1. Field of the Invention
The present invention relates to automated data collection systems that collect information from radio frequency identification (RFID) transponders, and more particularly, to an automated data collection system that uses the information encoded in the RFID transponder to control certain network applications.
2. Description of Related Art
In the automatic data identification industry, the use of RFID transponders (also known as RFID tags) has grown in prominence as a way to track data regarding an object to which the RFID transponder is affixed. An RFID transponder generally includes a semiconductor memory in which digital information may be stored, such as an electrically erasable, programmable read-only memory (EEPROMs) or similar electronic memory device. Under a technique referred to as “backscatter modulation,” the RFID transponders transmit stored data by reflecting varying amounts of an electromagnetic field provided by an RFID interrogator by modulating their antenna matching impedances. The RFID transponders can therefore operate independently of the frequency of the energizing field, and as a result, the interrogator may operate at multiple frequencies so as to avoid radio frequency (RF) interference, such as utilizing frequency hopping spread spectrum modulation techniques. The RFID transponders may either extract their power from the electromagnetic field provided by the interrogator, or include their own power source.
Since RFID transponders do not include a radio transceiver, they can be manufactured in very small, lightweight and inexpensive units. RFID transponders that extract their power from the interrogating field are particularly cost effective since they lack a power source. In view of these advantages, RFID transponders can be used in many types of applications in which it is desirable to track information regarding a moving or inaccessible object. One such application is to affix RFID transponders to packages or parcels moving along a conveyor belt. The RFID transponders would contain stored information regarding the packages, such as the originating or destination address, shipping requirements, pick-up date, contents of the package, etc. An RFID interrogator disposed adjacent to the conveyor belt can recover the stored information of each RFID transponder as it passes no matter what the orientation of the package on the conveyor belt. The RFID interrogator may then communicate the collected information to a computer or computer network for further processing by a software application.
A drawback of conventional automated data collection systems is that the conveyance of information from the RFID interrogator to the software application operating on a computer or computer network is independent of the information content. The interrogator generally forwards the collected information to the software application irrespective of the content of the information, and the software application then determines what actions to take with respect to the information. There presently exist many known RFID transponder types having unique data formats and protocols, with each such format and protocol being generally incompatible with each other. More than one type of RFID transponder may be present within the operating environment of a single RFID interrogator, such as a first type of RFID transponder disposed on a truck and a second type of RFID transponder disposed on a pallet carried by the truck. Thus, separate software applications may be used to process the information from each of the RFID transponder types, and yet another software application may be used to distinguish between the collected information and route the information to the appropriate software application for subsequent processing. The use of a software application to provide the routing function necessarily limits the flexibility of the network applications that use the collected information.
It would therefore be desirable to provide an automated data collection system in which the RFID interrogator can convey collected information to different locations, computers and/or software applications based on the information content of the RFID transponder.