Abstract:
A method and an apparatus are provided for Radio Frequency Identification (RFID). An RFID base unit is provided that can communicate with at least two different types of RFID tags that are commercially available. Additionally, the RFID base unit can communicate with any number of devices, including but not limited to computer networks, which allow for dynamic access and updates to tailor the RFID base unit for virtually any situation. Particularly, the RFID base unit would be useful in safety and/or security applications to enable and disable automated devices.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to Radio Frequency Identification (RFID) and, more particularly, to employment of RFID tags and devices in automated applications. 
   DESCRIPTION OF THE RELATED ART 
   RFID tags and devices have been around since World War II. The first known usage of RFID tags was by the United Kingdom&#39;s Royal Air Force. The RAF placed RFID tags in their aircraft, so that the Spitfires and other allied aircraft could be distinguished from German aircraft. 
   Over the years, though, RFID tags have become more ubiquitous. RFID tags are commercially available in a wide variety of applications ranging from implanted tags for keeping track of pets to toll tags. Categorically, there are three types of RFID tags commercially available: passive, semi-passive, and active. Passive tags are unpowered RFID tags that utilize radiation or electromagnetic fields in order to function. Active tags have their own power source, and semi-active tags utilize both an internal power supply and absorbed radiation or electromagnetic fields. 
   Referring to  FIG. 1A  of the drawings, the reference numeral  100  generally designates a passive RFID tag that utilizes wave reflection. Typically, the passive RFID tag  100  comprises an antenna  102 , Radio Frequency (RF) Circuits  104 , and an Identification (ID) circuit  106 . 
   The passive RFID tag  100  is, by definition, unpowered. Radiation is received by the antenna  102  and transmitted to the RF circuits  104  through the communication channel  108 . The RF circuits  104  can then de-modulate or processes the signals received by the antenna  102 . The processed signals are then communicated to the ID circuit  106  through the communication channel  110 , where the ID circuit  106  generates an ID number or some other identification signal. Once the ID circuit  106  generates an identifying signal, the RF circuit  104  and the antenna  102  can then transmit the identifying signal. 
   Therefore, by receiving an electromagnetic signal, processing it, and retransmitting it, the passive RFID tag  100  essentially reflects the received radiation. So, by varying the ID circuitry  106  and/or the RF circuitry  104 , each tag, such as the passive RFID tag  100 , can reflect radiation differently causing each tag to be distinguishable. 
   There are a wide variety of applications for RFID tags similar to the passive RFID tag  100 . Typically, tags, like tag  100 , are low cost and robust. However, the physical range and flexibility of tags, like the tag  100 , are limited. 
   Referring to  FIG. 1B  of the drawings, the reference numeral  150  generally designates an active RFID tag. Typically, the active RFID tag  150  comprises an antenna  102 , Radio Frequency (RF) Circuits  104 , an Identification (ID) circuit  106 , and a battery  112 . 
   The active RFID tag  150  is, by definition, powered. Under the circumstance of having a powered RFID tag, there are a larger number of operations that can be performed by the active RFID tag  150 . Signals can be received and transmitted by the antenna  102 , which provides the signals to the RF circuits  104  through the communication channel  108 . The RF circuits  104  can then modulate and de-modulate signals. 
   Because the active RFID tag  150  is powered by the battery  112 , the ID circuits  106  can be operating constantly. The ID circuit  106  can both send signals to and receive signals from the RF circuits  104  through the communication channel  110 . The ID circuit  106  can generate identifying signals or be in active communication with another RFID station. Hence, information contained on the RFID tag  150  can be updated or changed. 
   There are also a wide variety of applications for RFID tags similar to the active RFID tag  150 . Typically, tags, like tag  150 , are flexible and robust. However, the physical range and time of operation, like the tag  150 ( 100 ), are limited. The batteries, such as the battery  112 , will need periodic replacing or charging in order for tags, like the tag  150 , to continue functioning. 
   There are also other types of alternately powered RF tags. Referring to  FIG. 2A  of the drawings, the reference numeral  200  generally designates a passive RFID tag powered by a magnetic field. The tag  200  comprises an inductor  202 , power generation circuitry  204 , a microcontroller  206 , RF circuits  208 , and an antenna  210 . 
   The tag  200  is different, in that a magnetic coupling is needed. When the tag  200  enters into a changing magnetic field of sufficient strength, the inductor  202  couples to the field. The changing magnetic field induces a current in the inductor  202 , which provides current to the power generation circuitry  204 . Power can then be provided to the microcontroller  206  and the RF circuits  208  through the communication channel  212 . 
   Once powered, the antenna  210  can send and receive information with external devices. The microcontroller  206  communicates with the RF circuits  208  through the communication channel  214  to allow for signal transmission and reception. Also, because power can be applied for long periods of time due to the magnetic coupling, it is possible to write data to the microcontroller  206  and to change information when desired. 
   For tags, like the tag  200 , there are a wide variety of applications for RFID tags. For example, tags implanted into pets utilize a tag similar to the tag  200 . These tags are typically flexible and robust. However, the physical range and time of operation are limited. A magnetic field must be provided in order for the tag  200  to function, and providing such a magnetic field can be costly in terms of power consumption. 
   Referring to  FIG. 2B  of the drawings, the reference numeral  250  generally designates a semi-passive RFID tag. The tag  250  comprises an inductor  202 , power generation circuitry  204 , a microcontroller  206 , RF circuits  208 , an antenna  210 , and a battery  212 . 
   The tag  250  is similar to the tag  200 , in that a magnetic coupling is needed. However, only part of the circuitry is powered through the magnetic coupling. When the tag  250  enters into a changing magnetic field of sufficient strength, the inductor  202  couples to the field. The changing magnetic field induces a current in the inductor  202 , which provides current to the power generation circuitry  204 . Power can then be provided to the RF circuits  208  through the communication channel  212 . The microcontroller  206 , though, is constantly powered by the battery  212 . 
   Once powered, the antenna  210  can send and receive information with external devices. The microcontroller  206  communicates with the RF circuits  208  through the communication channel  214  to allow for signal transmission and reception. Also, because power is constantly applied to the microcontroller  206 , it is possible to write data to the microcontroller  206  and to change information when desired. 
   For tags, like the tag  250 , there are a wide variety of applications for RFID tags. For example, tags implanted into pets utilize a tag similar to the tag  250 . These tags are typically flexible and robust. However, the physical range and time of operation are limited. A magnetic field must be provided in order for the tag  250  to function. Providing such a magnetic field can be costly in terms of power consumption. Additionally, the battery  212  may have to be periodically changed or recharged, which can be costly. 
   In each case, the RIFD tags  100 ,  150 ,  200 , and  250  each function in concert with an RFID base unit. Traditionally, RFID base units were tailored for specific types of tags. The RFID base units have also been tailored for specific applications, and have not been necessarily monitored. With the ever increasing utility of RFID tags, employment of a system that is easily monitored and easily established is desirable. Therefore, there is a need for a method and/or apparatus for communicating with a multitude of devices and RFID tags that at least addresses some of the problems associated with conventional RFID base units. 
   SUMMARY OF THE INVENTION 
   The present invention provides a method and a system for securing an external device with an RFID base unit. An RFID base unit is provided that is adapted to communicate with at least a first and a second RFID tag type of a plurality of RFID tag types. An RFID tag then interfaces with the RFID base unit, where the RFID tag is of the first or the second RFID tag types. Once the at least one RFID tag interfaces with the RFID base unit, indicia of engagement, disengagement or other affect on the control or operation is communicated to the external device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
       FIG. 1A  is a block diagram depicting a conventional, passive RFID tag that utilizes wave reflection; 
       FIG. 1B  is a block diagram depicting a conventional, active RFID tag; 
       FIG. 2A  is a block diagram depicting a conventional, passive RFID tag powered by a magnetic field; 
       FIG. 2B  is a block diagram depicting a conventional, semi-passive RFID tag; 
       FIG. 3  is a block diagram depicting a RFID system; and 
       FIG. 4  is a flow chart depicting the usage of an RFID system in a safety or security application. 
   

   DETAILED DESCRIPTION 
   In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without such specific details. In other instances, well-known elements have been illustrated in schematic or block diagram form in order not to obscure the present invention in unnecessary detail. Additionally, for the most part, details concerning network communications, electro-magnetic signaling techniques, and the like, have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the present invention, and are considered to be within the understanding of persons of ordinary skill in the relevant art. 
   It is further noted that, unless indicated otherwise, all functions described herein may be performed in either hardware or software, or some combinations thereof. In a preferred embodiment, however, the functions are performed by a processor such as a computer or an electronic data processor in accordance with code such as computer program code, software, and/or integrated circuits that are coded to perform such functions, unless indicated otherwise. 
   Referring to  FIG. 3  of the drawings, the reference numeral  300  generally designates a RFID system. The system  300  comprises a unified RFID base unit  304 , an RFID tag  302 , a computer network  314 , automated devices  330 , alternate security device  334 , and an Input/Output (I/O) device  338 . 
   In operation, there a number of configurations that can be employed. In all of the systems, the RFID tag  302  communicates with the RFID base unit  304  through an RF link  332 . Depending on the type of RFID tag  302  desired, the RFID base unit  304  is equipped to communicate with any type of RFID tag. 
   At the center of the system  300  is the RFID base unit  304 . The RFID base unit  304  further comprises a field generator  306 , RF circuitry  308 , an antenna  309 , a microcontroller  310 , and an RF Integrated Circuit (RFIC)  312 . The RFIC  312  is coupled to the RF circuitry  308  and the microcontroller  310  through the communication channels  346  and  344 , respectively. The RF circuitry  308  communicates information to and from the RFID tag  302  by utilizing the antenna  309  and the RF link  332 . Additionally, the RF link  332  can be of multiple frequencies to communicate with standard low frequency RFID tags (between 125 kHz to 134 kHz), standard high frequency RFID tags (13.56 Mhz), standard Ultra High Frequency (UHF) RFID tags (868 Mhz to 956 MHz), and standard microwave RFID tags (2.45 GHz). The RFID base unit  304  can also be designed to be robust and powered by a variety of power sources. For example, the RFID base unit  304  can be powered by standard 110 VAC, batteries, rechargeable batteries, power over Ethernet, power over USB, etc. 
   Additionally, the RFID base unit  304  can be constructed using various housings for harsh environments. For example, a basic version, a shockproof version, a high/low temp environment version, a highly acidic/basic environment version, and so forth could be developed. Depending on the type of RFID tag  302 , the field generator  306  can be engaged by the RFIC  312 . Control information is provided to the field generator  306  from the RFIC  312  through the communication channel  342 , and, when desired, the field generator  306  may not be utilized. Such case where the field generator  306  may not be utilized is when the RFID tag is a passive RFID that utilize a reflected wave, such as the tag  100 . The field generator  306  is coupled to an inductor  307  for generating a magnetic field, when indicated, to provide power to a passive or semi-passive RFID tag. However, it is possible to have the field generator  306  deliver control information to a much larger generator with a large power source to generate a magnetic field. 
   Then, based on the configuration desired, the RFID base unit  304  can be coupled to a variety of other devices. To be able to interact with multiple devices, the microcontroller  310  can be flexible. The microcontroller  310  of the RFID base unit  304  can have memory which would include expandable volatile memory, such as Dynamic Random Access Memory (DRAM) or Static Random Access Memory (SRAM) and non-volatile memory, such as Hard Disk Drives and flash memory sticks. Additionally, standard operating systems, such as Windows CE® (Microsoft Corp, One Microsoft Way Redmond, Wash. 98052-6399) and VX Works, can be readily usable with the microcontroller  310 . The microcontroller  310  can also be equipped to communicate with either a computer network  314 , automated devices  330 , and other devices through BlueTooth, RS232, Universal Serial Bus (USB), Ethernet, Wireless, T-carrier connections, Firewire® (Apple Computer, Inc., 1 Infinite Loop, Cupertino, Calif. 95014), Optical fiber, Zigbee® (Philips Electronics North American Corp., Avenue of the Americas New York, N.Y. 100201-104), etc. Examples of interconnection of the RFID base unit  304  with a variety of other devices can be seen with the communication channels  316 ,  318 ,  320 ,  322 ,  324 , and  326 . The RFID base unit  304 , though, does not necessarily need to be connected to a network. Rather than using the network  314  to store information related to authorization, internal memory or other devices storing, accessing or otherwise obtaining the information may be used additionally or as another option. 
   By equipping the RFID base unit  304  to communicate with external devices, there are a variety of configurations. The RFID base unit  304  can be connected to a remote monitoring system or can be monitored over a computer network, such as the Internet. For example, a user can be notified of operation of a through Voice over Internet Protocol (VoIP) on a cell phone. Additionally, several RFID base units  304  could be interconnected or connected with a server. Hence, by having the ability to dynamically interconnect RFID base units  304  with one another and computer networks  314 , the functionality of the RFID base unit  304  and RFID tags  302  can be dynamically changed for changing conditions. For example, RIFD tags  302  can have ID numbers dynamically updated, or the software of the microcontroller  310  can be updated. 
   The RFID base unit  304 , though, has significant potential in controlling the operation of other external devices. For example, the RFID base unit  304  could be coupled to an automated device  330  by a communication channel  328 . Automation equipment  330  can also be connected directly to the I/O module. The RFID base unit  304  can then enable or disable access to the automated device  330 . The RFID base unit  304  can also be coupled to an I/O device  338  through the communication channel  340 , where the RFID base unit  304  can be configured to receive and/or transmit digital and/or relay signals. For example, the RFID base unit  304  can be configured to communicate with Programmable Ladder Logic Controllers (PLCs) that are common in industrial applications or with other I/O modules. 
   The RFID base unit  304  can also be used to discontinue the operation of other external devices. For example, a Power Source Disconnect Module (PSDM) can be used in conjunction with the RFID base unit  304 . The RFID base unit  304  could be helpful as a last line of safety type of device where one might want to turn a piece of equipment completely off if an operator gets too close. For example, an industrial laser can be extremely hazardous and would need to be off if an operator is too close. Additionally, the RFID base unit  304  can be used as a fail safe in case the operator can bypass the other safety devices. Alternatively or additionally, the RFID base unit  304  could be employed to signal a controller if the proper operator is not present and/or in an acceptable location to operate a device, such as a laser or other potentially harmful or otherwise important equipment. 
   In high security situations, additional security devices can be employed in conjunction with the RFID base unit  304 . In  FIG. 3 , an alternative security device  334  can communicate with the RFID base unit  304  through the communication channel  336 . Until conditions of both the RFID tag  302  and the alternative security device  334  are satisfied, access to an automated device or to an area is denied. For example, a fingerprint reader, an iris scanner, a retinal scanner, a facial recognition scanner, and so forth can be used as an alternative security device. 
   Specifically, the RFID base unit  304  is designed to have a great deal of flexibility. There are a large number of combinations of devices, RFID tags, and communication techniques that can be employed to yield that flexibility. Moreover, the RFID base unit  304  is designed to be a lower cost unit so that usage of RFID tags, particularly in commercial and industrial applications, can become more common. 
   An example of the usage of the RFID system  300  in an industrial application is with safety or security. Referring to  FIG. 4  of the drawings, the reference numeral  400  generally designates a flow chart depicting the usage of an RFID system in a safety or security application. 
   In step  410 , an RFID tag interfaces the RFID base unit. The RFID tag can be any type of RFID tag. During the interface, the RFID tag can be energized, and the identification information (ID) is transmitted to the RFID base unit. 
   Once received, the ID is analyzed. A determination is made in step  412  of whether the ID is correct or sufficient to gain access. If the ID is not correct, access to a device or area is denied in step  414 . For example, if an employee attempts to operate a milling machine and if the employee&#39;s ID is not cleared to operate the milling machine, then the mill will not function. 
   If the ID is determined to be sufficient to gain access to a device or area, a further determination is made as to if a second tag is necessary in step  416 . In some industrial and commercial applications, it is necessary to have multiple parties present during the performance of an industrial function. For example the operators of an industrial press: at least two operators need to be present at all times when the equipment is in operation in case someone gets injured such that they cannot get or seek medical attention on their own. The second tag can then be analyzed to determine if the second ID is correct. If the second ID is not correct, then access is again denied in step  414 . 
   Once the RFID tags have proven sufficient to gain access to a device or area, a determination is made in step  420  to determine if a secondary ID is needed. If needed, then a determination is made in step  422  if the secondary ID is correct. If the secondary ID is not correct, then access is again denied in step  414 . However, if the secondary ID is correct, then access is allowed in step  424 . For example, a plasma etching machine may require both an RFID and a thumbprint scan to operate the machine. 
   It is understood that the present invention can take many forms and embodiments. Accordingly, several variations may be made in the foregoing without departing from the spirit or the scope of the invention. The capabilities outlined herein allow for the possibility of a variety of programming models. This disclosure should not be read as preferring any particular programming model, but is instead directed to the underlying mechanisms on which these programming models can be built. 
   Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.