For reading bar codes into an Access application, you have two
choices.
Most bar code readers are available with one of two output options.
The first option is called "Keyboard Wedge" output where you unplug
your keyboard, plug the bar code reader into the keyboard port on your
PC and then plug your keyboard into the bar code reader. This
arrangement makes the bar code reader appear as it it were simply a
second keyboard. Your original keyboard continues to work as normal
however when you read a bar code, the data encoded in the bar code
appears to any application running on your PC as if it were typed in.
The keyboard wedge interface is extremely simple however it has a few
drawbacks. If you scan a bar code, the cursor has to be in the correct
input field in the correct application otherwise you end up reading
bar code data into whatever application has the focus. This can cause
all sorts of potential problems if the cursor is not in the right
place when the bar code is scanned. You also cannot "lock" a textbox
so that the user cannot type in data and force data to come in from
the scanner only.
The keyboard output also is limited in that you cannot modify the data
in any way before sending it into the program that is to receive the
data. For example, if you needed to parse a bar code message up into
pieces or remove some of a bar code message or add in a date or time
stamp you would not be able to with a normal keyboard wedge reader.
The best way to read bar codes directly to an Access application is to
get a bar code reader with an RS232 or "Serial" interface. With these
types of bar code readers, you connect the reader to an available
serial port on the back of your PC. You would then need a program
called a "Software Wedge" to take the data from the bar code reader
and feed it to the application where you want the data to go. The
disadvantage to this approach is that it is a little more complex
however you gain much more control over how and where your data ends
up when you read a bar code. With a Software Wedge, you can control
exactly where the data goes in the target application and you can also
perform all sorts of modifications on the data before it is sent to
the application.
You can also set everything up so that the textbox where the data gets
written is locked so that only bar code data can go into the textbox.
In addition, you can minimize your application and have it running in
the background while you use the PC for other tasks and still have all
bar code data go into the database.
TAL Tehchnologies sells a product called WinWedge which is a Software
Wedge for Windows. For interfacing a RS232 bar code scanner to an
Access application, WinWedge is the best tool available.
Visit:
http://www.taltech.com/products/winwedge.html
for more information about WinWedge.
TAL also sells a very high quality line of bar code laser scanners at
very reasonable prices. All their scanners are available with either
the keyboard wedge output or RS232 output. For scanners see:
http://www.taltech.com/products/bc_reader.html
This web site is also an extremely good place to obtain information
about bar coding in general be sure to look in the Resources section
of the site for a bar code tutorial.