Re: Help with bar code

Hi Al,

Sorry for not getting back to you ealier, but here goes on further
explaining what you need to know.

As much mystique as there appears to be with barcode technology, it isn't
that bad.

There is no setup required between Access and the barcode scanner itself.
All a scanner does is read the barcode label, translate it to ASCII and
display the encoded ID on the screen through whatever interface you are using
(i.e. serial, keyboard connector etc.).

Selecting a Barcode Scanner
==================
As I mentioned in an earlier post, there are several types of barcode
scanners that you can purchase. If the user doesn't require mobility, then I
suggest purchasing a PS/2 model with a Y-connector. This will all both
barcode scanning capability and the ability to type in text. If the user
will only have one screen for input and doesn't require the ability to add or
edit records, ditch the keyboard.

If they need to move about, such as in a warehouse setting, then look at a
wireless model. The issue with these is that they can run into interference
issues (always get a demo in your environment first) or require base stations
set up depending on the square footage of the operation.

Barcode Encoding
===========
Most people can get away with using Code 39 or Code 128 (I usually use the
later). In both of these cases, I tie this code to an identifier to one of
my Access table identifiers (usually a primary or composite key).

A barcode system at its roots is nothing more than a catalog system. The
link between your Access application and the barcode is through the barcodes
that are printed either from your application or a third party tool such as
BarTender. As I mentioned before, the only information encoded onto the
barcode label itself is an identifier (i.e. primary key) that links the item
that the label is attached to, to a matching item in your database.

So how does this work?
===============
Now that we now that the barcode label provides the link between the
inventory item and the Access application storing a virtual record of one or
more of said items, we can see how we use this as part of the application.
We'll walk through this in a step by step manner.

1) The developer would create a form for capturing the scans. I suggest
minimizing the number of fields on the form and if speed is not a
requirement, create a small form with a single text box for capturing the
barcode (you'll see why in a minute). Make the text box modal so that it
cannot remove the focus until the user scans a label, or presses a Cancel
button.

2) Create a label in BarTender (or whatever application you have handy) with
some text (doesn't matter what but I suggest alpha numeric). While you are
creating the label, you should see an option to set the barcode to a
particular type (i.e. Code 128).

3) Referring to your barcode scanner manual, there will be instructions on
how to determine the default encoding scheme of your scanner. Usually it is
Code 39, it is usually easy to change. Most allow you to get into a
programming mode where you can set up the options by scanning barcodes in the
manual.

4) Open your new form and with the barcode scanner plugged in, scan the
barcode. Viola. Provided that you have configured the barcode scanner to
read the same encoding as the label, it will translate the many bars of the
label into ASCII in the text box of our form.

Now why did I suggest that you minimize navigation in your form?

One of the biggest pains with barcode wedges (that is the term refered to
ones that are plugged into the keyboard), is that regardless of what
application you are in the barcode scanner is still active and will place
text wherever the cursor is. That's right, it doesn't matter if it is
Microsoft Word, Notepad, Outlook, blah, blah, blah. If the application can
accept text, the barcode scanner will write to it.

How do I avoid this?
=============
This is really the only difficult task you will face is ensuring that it
writes to the correct location, hence the limiting of navigation in a barcode
scanning mode. The use of modal helps since you can limit the possibility of
writing to a totally different field.

The second thing I usually do is create events for:
- detecting when new text has been entered; I create a regular expression to
check the text being scanned in. I always have a predetermined label syntax
so that I can determine what is an inventory label and what is the label from
a bottle of Coke that someone thought would be fun to test the scanner on.
For example, I have used the initials of the application name followed by the
primary key identifier (autonumber with unique constraint) or if I track
inventory types, I will use type codes (for example, CER for cereal or SD for
softdrinks).

- parsing the text. Once text has been entered, parse if necessary and query
that against a recordset of items in your database. I suggest matching the
text against a regular expression. Since inventory systems can grow and it
slows matches, this is where partitioning your barcode items into different
types can really help.

I hope that provides a bit more detail into what you are looking for.

Lance

"Al" wrote:

>
> thank you for your response. what I need to realy Know and I hope that
> someone can answer is that how is the setup between access and the scanner
> takes place? Say I create a form bound to a table in access , and the field
> that stors this data, has the focus. now how is the scanner writes to it when
> someone scans? is there a setup on the scanner to make it scan to access? do
> I need to do anything in access to recognize the scanner? I need some one to
> clarify this for me. thank you.
> Al
> "postman" wrote:
>
> > I too need to implement barcodes at some stage, so am interested in
> > responses to this thread.
> > As much as I understand, a BC scanner is interpreted by the os as "like" a
> > keyboard input, as if you where typing in numbers.
> > To say that wherever your curser has focus would be where the data is
> > inputted, be it in any text application. Of course I have only just started
> > looking into this, I have a cheap scanner from e-bay it reads & prints codes
> > to a receipt printer when connected to it ok, but I have yet to hook it up
> > to Access.
> > I'll stay tuned
> > Thanks.
> >
> >
> > "Al" <Al@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> > news:C64CCF25-0934-43A9-A110-D8F7393E3ECF@xxxxxxxxxxxxxxxx
> > > Thank you very much this was very helpful. I learned from both replies.
> > > However, I still do not understand, how the scanning works with access.
> > > what
> > > I mean is this. we are going to have 2 scanners to scan medication bar
> > > code
> > > that is already on the containers, when the scanners scan the bar code how
> > > does it get into access. what are the necessary steps that I need to do to
> > > capture what the scanner scans?
> > > thanks
> > > Al
> > >
> > > "LTofsrud" wrote:
> > >
> > >> Hi Al,
> > >>
> > >> I have been on several projects that have required bar code technology
> > >> and
> > >> here are a couple of suggestions that you should consider after you have
> > >> done
> > >> a bit of research:
> > >>
> > >> 1) Most people adopt the Code128 format for simplicity and it is usually
> > >> more than enough for most people
> > >>
> > >> 2) A good vendor that I have used is for all of my projects is Seagull
> > >> Scientific(http://www.seagullscientific.com/aspx/welcome.aspx). They
> > >> make a
> > >> product called BarTender that is great for creating barcodes. I have
> > >> used
> > >> different versions of their software and depending on your needs, I have
> > >> found it excellent for both small VB/Access applications where I used it
> > >> for
> > >> just creating a format that can print single label to sending batches
> > >> through
> > >> a command line. In Enterprise situations where you need a client server
> > >> or
> > >> n-tier solution, I used their Enterprise edition to host and send large
> > >> batches of labels to a dedicated barcode printer. Personally, I strongly
> > >> suggest staying away from the free fonts that you find on the web. I had
> > >> nothing but problems with them.
> > >>
> > >> 3) If you are thinking of using a 'regular' printer for sending your
> > >> print
> > >> jobs to, purchase some Avery or similar labels and test them first with
> > >> whatever barcode hardware you are going to be using. Sometimes not all
> > >> of
> > >> the inks can be read by the reader.
> > >>
> > >> 4) If you are only using a single entry point for barcode reading, you
> > >> can
> > >> go the easy route and use a barcode wedge which allows you to attach it
> > >> to
> > >> the keyboard port (there is also a Y-splitter you can use so that you
> > >> don't
> > >> lose the keyboard altogether). If the user needs mobility (say for
> > >> getting
> > >> up high or longer distances than the tether will afford), then look at
> > >> either
> > >> a wireless device or a handheld device. A great wireless device that I
> > >> have
> > >> purchased in the past is the Symbol wireless Phaser units (P370 I think).
> > >> May be a bit of overkill, but you can make that decision. If you are in
> > >> a
> > >> warehouse type of situation where they will be gone for extended periods
> > >> of
> > >> time, try a handheld PDA such as the Intermec 700 series. I did this on
> > >> one
> > >> project where they then placed the PDA into a docking device with a modem
> > >> and
> > >> they transferred it via modem to an Access database. Of course it adds a
> > >> bit
> > >> of extra coding since you need a UI and backend on the PDA (Intermec
> > >> offers a
> > >> software development package called MCL but I would stay away from it;
> > >> easy
> > >> but it was Alpha quality when we used it - go with AppForge Crossfire
> > >> instead).
> > >>
> > >> Thats about all I can think of for now, but while it is really cool
> > >> developing applications that use this technology, it can also be
> > >> frustrating
> > >> if you don't do the research ahead of time.
> > >>
> > >> Let me know if you have any other questions in regards to my post.
> > >>
> > >> Lance
> > >>
> > >>
> > >> "Al" wrote:
> > >>
> > >> > My company decided to incorporate a bar code system into our access
> > >> > database.
> > >> > I have been an access programmer for long time, but I have never worked
> > >> > with
> > >> > bar code. Does any one know how it works with access? Is there a
> > >> > literature
> > >> > on how to incorporate this into access database. I work in access2002
> > >> > Thanks
> > >> > AL
> > >> >
> >
> >
> >
.