Barcode Scanners and Automated Data Collection (ADC) Basics
By: Dave Piasecki
Automated Data Collection (ADC), also known as Automated Data Capture (ADC), Automated Identification (AutoID), Automated Identification and Data Capture (AIDC), and by many as just “Barcoding” consists of many technologies including some that have nothing to do with barcodes. Voice systems, RFID, OCR, pick-to-light, laser scanners, CCD scanners, hand-held batch and RF terminals, vehicle-mounted computers, and wearable computers are all part of the ADC picture.
The fear of six-figure project costs often prevent many small to mid-sized manufacturers and distributors from taking advantage of Automated Data Collection (ADC) technologies. The key to implementing cost-effective ADC systems is knowing what technologies are available and the amount of integration required to implement them. Applying this knowledge to the processes in your operation will help you in developing the scope of your project. Limiting your project to or prioritizing by those applications that have a high benefit/cost ratio will allow you to apply these operational improvement technologies within a reasonable budget. For example, adding a keyboard-wedge bar-code scanner to an existing PC or terminal in a production or warehouse area is a very low cost method for applying ADC to existing shop-floor reporting and shipping applications. This type of hardware is inexpensive and the only real programming required is that needed to add a barcode to the form (work order, pick slip, etc.)
There are two major categories of barcodes, one dimensional (1D), and two dimensional (2D). 1D barcodes are the ones we are most familiar with and consist of many different symbologies including UPC, Code 128, Code 39, Interleaved 2 of 5, just to name a few (there may also be variations within a specific symbology). The symbology you use may be dictated by supply chain partners through a standardized compliance label program or, if only used internally, can be chosen based upon specific application (tip: if looking for a flexible symbology to use internally on documents, labels, license plates, etc. you will find Code 128 a good choice). 2D barcode symbologies such as UPS’s MaxiCode (shown right), are capable of storing more data then their 1D counterparts and require special scanners to read them. Although I would expect to see continued growth in the use of 2D barcodes, most warehouse and shop floor applications will continue to use 1D symbologies simply because the technology is less expensive and you generally only need enough data in the barcode to access the associated records in your inventory system database. The 1D codes are very capable of accomplishing this. If you’re interested in more detailed information and specs on barcodes I recommend getting a copy of The Barcode Book by Roger C. Palmer.
Laser or CCD
There are primarily two technologies used to read barcodes. Laser scanners use a laser beam that moves back and forth across the barcode reading the light and dark spaces. Laser scanners have been in use for decades and are capable of scanning barcodes at significant distances. CCD (charged coupled device) scanners act like a small digital camera and take a digital image of the barcode which is then decoded. CCD scanners offer a lower cost but are limited to a shorter scan distance (usually within a few inches, however, the technology is advancing quickly and devices with longer scan distances are becoming available). Because of the scan distance limitations, users in a warehouse environment will likely find laser scanners to be their best choice however for applications were barcodes are read from documents – such as in a shop-floor production-reporting application – CCD scanners should work fine.
Autodiscrimination describes the functionality of a barcode reader to recognize the barcode symbology being scanned thus allowing a reader to read several different symbologies consecutively. Most scanners come with this functionality and also allow you to program them to read only certain symbologies (this prevents someone from scanning the wrong barcode when multiple barcodes are present).
Keyboard-wedge scanners connect between a computer keyboard and the computer and send ASCII data to the computer as if the scanner were a keyboard. More simply put, the computer doesn’t know that a scanner is attached and treats the data as though it were key strokes from the user. The advantage of this is that there is no need for special software or programming on the computer. In its simplest application you hook the scanner up, make sure the curser is in the correct field, scan a barcode containing the data you need such as a work order number, an item number, or a location, and the data will immediately appear in the field on the screen.
Although this type of application can prove to be very useful and essentially works right “out of the box”, you will find that by taking advantage of the programmable features of some devices you can take this functionality much further. This is where it gets a little confusing as the programming and functionality is a little different based upon the hardware and software you purchase. Some keyboard-wedge scanners have built in programming functionality, while others are programmed on a separate wedge decoder, and there is also PC software that can perform tasks related to the data input from a scanner. The good news is that you don’t need to be a programmer to use this functionality. If you have ever worked with macros you’ll easily understand this type of programming. What most of these programs allow you to do is to parse data from a barcode (allowing you to put several pieces of data in the same barcode such as item number and quantity, or customer number and shipping method) and also add keystrokes not included in the barcode such as tabs to move between fields, default data, function keys or enter keystrokes to complete transactions.
Keyboard wedge scanners offer a low cost entry into the world of automated data collection and can provide increases in accuracy and productivity in many stationary data entry applications. There are also wireless versions of keyboard wedge scanners available.
Fixed Position Scanners
Fixed position scanners are used where a barcode is moved in front of the scanner as opposed to the scanner being moved to the barcode. Applications include grocery check out counters and automated conveyor systems. Many fixed position scanners are omni-directional which means that the barcode does not have to be oriented any specific way to be read.
Portable computers come in a vast variety of designs with varying levels of functionality. I must admit that I am somewhat disappointed in the lack of progress made in portable terminal design, especially with hand-held units. If you think 386 processors, DOS operating systems, and monochrome displays are ancient history you better think again as these are the specs of many of the hand-held portable data collection devices available today. On the plus side, costs have come down over the years and I’m hopeful that more quickly evolving technologies being developed for devices such as PDAs will soon make portable data collection terminals smaller, lighter, and more functional.
Batch versus RF
Batch terminals are used to collect data into files on the device and are later connected to a computer to have the files downloaded. RF terminals use radio frequency waves to communicate live with the host system or network. While batch devices were heavily used in the past and still have viable applications today, the introduction of wireless standards has made RF technology much more affordable and easier to maintain and implement.
As previously mentioned, I have been less than impressed with advances in hand-held devices. I should also say that I have a lot of problems with the basic nature of hand-held devices themselves. First of all, “hand held” implies that you will be using one hand to hold the device. Well, in most warehousing and material-handling environments this is a problem since that hand can no longer be used to handle materials or operate controls of material-handling equipment. In addition, hand-held terminals generally have very small LCD displays that are usually difficult to read as well as very small, confusing keypads that are difficult to enter data into. This doesn’t mean that these can’t be valuable tools in your operation, only that you need to be sure to consider all the factors when implementing this type of technology. Hand-held devices often come with integrated bar-code scanners (as shown) however, they can be used without a scanner or with a separate scanner.
The standard hand-held device design (like that shown) have little use in a warehouse outside of maybe a cycle count program. Instead, use the pistol-grip models which allow your workers to more quickly holster the device between scans to make use of both their hands.
Keep the prompts as simple as possible. The prompts should show only the bare minimum amount of data necessary to perform the task.
Minimize or eliminate data entry on keypads. As I said before, the keypads on these devices are difficult to use especially with alpha characters. Limit data entry to numeric data as much as possible and also eliminate the need to have to enter tabs or enter keys.
Vehicle-mounted devices have several advantages over hand held devices including larger screens (even up to full sized screens), larger keypads similar to a standard keyboard on a portable computer, and you can’t drop, loose, or forget to charge them. You’re also more likely to find GUI user interfaces (Windows) on vehicle mounted devices. When using a full-screen vehicle-mounted device, integration can be much simpler as you can use your existing programs designed for desktop computers (although you should still consider simplifying the screens). Obviously you need to be performing tasks using some type of a vehicle (lift truck, tug, cart, etc) to use a vehicle-mount device. Generally, vehicle-mounted devices use a separate wired or wireless bar-code scanner to input data. Tips for using vehicle-mounted devices are similar to those for hand-helds (simple prompts, minimize data entry) but you should also consult with your vehicle manufacturer for recommendations on where to mount the device to ensure safe operation of the vehicle.
Wearable systems will likely have the most growth in coming years. Currently offerings in wearable systems are limited and include devices like Symbol’s WS series (nicknamed the Gladiator) that is strapped to the wrist/forearm and uses a small ring-type laser scanner for reading barcodes, or the Talkman from Vocollect which is designed for voice systems (more on voice systems below). Wearable systems provide the functionality of hand-held devices while still allowing workers to use both hands. I should caution you that several hand-held manufacturers have taken their hand-held devices, put them in a fanny pack, connected them to a voice headset or ring scanner and call them a “wearable system”. While technically this is a wearable system, I personally would not want to carry around the added bulk and weight of a device designed with an LCD display and keypad for 8 hours a day just because the manufacturer didn’t want to make the effort to design a wearable-specific device.
. . .
Integration of ADC Technology
While hardware costs of ADC equipment continue to come down, the cost of integration will often prove to be the project buster. Software and Integration costs will often be several times the cost of the hardware, especially in smaller operations where only a few devices will be used.
Integration of ADC technologies is also far from standardized. For example, when implementing an RF system with portable terminals, one integrator may create a program on the terminals that will write directly to the file on the host system, another may create programs on a separate server to do this, another may write or modify a program on your host system and use terminal emulation software, and another may use a screen mapping tool to reformat an existing program to be used on the portable device. Make sure you do your homework and talk to several integrators to ensure you are getting the best solution. Also make sure you participate heavily in equipment selection and program/process design (prompts, data input) to ensure you get a system that provides the highest levels of accuracy and productivity.
There are also integration tools available that allow non-programmers (you will need some pretty good computer skills though) to integrate these technologies with host systems. These tools will not have the functionality and flexibility of a good custom written program but may be adequate for simple applications. Warehouse Management Systems (WMS) often come with interfaces to specific ADC equipment. If your looking to add ADC to your warehouse you may want to first look at a WMS
One of the biggest mistakes made when developing an ADC project is that people approach ADC as an “all or nothing” project. The end result being that the when the project is quoted it tends to come in too costly to ever get implemented. There is rarely significant financial benefit to using the “big bang” approach to ADC projects, so start small with the processes that can best benefit from the application of ADC and add on other processes later.
The entire article is located here: http://www.inventoryops.com/ADC.htm