Portable data-collection terminals have evolved from so-called 'dumb' devices that simply read bar codes and pass them on to a computer for processing to highly specialized, sophisticated terminals," says Joe Zvanut, program manager, mobile WAN, for Hand Held Products. "Portable data-collection terminals are now computers and are programmable.
"Every terminal should be designed for one thing -- to make data collection easy, fast, and accurate -- and most of all, portable," he continues.
According to Zvanut, there are three basic ways data-collection devices can communicate information to the host:
* Batch. Data is stored in the terminal for later loading to the host over wire through a physical or optical interface in the terminal's docking station.
* Online wireless local area networks (WLAN). Data collected is sent as it is captured over a low-power, local wireless-data system.
* Online wireless wide area networks (WWAN). Data collected may be transmitted wirelessly using a wide area data-communications network.
Wireless data-communications systems, whether local or wide area, are usually more costly due to the additional infrastructure and equipment required to support them, Zvanut contends.
Before selecting a portable data-collection terminal, advises Zvanut, carefully consider what information will be collected and how important that information will be. Wireless data communications should be considered if the information collected will be time critical, if the user will need online database access, and if the data will be used immediately by other applications.
"Looking at portable data-collection terminals from an application-centric perspective relieves some of the buyer's anxiety," Zvanut says. "Choosing the right device for the application is the end result of conscious trade-offs between 10 characteristics: size vs. weight; more rugged vs. less; high feature/function vs. low; high cost vs. low; and long battery life vs. short."
Zvanut suggests weighing these factors when selecting a device:
* Ergonomics. If the portable device isn't easy to use, simple to operate, comfortable to hold, or interferes with the job at hand, a worker may be reluctant to use it.
* Data collection methods/options. Data-collection terminals offer a variety of data-entry methods, including laser, or noncontact, bar-code scanning, contact bar-code scanning, direct keyboard entry, and pen entry.
* Display size/orientation. Display size and orientation sometimes create more confusion than clarity. In many cases, only three lines of information need to be seen: item number, location, and quantity.
Once it's determined how much information should be displayed on the screen, consider the credibility of the display: Are the characters large enough? Is the character set familiar to the operator? Is there sufficient contrast for the characters to be legible? Is the screen backlit for poorly lighted areas? Can the fields be easily seen by the operator as data is entered?
* Operating environment. If a terminal is not sealed against weather, it can lose valuable data. Harsh conditions can also exist indoors, in places like shipping docks and refrigerated warehouses. Temperature can affect a number of components in a portable terminal, including the battery display and the power supply. As a rule of thumb, terminals designed to survive multiple drops to concrete from relatively high distances (5 ft. or more) are likely to remain in operation longer.
* Central processor. Keep in mind that the objective is to collect specific information, format the data for file updating, and present the information to the operator for action or further input. Choosing portable data terminals with stable, proven CPU platforms may be slightly more costly now, but will produce dividends as application requirements change.
* Other factors. A portable data terminal is rarely, if ever, a complete solution in itself. It needs application software, and it needs to exchange data with other information systems and be integrated into the overall information and control infrastructure.
* Accessories. Accessories facilitate communications between the terminal and the host, and provide a method for recharging batteries. They include docking stations and standalone multiple battery chargers.
* Service and support. The success or failure of a portable data-collection system rests on the reliability of the terminals and accessories, and the level of support received before and after the sale. Service and support, especially for application development, should be near the top of the list of considerations.
* Price. Buyers will find prices ranging from $400 to $5,000. "Experience has shown that some so-called `low end' terminals provide all the features and functionality needed to collect, process, and transmit data."
According to Zvanut, easy-to-use automated data-collection systems that meet a fleet's requirements can be implemented quickly and show a rapid return on investment.
"Choosing a portable data-collection system that can be upgraded and expanded will protect that investment through available options, upgrades, and application extensions," he concludes.