Wireless data input to rfid reader

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DESCRIPTION

Background of the Invention

Field of Invention

[0001] This invention relates generally to the field of radio frequency identification (RFID) systems and devices intended to detect the presence of a transponder tag within a detection field of a reading unit and to read a unique identification code to each such tag to thereby identify a person or object associated with the tag. More particularly this invention is directed to a remote passive programmer for reprogramming microprocessor controlled induction type RFID readers and, more generally, wireless data input to RFID readers or devices associated with RFID readers.

State of the art

[0002] Radio frequency identification systems have become in widespread use in a wide range of applications. One of these applications is the control of access to restricted areas of buildings or plant facilities by authorized personnel, excluding those who lack the necessary authorization. Most such proximity systems consist of a transponder, a reader, and a host computer. The reader generates a radio frequency (usually in the 125 kHz or 13.5 MHz range). The transponder usually consists of an antenna circuit (tuned to the same frequency as the reader's output) and an integrated circuit (IC). Sufficient power is obtained to activate the PC by induction when the transponder is placed within the field of the reader. The frequency of the reader is also used as a clock for the IC. When energized, the transponder IC charges the transponder antenna circuit in a pattern determined by the design and programming of the IC. The transponder antenna load is detected as a pattern of voltage changes in the reader's antenna circuit. The changes are converted into bits of logical data using standard decoding methods and the data is then interpreted by the host computer and the appropriate action is taken (such as opening the door).

[0003] The topology of the different systems can range from a single self-contained door unit containing the reader and host computer in a small box mounted next to a corridor to a complex system consisting of thousands of readers and other input devices / exit connected to a communication network controlled by hundreds of main computers (running specialized software) that control access, movement of people and goods, lighting, heating, ventilation and air conditioning, fuel distribution and other functions. In standalone single door products, and in some systems with distributed intelligence, the reader and the host computer are often combined into a single entity.

[0004] SecuraKey, a division of Soundcraft, Inc., assignee of this invention sells a reader under the name Radio Key ® 600 or RK600, described in their commercial literature as a stand-alone proximity / keypad access control system, which has a programmer Incorporated. This reader is inductive and is designed to work in conjunction with tags, also sold by the same assignee, which are passive bi-directional transponders in which the energy for the tag is derived from the electromagnetic field generated by the reader. Each transponder consists of an integrated circuit and an antenna coil, both embedded in a small plastic tag or token. The transponder tag integrated circuit is a TEMIC e5550 Contactless Identification IC - R / W (IDIC ®) device sold by the semiconductor division of Temic Telefunken microelectronic GmbH, POB 3535, D-74025 Heilbronn, Germany.

[0005] There is a need for periodic reprogramming of such proximity systems as authorized personnel and access control requirements change. For example, when transponder tags are issued to newly authorized persons, the new tags must be entered into the reader's programmed database to be recognized when presented to the reader. Likewise, tags must be removed from the database when staff leave the company or are reassigned. In large RFID systems such reprogramming is normally done through the main computer linked to multiple readers. In smaller systems or those lacking centralized control, it may be necessary to reprogram each reader. Conventionally, this can be achieved via a keyboard provided in the reader unit itself, as in the aforementioned RK600 reader. It is often desirable to provide means for remote programming of the reader for convenience or security reasons. Radio frequency linked remote handheld programmers are available for this purpose. These types of units usually include a keyboard connected to a microprocessor that delivers programming data transmitted through a low-power radio frequency carrier generated by the programming unit. Passive programmers are also available that derive their operating power from the electromagnetic field emitted by the reader. Existing passive programmers, however, are based on a microprocessor and are of considerable complexity. Also, the power requirements of these existing units are relatively large, resulting in a fairly short operating range because the controller must be placed close enough to the reader where the field strength is sufficient to power the controller. There is a continuing need for simpler and lower cost passive programmers, especially for use with small or standalone RFID installations.

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[0006] More recently, RFID transponder tags have become available, which are individually addressable by the RFID reader. That is, the tag does not automatically respond with its tag code when it is in the induction field of the RFID reader until it is specifically requested or interrogated by the reader with the unique tag identification code of that tag. This allows the reading of several tags simultaneously present in the RF induction field of the reader. Examples of such tags are the I_CODE series of RFID tags sold by Philips Electronics, and the M35101 contactless memory chip, sold by ST. Suitable RFID readers capable of reading multiple transponders simultaneously present in their induction field include the ET-WS and ET-RS proximity high-frequency readers sold by Secura Key, a division of Soundcraft Inc .. The RFID reader is pre-programmed with the unique identification code of each tag in the group of tags or population to be read and the reader performs an analysis or a reading sequence in which it transmits sequentially, by modulation of its induction field, The unique pre-programmed tag identification codes. The reader cyclically analyzes or sequences this read at a relatively high repetition rate sufficient to reasonably ensure that the presence of any of the tags in the reader's detection field does not go unnoticed.

[0007] WO 00/036849 discloses a passive remote handheld programmer for a microprocessor-controlled induction type RFID reader, the programmer having a keyboard with a plurality of keys, each selectively operable to connect a corresponding one of a plurality of tags transponder to an antenna to thereby energize the IC of the selected tag by induction in the radio frequency detection field of the RFID reader.

Summary of the Invention

[0008] According to the invention, there is provided a method according to claim 1, an RFID system according to claim 3, and a passive wireless remote keypad according to claim 5.

[0009] This invention addresses the aforementioned need by providing a simpler passive remote programmer for induction type RFID readers. The new remote programmer is economical in design, requiring only three main components: a keyboard, an antenna, and a series of low-cost, commercially available transponder tags. Each of the transponder tags, when connected to the antenna by pressing a key on the keyboard, communicates with the RFID reader by discharging the magnetic field in the vicinity of the reader's transmitting antenna in a pattern that the reader interprets. and decode as digital data.

More specifically, the passive remote programming system of this invention is devised for use with an induction type RFID reader with radio frequency (RF) sensing means operatively connected to a digital processor, such as a microprocessor, for reading tag identification data from transponder RFID tags powered by a sensing field of the reader and for verifying identification data with stored identification data to thereby recognize the presence of authorized tags.

The programmer that can be a portable unit houses an antenna, such as a loop antenna, a series of specific RFID transponder tags each with a unique tag code, and a keypad having a plurality of keys each selectively operable to connect a corresponding one of the specific transponder RFID tags to the antenna to induction energize the selected tag in the reader's sensing field and allow the unique tag code of the selected tag is read by said RFID reader. The remote programmer works in conjunction with the reader's microprocessor programming to recognize the unique tag codes of specific tags as new reader programming instructions. In most cases, the reader program is also operative to preserve or store the new program instructions in the memory of the microprocessor for later execution by the microprocessor. New program instructions may, for example, contain data to modify a transponder tag database accessible to the reader's microprocessor for use in executing decision-making algorithms such as granting or denying access after reading a code. label in particular.

[0012] The RFID reader can respond to the recognition of the aforementioned keystroke by executing preprogrammed instructions of any appropriate type, such as generating ASCII characters to simulate keyboard data entry, for example, whose data entry It may be communicated to other devices or systems, such as a computer system, by the RFID reader for further processing.

These and other features, improvements and advantages of the present invention will be better appreciated and understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

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Brief Description of Drawings

[0014]

Fig. 1 is a perspective view illustrating a normal RFID reader equipment equipped with a keyboard and a remote programmer packaged as a portable unit, as described in WO 00/036849;

Fig. 2 is a circuit diagram of a remote programmer, as described in WO 00/036849;

Fig. 3 is a circuit diagram of a wireless data entry system in accordance with this invention, and

Fig. 4 is a table showing exemplary tag permutations in a data entry unit, such as a keyboard or panel with seven toggle keys and three individually addressable transponder RFID tags.

Detailed Description of Preferred Embodiments

With reference to the accompanying drawings, in which like elements are designated by like numerals, Fig. 1 shows a typical proximity RFID reader unit 10 contained in a reader housing 12 that is mounted on a wall 14. For purposes of this description the reader 10 may be an RK600 sold by SecuraKey equipped with an externally mounted keyboard 16, which provides an interface to access the reader's microprocessor control system. In most installations, such access requires entering an authorized password before the keyboard is enabled for reprogramming the reader unit. The keypad can also be used to enter a personal identification number (PIN) as an alternative to presenting a label.

[0016] A remote passive programmer 18 in accordance with this invention is shown having a housing 20 in which a keyboard 22 is mounted. The housing 20 may be a small box sized for convenient portable operation. The remote programmer's keyboard may be a duplicate of the reader's keyboard 16, or it may be configured differently.

Let us now turn to Figure 2, which shows a circuit diagram of the remote passive programmer 18. It will be appreciated that this circuit is quite simple and with few components. Switches S1 through S16 are normally open switches corresponding to sixteen keys arranged in a four-by-four matrix on keyboard 22. Integrated circuits IC1 through IC16 are sixteen similar transponder tags programmed to transmit a unique identification code when triggered by the inductive sensing field of a proximity reader. The transponder ICs can be TEMIC e5550 devices that work with the RK600 reader. The antenna coil L1 and the capacitor C1 form an antenna tank circuit that is resonant at the frequency of the proximity reader transmitter. For example, L1 can be a 1.62 mH coil and C1 can have a value of 1,000 pF. Each tag IC has two active terminals, one of which is connected directly to one side of the antenna tank circuit via bus line 24. The other active terminal of each tag IC is connected via a corresponding switch normally open S1-S16 on the other side of the antenna tank circuit through bus line 26. In a normal programmer situation all switches S1-S16 are open and none of IC1-IC16 is connected to the antenna circuit. Consequently, if the remote programmer unit 18 is placed in this situation within the detection field of the reader unit 10, the programming unit will not respond to the detection field of the reader. If, however, any of the keyboard keys is pressed, closing one of the S1-S16 switches, the corresponding one of IC1-IC16 will have its two active terminals operatively connected through the antenna tank circuit. In this situation, the operating IC will be powered by inductively coupled power from the reader to the antenna coil L1, and will transmit its unique tag code to the reader. The transponder IC can be in the form of a chip attached to the surface and the entire circuit of Figure 2 can be easily implemented on a single circuit board that can also carry the keyboard and antenna coil. The resulting package is light and strong. The passive programmer described in this document presents improvements over previous passive programmers, not only in terms of greater simplicity and economy, but also in extended range of operation from the proximity reader since transponder tags have lower power requirements than a microprocessor-based passive programmer.

[0018] The program executed by the reader's microprocessor is written to recognize the unique tag codes of the programmer's transponder tag IC1-IC16 of a different function than ordinary access tag data. In particular, the reader's program must recognize the reading of the specific tag codes as representing the actuation of a key rather than the presentation of a conventional tag to the proximity reader. This recognition can be used by the reader's programmer for any desired purpose. For example, the keys corresponding to the digits 0 through 9 may each be represented by a particular and unique tag code, so that numerical data can be entered into the reader by pressing a sequence of keys. Similarly, logical function keys such as ADD or DELETE may be represented by corresponding single label codes. They can still be assigned to other control functions, such as an ENTER key on the keyboard, tag codes

ES 2 395 075 T3 corresponding. For example, the remote programmer can be used to add or remove authorized tags at the base of the data reader, by pressing a sequence of digits and then pressing an ENTER key or to enter PIN codes at the reader as an alternative to using the keyboard. 16 in reader unit 10. In fact, the remote programmer can completely replace the reader's keyboard without sacrificing the reader's programmability, resulting in a more secure installation since the keyboard is no longer accessible on the reader. In addition, the elimination of the keyboard makes it possible to better seal the box or reader housing for better resistance to atmospheric conditions, time trials and environmental contaminants.

[0019] The way to program the reader's microprocessor to carry out this recognition will be obvious to those with ordinary knowledge of these systems and need not be described in more detail here, especially in view of the many ways in which the systems The proximity reader can be programmed for both conventional and application purposes of the present invention. The programming that controls the operation of the reader's microprocessor can be installed as firmware in non-volatile memory provided on the processor chip. Of course, other program storage devices can be provided for this purpose. For the purposes of this invention, the reader control program must contain information that allows the reader to identify the unique identification code transmitted by the transponder tags in the remote programmer so that they are distinguishable from other non-actuated transponder tags. a key or switch, like conventional labels. This information is different from the database that the microprocessor accesses in order to identify conventional labels authorized for access. Recognition of keypad-enabled transponder tags allows programming of the reader to perform a special action in response to those tags, different from action taken in response to conventional tags that are activated simply by sufficient proximity to the reader.

[0020] The number and functions of keyboard keys that can be wirelessly encoded and linked to a reader in this way is virtually unlimited. As a practical matter, however, this approach to passive remote programming may be found to be more suitable for smaller keyboards, while programming units that require large and complex keyboards are better implemented with microprocessor-controlled circuitry.

[0021] It should be understood that this invention is not limited to proximity systems of any particular manufacturer, and is generally useful with any induction type proximity reader provided that the tag ICs used in the remote programming unit can be read by the target proximity reader.

[0022] The wireless data entry system described above works well when the number of keys or switches is relatively small. As the number of keys required in a particular application grows, so does the number of transponder labels. At some point, it becomes easier to build a specific standard electronic circuit for that application. This limitation is addressed by the wireless data input of Figs 3 and 4, as explained below.

Figures 3 and 4 of the drawings represent a system and method for wireless data entry to an RFID reader. The system shown has seven switch keys designated S1 through S7 in the drawings, and three individually addressable RFID transponder tags A, B, and C. As shown in Figure 3, each of the seven S1-S7 switches is connected to one or more of a group of three individually addressable RFID transponder tags A, B, and C, and also to an antenna that in the illustrated example It consists of coil L1 and capacitor C1 connected to form a circuit tuned to the frequency of the radio frequency induction field of the RFID reader. The connections in the circuit of Figure 3 are such that they apply the logic table of Figure 4. That is, the actuation of the switch S1 electrically connects the individually addressable transponder C to the antenna circuit L1-C1, which enables the transponder C which can then be activated when it is individually addressed or interrogated by the RFID reader. However, activating switch S1 does not enable transponders A and B which cannot be addressed by the RFID reader. Activating switch S6, on the other hand, enables transponders A and B, but not transponder C. With switch S6 closed, both transponders A and B are able to receive the interrogation signal from the RFID reader transmitted sequentially during the RFID reader read cycle, and can respond to such interrogation by returning the unique tag identification codes of each transponder. . The RFID reader, upon receiving the unique codes from the transponders of A and B, is able to interpret that this combination of tag codes represents the activation of the switch S5 through the appropriate pre-programming of the reader's microprocessor. As shown in the table of Figure 4 each switch S1-S7 has a corresponding permutation of transponders A, B, C, resulting in a unique combination of tag codes associated with each of the switches.

[0024] It can be appreciated that seven switch key data entry is possible in this example using only three individually addressable RFID transponder tags. That is, there is no longer a one-to-one correspondence between each switch and a corresponding label. Rather, each switch is associated with a unique set of one or more transponder labels, so different permutations of a smaller group of labels can be assigned to each of the switches. Switches S1-S7 can be on

ES 2 395 075 T3 form of keyboard 22 mounted in a portable housing 20, as shown in Figure 1, with the AC transponder labels contained in the housing on a suitable printed circuit.

[0025] Expanding on the example of Figures 3 and 4, a full QWERTY type 5 computer keyboard can be constructed that does not have any built-in power supply and would require 8-10 transponder tags, one or more antenna coils (depending on charging considerations) and a keyboard that connects the appropriate transponders via a circuit board for each key.

[0026] While particular embodiments of the invention have been described and illustrated for purposes of clarity and example, many changes, substitutions, and modifications to the disclosed embodiments will be apparent to those of ordinary skill in this technology, without thereby departing from the scope of the invention. this invention as defined in the claims.