP (James C. Benz) (03/13/89)

In article <6218@columbia.edu> olasov@heathcliff.UUCP (Benjamin Olasov) writes:
>
>Hello,
>
>
>I'm looking for some information on bar-coding, and I'd welcome just about
>any kind of reasonably current information on it, from hearsay to first hand
>experience to manufacturer's promos.

We have an extensive bar-code application here to manage our film library and
our pool of AV equipment offered for rent.  I set the system up using what
are known as wedges to do the actual bar-coding.  The wedge sits on the 
terminal line (RS232) between the terminal and the computer.  The terminal
acts just as it does normally, but whenever a bar code is read with the wand,
the computer sees the code just as though it was typed at the terminal.  The
codes we use are code 3 of 9, and are pre-printed on sticky labels from a 
supply house.  The readers we use were manufactured by a company called Caere
in Los Gatos, CA, phone (408) 395-7000.  The readers themselves cose about
$600 per unit, for a wand type scanner.  I believe they also have counter
type scanners.  The scanner is configurable for several types of bar-codes,
including UPC, using dip-switches.  It  can also be configured to stand
alone, without a terminal.  The advantage to using a terminal wedge are
that if the scanner won't read a code, or you are sitting at a terminal 
without a scanner attached, you can manually enter the code from the keyboard.
Also, computer ports are not tied to a scanner, but can be used for other
applications that do not require a scanner as well.  The software we use
is Informix, with a lot of C.  Since the codes come in exactly as if they
were entered from the keyboard, Informix has no trouble accepting coded
info in any of its modes (Perform, etc).  We don't use any printer software
to print codes, since pre-printed labels are about a penny each, and since
the only software I've seen to print codes prints them about 8 inches long
and 1.5 inches high, too big to stick on a microphone or cable tag, and the
only advantage I can see to printing your own codes is that you can include
some intelligible info in the code itself, but when you consider that the
code can be linked to any kind of data within the computer, just the fact that
a unique code exists for an item is enough for the computer to call up the
complete data set for that item - the idea of a bar code is for the machine
to read it, not the user.  In addition, the bar code wands are set to read
a specific code density (number of chars/inch of code) and since so many
of our items require small code stickers, it is not practical to mix large
codes printed in-house with pre-printed sticker codes which have a very 
high density.  Our code stickers are about 1.5 inches long and 3/8 inch high.
Reliability of code reading depends on whether you use a counter type
scanner or a wand type, with counter type having fewer mis-reads (not error
reads - checksums stop these - a misread is when the code is passed over 
the scanner and nothing happens.) and wand type being very dependent on the
experience of the person using the wand.  Wand scanners read best when held
at specific angles and take some practice to get the right angle and scan
speed programmed into the user's hand circuitry :-}  

Any questions : jcbst3@unix.cis.pittsburgh.edu


-- 
Jim Benz 		     jcbst3@unix.cis.pittsburgh.edu     If a modem 
University of Pittsburgh					 answers,
UCIR			     (412) 648-5930			 hang up!