|
Bar code data-collection systems fall into three basic types: interactive, batch, and hybrid.
An interactive system consists of one or more portables connected in real time to a computer. In these systems, the central computer manages data collection and verification as the user enters data.
A batch system uses one or more portables to gather data that is stored for later input to a computer. This is the most common and most economical portable system. Batch systems can do only limited validity checking.
A hybrid system is a combination of the two.
Interactive systems have several advantages over batch systems. Almost all systems where bar code hardware is in a fixed location are interactive systems. Advantages include:
Immediate Data Verification: As the user enters data, the user variable responses depending on that validity.
Sophisticated Data Verification: An interactive system can check many more variables when performing data verification.
User Interaction: Interactive systems can give the user better feedback when an error occurs.
Error Reduction: All of the above advantages tend to reduce errors in an interactive system.
Easy Setup: Interactive systems use standard programming techniques and error checking, much like programming for PC's.
Batch systems are generally used with protable readers. They are also used in some fixed-mount systems wher the reader must continue to collect if the computer system goes down. While interactive systems are superior in the ways listed above, batch systems do have some advantages:
Economical for Standard Portables: Portables can be used for batch or real-time applications. On average, setup costs for batch systems are less than half the costs of Radio Frequency systems.
Reliable in Mission-Critical Applications: Since batch processing distributes data collection to stand-alone units, operation is not dependent on the central computer.
Hybrid Systems: Serveral systems combine attributes of both interactive and batch modes. The most common are radio frequency systems and batch/interactive hybrids.
Radio Frequency Systems use RF signals to connect protable readers to a central computer in an interactive manner. This gives the advantages of an interactive system combined with portability.
Batch/interactive hybrids use local batch processing combined with an interactive link to a central computer. These work primarily as interactive systems, but they can function independently for a period of time if the central computer fails.
|
