Barcode Scanning Education

Linear Imagers

Linear imaging is a fast growing scanning technology. The scanner emits a large rectangle which designates the scanning area allowing the barcode to be read from varying angles rather than only straight on. The newer linear imagers have the ability to scan barcodes at varying distances. They are still a little pickier than laser barcode scanners when it comes to reading distances, though.

Laser Barcode Scanners

Laser scanners are the most popular scanners. They emit a single line making aiming easy. Laser scanners also scan very quickly and can work from distances as close as a 1 inch all the way up to 24 inches.

Retail

Retail scanners are used in point of sale applications. On-counter scanners usually have their own stands or are built with a stand. It is designed to “wake up” when a barcode is waived in front of it. In-counter scanners are built into the retail counter and allow for high-volume scanning. They can also weigh items and deactivate security tags.

2D

2D Scanners work very similarly to an imager. The key difference is the ability to read 2D barcodes. A 2D barcode is able to contain a lot of data inside of it. It also has the ability to read partial bits of the data if the barcode is damaged.

Direct Parts Marking Reader (DPM)

DPM barcode scanners have special lighting techniques to read barcodes that are engraved directly on the product. These need a special scanner because there is not enough contrast between the barcode and the background to scan the barcode.

Barcode Slot Reader

Barcode slot readers are used similarly to mag-stripe or credit card readers. Simply swipe the card through the slot to scan the barcode. Typically, these are used in security applications, like access control.

Universal Serial Bus (USB)

USB is now the most common way to connect a barcode scanner to a computer or laptop. There are some major advantages to USB connection options: 1) Typically power is drawn from the source that the device is connected to. This means that no other cables are needed to get power to the barcode scanner. 2) Information scanned is put into a program just like you were typing on a keyboard. Wherever your cursor is blinking is where the data will be entered. 3) Since it is USB, the barcode scanner can be plugged into a variety of devices.

PS/2 or Keyboard Wedge

PS/2 use to be a more common connection type. The PS/2 connection allows part of the cable to be plugged into a keyboard and then the cable splits and plugs into the computer’s keyboard port. This is why it is called keyboard wedge. PS/2 barcode scanners input the data into an application the exact same way that it would if you were typing on a keyboard. Just like USB, the PS/2 cable will draw power from the computer. USB has become more popular because it is faster and you work with less cables.

RS-232 or Serial

Typically this is a 9-pin cable that plugs into a computer or some other type of host. RS-232 cables usually require an external power source. The data from RS-232 is not received as keyboard input. The data is received as serial data and will require “mapping” the data in order for information to be put in the correct fields of an application.

Bluetooth®

A growing trend in barcode scanning is to go cordless. Bluetooth® is now the most common form of cordless communication. When a scanner uses a Bluetooth® connection, the device is paired with a base station. This works similarly to the way a cordless phone works. The base that the phone sits in actually provides the link between other phone lines and charges the cordless phone.

Some people have concerns that Bluetooth® is not secure and that there are now too many devices deployed with it. A major advantage is that Bluetooth® devices can communicate with each other.

There are 3 classes of Bluetooth® radios:
• Class 3 radios - have a range of up to 1 meter or 3 feet
• Class 2 radios - most commonly found in mobile devices - have a range of 10 meters or 33 feet from the base
• Class 1 radios - used primarily in industrial use cases - have a range of 100 meters or 300 feet from the basembologies available
The two classes that you see in barcode scanners are Class 1 and Class 2.

Radio Frequency (RF)

Works very similar to Bluetooth®, but RF uses different radio frequencies to “talk” to a base station. One of the key differences is that RF has a longer read distance than Class 2 Bluetooth Radios®, but not as far as Class 1 Bluetooth®. RF is also a more closed solution; it does not allow pairing up with other devices like printers or mobile computers.

A big factor in making the decision...

about which barcode scanner to purchase should be the conditions the unit must endure. Whether you are using your barcode scanner in a carpeted space or using your handheld barcode reader in a warehouse or manufacturing environment, your choice of barcode scanner is critical. Units designed for the carpeted space are sometimes called commercial grade, value-line, or general purpose. Units for manufacturing or warehouse space will be called rugged or industrial scanners.

Commercial grade barcode scanners are...

designed for environments such as retail or office space. These scanners will have a lower drop resistance that is around 5-ft. The drop resistance refers to the height that a device can be dropped on each side 6 times without breaking. The other large difference that you will see is IP rating. The IP rating refers to the amount or level of water or dust particles that the barcode scanner is sealed against. On the commercial grade barcode scanners you will usually see a rating of 42. The first number refers to object resistance. The 4 means that it is protected against small solid bodies. The second number refers to water. The 2 means that the unit is protected against dripping water even tilted 15 degrees vertically.

Industrial handheld units are...

designed to be used and abused. They are extremely rugged and designed to be in manufacturing or warehousing applications. Industrial handheld scanners have a drop resistance of 6.5-ft. and an IP rating of 65. The 6 means that barcode scanner is protected against all dust penetration. The 5 means that the unit is protected from water jets from all directions.