barcoding in alpha five part 2
Barcoding in Alpha Five is easy - Part II -
Selecting your equipment
This is the second of what will be
three articles directed toward integrating barcodes in Alpha Five. This
article will discuss how to select your equipment for both the scanning and the
printing of barcodes. The first article, published in July 2002, gave
detailed information on setting up your Alpha Five application. If you
have not reviewed it, please consider doing so now. The third article, due
in October, will demonstrate the use of a portable data collector and how to
setup, capture, and upload the data into Alpha Five.
Before we delve in to the heart of
the article, a few acknowledgements are in order. First, my apologies for
the delay in the publishing of this article. It was originally slated for
the August edition, but with the release of Alpha Five Version Five, a special
edition of the newsletter pushed back the article. Certainly a worthy
trade off, as we were all so eagerly awaiting Version Five!
I'd also like to take a moment to
point out that, while this article does relate to Alpha Five, Part II of the
articles has very little to actually do with Version Five! Barcoding
requires that, sooner or later, you purchase some equipment, so I felt an
article aimed at the equipment that is needed was in order!
Lastly, there are hundreds of
manufacturers who offer variations of the devices being described below.
All offer the garden variety of the following barcode equipment , and you are
welcome to purchase your equipment from anyone you choose. In order to
present this equipment to you in a fairly consistent manner, I have
acquired permission from Worth Data to feature their equipment in this
article. I have purchased several units from them, and have found that
they, like Alpha Software, offer excellent quality product and back it with
exceptional technical support. I'd like to take a moment to thank Worth
Data, and especially Tami Ball, for making the depth and detail of this article
possible! Tami Ball, who works with Worth Data, has also contributed to
the actual content of the article, and has briefed me on some of the latest
technological advancements in the industry.
It is important that you, the
readers, understand that Alpha Software and Worth Data are not affiliated in any
way, and neither company is receiving consideration from the other. Please
understand this means there are no discounts or promotions from either company
with regard to the other company.
As you read this article, you will
notice that pictures are used to better illustrate comparisons. These
pictures are the equipment that is currently available from Worth Data. If
you wish more detailed information on any product, simply click on the
corresponding picture to go directly to the Worth Data website page that
corresponds to the device. The page will open in a separate window,
leaving the article window open in the background. If you wish, you may
also visit their website at http://www.worthdata.com/.
Let's get started...
The equipment used falls into two
basic categories; scanning (i.e. input) and printing (i.e. output).
SCANNING
requires a device to read barcodes. There
are five primary properties you need to evaluate before purchasing a
scanner.
1) The first
consideration is the density of your barcode. Below is a chart that
illustrates the differences in barcode densities. The higher the density,
the better the quality printer you need, so you can pretty much forget about
using an inkjet or a dot matrix to print a high density barcode. Some
models of barcode scanners are also sold to meet certain specifications for
barcode density, and this is further discussed in section 4, which covers
scanner properties. (By the way, CODE128 in the illustration below is
another of the many barcode formats that are available!)

2) The second consideration is how
do you want to hook up the scanner to your computer? There are three
possibilities.
The first is the most common, which is
using a Y cable to send the data from the scanner into your PS2 keyboard
port. This method is commonly called a "Wedge" and works well with all
desktop computers as they have external keyboards. It does not work with
notebook computers when using the keyboard that is built in to the unit.
As shown in the illustration below, the Y cable is plugged into the computer in
place of the keyboard, and the keyboard and scanner are plugged into the other
end of the Y cable. The data from the scanner is then dumped into the
keyboard buffer as if it was typed in!

The second option is to use the
computers serial port. This is more commonly done with notebook computers,
but can also be used on a desktop computer. The scanner is plugged into
the computers serial port, a small program running on the computer (once called
a TSR) interprets the data from the serial port, and drops the data into the
keyboard buffer. Worth Data sells a utility called Portkey for this very
purpose.
The third option, USB, is available
for those computers running Windows 95 OSR2 (Windows NT does NOT support USB!)
and above. The computers must also have USB ports available. (USB
ports can be installed on any computer, provided they have a slot available for
the USB card.).
3) Once you determine how you want
to hook up the scanner, you need to determine if you need a separate decoder, or
if the decoder circuitry is built into the scanner
itself.

Most of the more durable scanners plug
in to a decoder, which in turn plugs into the computer via the methods discussed
in section 2 above. The scanners come with what is called an RJ-45 plug on
the end of the cable. Those who are familiar with networking will quickly
recognize this plug as the standard used with category 5 cable. To those
not familiar with networking, this plug looks very much like the ones used with
today's phones, except this plug is much larger and has eight wires instead of
the four used in the telephone industry.
4) The fourth consideration is what
design of scanner do you need. While there are several designs available,
we'll just look at a those that are most common.
This CCD scanner is handheld, as shown
below. The scanner has a range limit of just a couple inches, so it must
be very close to the barcode when it is scanned. This type works very well
with UPC-A barcodes because they are limited to 12 digits. Because CODE39
barcodes can grow to unlimited lengths (based on the number of characters in the
field being barcoded), care must be taken that the barcode can never exceed the
size of the head of the scanner, usually around 3 inches. The CCD scanner
can easily be identified by it's blurred red output.

The "Long range" CCD scanner is
relatively new on the market. Actually, I was unaware it existed until
Worth Data brought it to my attention! It is a good compromise between the
CCD scanner described above the more expensive laser scanner described
below! It can scan from about 7-8 inches away, reads barcodes of about 5
inches in length, and the model offered by Worth Data REQUIRES NO SEPARATE
DECODER, as illustrated in section 3 above. It still produces a blurred
red output, but less so than the atypical CCD scanner. Hence, it is easier
to aim at the barcode.

The laser scanner differs from the CCD
scanner, and consequently costs more. This type of device can read very
long low density barcodes from several feet away, and can read 5 inch long high
density barcodes from several inches away. It is very common in retail
stores and can easily be identified by its crisp laser output, a straight red
line.

The wand is less common, but can handle
slightly longer CODE39 barcodes than a CCD scanner can. It works
especially well in situations where barcodes are close together, such as on a
small label, and it is more compact than other handheld scanners. A wand
is also less expensive than it's three counterparts shown above. The scan
is accomplished by dragging the tip of the wand across the barcode. It can
be dragged from left to right, or from right to left, but it must be dragged at
a consistent speed and at approximately a 45º angle. As a result, new
users find it rather cumbersome for the first few scans, but then quickly
adapt!

It should be noted that the four devices
above all come in switched and non-switched versions. That is, either the
scanner is on all the time, or it is activated by the push of a button on the
device. Personally, I'm partial to the switched types. They help
avoid erroneous scans, and save battery power when used with cordless devices
like the one we will be reviewing in part III of the series on
barcodes.
The last unit is the card scanner.
This type of device is commonly used with membership sign in programs, or
punching in and out from activities. They are similar to those that are
used for credit cards, but they read barcodes rather than magnetic
strips!

5)
Finally, the equipment used for the input (scanning) of barcodes falls into two
primary categories: Portable and Non-portable. If you are new to
barcoding, my recommendation is that you work with non-portable equipment until
absolutely necessary. Non-portable is a lot easier to configure,
less-expensive, and will give you the foundation you need to start working with
portable equipment! I am including this section for comparative purposes
only.
Portable equipment is available in both a wired and a
wireless format, the difference being in how it transfers data to and from the
computer on which your application is running.
Portable
wired equipment includes scanning and printing equipment. The scanners
in this category, while completely portable, are usually used to collect data,
but must be dropped in a cradle, or plugged into a cable when the user wants
to download the data into an application. Printers in this category are
usually used with a portable data collector to print labels anywhere in, say,
a retail store or warehouse, without the limitations of wires to tether the
user. Below are examples:

Portable
wireless equipment differs from portable wired equipment in that the unit
never need be dropped in a cradle, or plugged into a cable, to download the
data. It can transmit a single record or field at a time, or can
transmit it's entire payload to any computer equipped with a receiver, and
within its transmission range.

Non-portable equipment is wired, at all times, to the
computer that is running your application.
This should
give you enough information to start shopping for scanning equipment. As
many readers are new to barcoding, I am including instructions to set you up
with a very basic wand scanner, which you can probably pick up on EBay for a few
dollars, usually under $20! Click here for
details!
PRINTING can be done on a wide
variety of printers. You can use a laser, inkjet, or dot matrix to print
barcodes, but of the three, laser is the best as is scans better and does not
smear as easily. Most printing is done on some form of label, and there is
a wide variety of label sizes available from Avery and it's competitors.
The downfall to using these labels is that there is a great deal of waste.
If your intention is to use these labels, take a look at the article titled
"Define a Starting Position for Labels" in the July 2002 newsletter. It
may save you some stock.
Better
still, if you intend to print a lot of labels on a regular basis, consider a
THERMAL TRANSFER or DIRECT THERMAL label printer!
Direct thermal is the cheaper of the two technologies, but
not by much. The label stock is also a little less expensive. Direct
thermal printers use heat sensitive label media that reacts to the heat from the
printer head. It does not use a ribbon. The downside to direct
thermal is that the labels react to light and heat, and change color when
exposed to either. The same technology is used with most receipt printers
at Home Depot, Wal-Mart, and other retailers. Leave the receipt exposed
and it turns brown and becomes illegible after a short period of
time.
Thermal transfer, while slightly higher in price, produces
a superior label. There are two configurations for this
printer.
The first
is to use plain paper labels (which do not react to heat by design!) with a
wax-based ribbon in the printer. This is the less expensive setup, and is
geared toward a one use application in much the same way as the direct thermal
printer is intended. The labels do not change color to the extent that
direct thermal labels do, but the wax based printing can smudge if you press
your finger against it for a minute or so and then rub them.
The second
configuration uses a polyester label and a resin based ribbon. This
configuration is more expensive, but resists limited exposure to moisture,
grease and dirt, and is better suited to applications where long term labels are
required.

These
printers hook up to the computer in the usual manner, but are most often
attached to the serial port. They use the typical Windows printer
driver. Some printer drivers tend to produce slower print speeds, so
you'll want to take this into consideration when shopping for the printer.
Faster printers are more expensive, generally speaking, but print 6-8 inches per
second. The moderate priced units usually print 3-4 inches per
second.
Expect to
spend some extra time getting your labels to print just right, and be sure to
TEST YOUR BARCODES WITH A SCANNER before distributing them!
In the next
article, we'll take a look at Worth Data's Tricoder unit, and review how to
collect and transfer data into Alpha Five with this exceptional
device!
All
illustrations and images ©Worth Data All rights reserved.
Illustrations and images were used with permission.