Abstract:
An intelligent asset protection system is claimed and disclosed which features a plurality of devices are used to protect a retail establishment by radiating and detecting into a protection zone to identify transponders within a given area. These devices that radiate and detect are typically located in the ceiling or above the area that is desired to be monitored and create a cone shaped interrogation field which expands as it is broadcast downward into the monitored area. In communication with the RAD units, the system uses transponders capable of storing information which includes passwords and unique identifiers as well as information about the object to which the transponder is attached. The transponder is capable of responding to a RAD unit and broadcasting information to it which may include the information stored on the transponder. The transponder in some embodiments will have a battery located on board, but the transponder will remain in an inactive sleep mode until a RAD unit contacts it with a radiated

Description:
RELATED U.S. APPLICATION DATA 
       [0001]    This application claims priority from U.S. provisional application No. 61/030,929, filed on Feb. 22, 2008, and U.S. provisional application No. 61/030,932 filed on Feb. 22, 2008. The entire disclosure contained in U.S. provisional application 61/030,929 and U.S. provisional application No. 61/030,932, including the attachments thereto are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    A common logistical concern in businesses is the tracking of assets or persons. In retail, one example of this logistical tracking concern is shoplifting. Many retail establishments employ electronic tags attached to goods that can be detected by systems installed for that purpose. A common term for these systems, tags, etc. is electronic article surveillance, or EAS. 
         [0003]    Many of these tags and systems are only capable of registering the presence of the tag. Transmitters and receivers are located at exit points within a retail environment and the transmitter creates an interrogation zone at the exits while the receivers scan for responses from tags passing through the interrogation zone. There are several types of tags for these systems, one of which is a harmonic tag and another of which is a resonance tag. With the harmonic tag the electromagnetic interrogation field charges the circuitry of the harmonic tag, and when the interrogation field is turned off this energy dissipates from the tag and produces a signal which is a harmonic of the interrogation field. With the resonant tags, the resonant tags vibrate with the interrogation field and produce a signal from this harmonic resonant. The system is tuned to the expected frequencies whether they are harmonic tags or resonant tags, and the receiver antennas of the system detect these signals. When a signal is detected by an interrogation field, it is assumed that a tag is present and that it is improperly being removed from the retail facility. Similar systems may also be used to identify authorized personnel. In these cases, the tags might be identification badges, and the badges are only capable of indicating that an authorized person is present, for example, at an access door. 
         [0004]    With the improvement of electronic circuitry and miniaturization, tags capable of doing more than just announce their presence are being developed. Theses tags may have onboard power supplies to allow them to power programmable circuits that transmit information in digital form. This information may be as simple as a unique identifier of the tag, or the transmission from the tag might include information about the object to which the tag is attached. This information is programmed into a tag at the time the tag is attached to an object. Many of these systems also use a transmitting antenna to prod the tags into responding. Various schemes are used to prevent more than one tag from responding at the same time. This prevents the tags from interfering with each other&#39;s signals. Other systems employ a scheme where tags pseudo randomly chirp out their identifier, so that the receiver of a system may note their presence and in many cases calculate their physical location by the signal. 
         [0005]    Similar to the tag system above, personnel monitoring systems utilize identification tags which respond when queried. Again, these tags would most typically only broadcast when prodded by a system signal. This allows the batter on such a tag to last longer and prevents interference from random signals from multiple tags. 
       RELEVANT ART 
       [0006]    U.S. Pat. No. 6,483,427 by Werb discloses an article tracking system. The article tracking system uses cell controllers with multiple antenna modules to monitor the desired space. Each cell controller alternately operates various multiple antennas to create interrogation zones by each antenna. The antennas can prompt transponders within their areas to respond with the signal and receive information from the transponders. This information is processed by the cell controllers and transmitted back to a central computer. The cell controllers can be powered by typical wall outlets. The use of multiple antennas allows a transponder to be in constant range of the system and the system can also track the movement or relocation of a transponder as different antennas detect and transmit the information back through the cell controllers to a central computer. The information function of the system and its power requirements are provided separately. 
         [0007]    U.S. Pat. No. 6,570,487 by Steeves discloses and claims a distributed tag reader system and method. Steeves employs independent tag readers and door controls at entries and exits to controlled areas. Each tag detector and door control is able to operate independently and when a tag is detected, it to evaluate whether the bearer of that tag is entitled to entry. A central application program interface provides for programming and database access to set appropriate access levels for given tags. The independent detection and control devices are networked together to the central application programming interface. The networked access modules are capable of receiving information from other modules and transmitting those through the network to the central computer. 
         [0008]    U.S. Pat. No. 7,176,797, by Zai, et al. discloses an electronic article surveillance (EAS) system that uses a large zone electronic article detector with several smaller zone electronic article detectors operating within the larger zone. Each of the smaller zone detectors does not overlap with any of the other smaller zone detectors, and each of the smaller zone detectors operates on a different frequency from neighboring small zone detectors. If an EAS tag or transponder is not detectable by a smaller zone detector, it is detected by the larger zone detector. The system associates the tag with the detector that has located the tag or transponder. The tags themselves can operate at the different frequencies in which the several electronic article detectors operate. The electronic article detectors can operate at several different frequencies, but they are arranged and programmed so that their frequencies are different from immediate neighbors. 
       SUMMARY OF THE INVENTION 
       [0009]    A plurality of devices are used to radiate and detect transponders within a given area. These devices that radiate and detect are referred to as radiation and detection units or RADs or RAD units. The RAD units are typically located in the ceiling or above the area that is desired to be monitored. They create a cone shaped interrogation field which expands as it is broadcast downward into the monitored area. The RAD units can be located densely enough to thoroughly cover the floor level area being monitored. 
         [0010]    In conjunction with the RAD units, the system uses transponders which are attached to the objects being monitored. The transponders are capable of storing information which includes passwords and unique identifiers for each transponder, as well as information about the object to which the transponder is attached. The transponder is capable of responding to a RAD unit and broadcasting information to it which may include the information stored on the transponder. The transponder in some embodiments will have a battery located on board, but the transponder will remain in an inactive sleep mode until a RAD unit contacts it with a radiated signal. At that time, the transponder awakens, recognizes the RAD unit, and transmits information as requested by the RAD unit, and the RAD unit detects the signal from the transponder. If the transponder has been associated within the system with an article, this unique transponder identifier will serve to identify that article. 
         [0011]    In addition to surveying the quantity of transponders present in its area and determining which transponders are there, one embodiment of the system can determine the physical location of a transponder. There are several algorithms which may be used to accomplish this by using the time it takes the transponder to respond to the RAD unit. Some algorithms can utilize the interaction of a given transponder with more than one RAD unit to more accurately determine the location of the transponder. 
         [0012]    In addition to storing and communicating information, the transponder can provide a security function, RAD units positioned near security exits, such as store exits in retail situations, can instruct the transponder to emit an alarm signal. This alarm signal can be instructed to continue until instructed otherwise or until the battery is discharged. The transponder alarm signal can also be triggered by an unauthorized attempt to forcibly remove the transponder from an object. Again, in the case where a transponder is alarming, because an attempt has been made to forcibly remove it, the transponder can alarm until the battery is discharged or until a RAD unit instructs it to cease alarming. In one embodiment, the transponder will require confirmation of its password before executing certain instructions from a RAD; instructions such as to cease self alarm, etc. 
         [0013]    Each RAD unit is connected to a server via cables and a switch. The cables, or wires, connecting each RAD unit to the switch are capable of both transmitting data and conducting power for the RAD unit. Data transmission via the cables is bidirectional and the information transmitted can be instructions and programming traveling from the server to individual RADs and transponders as well as information traveling from transponders and RADs to the server. The switch supplies power to the cables for the RAD units. From the switch, information is conducted to the server, and the switch can also perform data traffic control in some embodiments. A common type of switch used for this purpose is a Power over Ethernet (PoE) switch. 
         [0014]    The server performs both database and control functions. Software on the server allows a user to set instructions for each individual RAD unit and how that RAD unit communicates with the transponders. It is also possible to reprogram information on transponders via the RAD unit that is closest to the transponder. The server software allows RAD units located near entries and exits to operate differently from RAD units out in an area of general inventory. The server database may track the location of the inventory and changes in that inventory. Along with transponders placed in inventory, the server and RAD units may interact with personnel ID badges to monitor personnel activity, in particular, with regard to high value inventory, or in other applications to provide access control. 
         [0015]    Transponders may come in a large variety of embodiments. This large variety results from several factors including whether the transponders will be interacting with multiple systems, the types of system, and the level of functionality desired by a user of the systems and transponders. For example if transponders will be operating in an environment where an EAS system is deployed for detecting passive tags, the transponders may have EAS sensors such as EAS ferrites or EAS resonators. Various embodiments of the transponder may have a microprocessor, digital controllers, memory, internal antennas, an audible alarm generator, attachment mechanisms, tamper detection means, light emitting diodes for visible alarms, clock, supplemental communication means such as infrared capabilities, batteries, etc. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Additional utility and features of the invention will become more fully apparent to those skilled in the art by reference to the following drawings, which illustrate the primary features of the preferred embodiment. 
           [0017]      FIG. 1  is a perspective view of an asset protection system according to one embodiment of the invention. 
           [0018]      FIG. 2  provides a closer view of some of the elements of the system in the embodiment shown in  FIG. 1 . 
           [0019]      FIG. 3  shows a view of an embodiment of a RAD unit. 
           [0020]      FIG. 4  shows several embodiments of transponders  30 . 
           [0021]      FIG. 5  is a top perspective view of tack attached tag compatible with the intelligent asset protection system of one embodiment. 
           [0022]      FIG. 6  is a bottom perspective view of the tack attached tag of  FIG. 5 . 
           [0023]      FIG. 7  is an exploded perspective view of the tack attached tag of  FIGS. 5 and 6 . 
           [0024]      FIG. 8  is a perspective view of a lanyard tag compatible with the intelligent asset protection system of one embodiment. 
           [0025]      FIG. 9  is a top view of the lanyard tag of  FIG. 7 . 
           [0026]      FIG. 10  is a bottom view of the lanyard tag of  FIG. 7 . 
           [0027]      FIG. 11  is a perspective view of the lanyard tag of  FIG. 8  with the outer shell made transparent. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0028]    The detailed description below is for embodiments intended to illustrate and explain the current invention. It is to be understood that a variety of other arrangements are also possible without departing from the spirit and scope of the invention. Where appropriate, the same numbering will be used when discussing different embodiments. 
         [0029]      FIG. 1  is a schematic view of the asset protection system  10 . A plurality of radiation and detection units (RAD units)  20  are used by the asset protection system  10  to monitor an area. In one embodiment, each RAD  20  has at least a programmable controller, memory, signal transmitting and receiving means, and a cable receptacle for receiving a cable for transmitting power and data. Each RAD unit  20  is independently capable of radiating an area and also scanning for reply signals. In one embodiment the RAD units  20  are mounted overhead. This allows the entire target area to be monitored without intrusive installations at the level where persons and objects will be located. RAD units  20  operate to detect transponders  30  as shown in  FIG. 1 . 
         [0030]    Transponders  30  are capable of detecting a signal from RAD units  20  and responding. IN at least one embodiment, communications between RAD units  20  and transponders  30  is in the radio frequency range of 400 MHz to 1 GHz, but other frequency ranges can be used. Transponders  30  have information storage means located within them which can store various types of information such as a unique identifying number associated with that transponder, a security, information about the object to which the transponder is attached, tag history etc. In some embodiments, a unique security password can be assigned to each tag with the system storing the password associated with each transponder  30  in a table. Other embodiments may use a system wide password that can be changed periodically. The exchange of information between RAD units  20  and transponders  30  allow the asset protection system  10  to monitor the location of assets associated with the transponders. The ability of transponders  30  to store information about the asset to which they are attached and to transmit that information, allows detailed awareness of assets, and if a transponder  30  is associated with a person, awareness of that person&#39;s location as well. Also, in some embodiments, transponder  30  has onboard audible alarm capabilities. The alarm on transponder  30  can be instructed to sound by a RAD unit  20  if it is determined by the system  10  that the object to which transponder  30  is attached is being inappropriately moved, or if an unauthorized attempt is made to forcibly remove transponder  30  from an object to which it is attached. Transponder  30  may sound the alarm until instructed otherwise by system  10  or until its power is depleted. In one embodiment, a transponder has several elements including; a digital controller, memory, antenna, battery, audible alarm, locking device. Some embodiments of transponder  30  may also have a resonator or ferrite compatible with electronic article surveillance systems. In these other types of EAS systems, passive elements such as ferrites and resonators are detected by security antennas set up at exits or other restricted areas. 
         [0031]    Each RAD unit  20  has a communication connection back to a central server  40 . This connection is accomplished by cables  50  and a switch  60 . In one embodiment the switch  60  is a Power over Ethernet (POE) switch which allows both information and power to be conducted over cables  50  connecting RAD units  20  to switch  60 . In at least one embodiment, switch  60  provides information traffic control between the plurality of RAD units  20  and server  40 . Server  40  is capable of running an off-the-shelf operating system and the software controls of the asset protection system  10  run in this server operating system. A user can establish all the rules for asset protection system and database management through a graphical user interface. The software of the asset protection system  10  provides flexibility in giving different instructions and settings to individual RAD units  20 . For example, a RAD unit  20  which is located near an exit  70  of a monitored area could be instructed by settings in the software of server  40  to radiate and detect in the area near the exit  70  at a much more frequent rate than a RAD unit  20  which is in an area for inventory purposes only. The software of server  40  could also be set to instruct a RAD unit  20  at an exit  70  to set a transponder  30  to alarm continuously if it appears that the transponder, and therefore the asset it is attached to, is being removed from the monitored area. The transponder  30  would alarm until instructed otherwise by RAD unit  20 , or until the onboard power source of the transponder  30  is depleted. In one embodiment, transponder  30  requires confirmation of its password from RAD unit  20  before ceasing to alarm. 
         [0032]    The software of server  40  provides other capabilities. One embodiment uses the plurality of RAD units  20  to periodically inventory a monitored area. Another embodiment uses the RAD units to determine specific locations of transponders. In these embodiments the software of server  40  is capable of analyzing the timing of signals between RAD units  20  and transponders  30  to calculate the distance of a transponder  30  from a given RAD unit  20 . For increased accuracy multiple RAD units  20  within range of the same transponder  30  can be used to triangulate a highly accurate position for that transponder  30 . The radiating field of RAD units  20  can be shaped to prevent excessive overlap, or interference, between the fields of RAD units  20 . In one embodiment these fields are generally conical shaped, expanding as the field extends away from a given RAD unit  20 . This provides a larger area of coverage down at the level where activity typically occurs. In another embodiment the asset protection system  10  provides access control. This is accomplished by transponders  30  being associated with persons, and the transponders  30  contain information identifying the person who is wearing the transponder  30 . The asset protection system  10  is able to identify the location of a particular person at an access control point, such as a security door, and then allows or denies the entry of the person by either unlocking the door, or by maintaining the door in a locked status. 
         [0033]      FIG. 2  shows, in more detail, components of the asset protection system  10 . In particular,  FIG. 2  shows the multiple ports in switch  60 . These multiple ports allow the connection of a plurality of RAD units to the switch  60 , and switch  60  controls data traffic between the RAD units and the server  40 . Server  40  receives data from the plurality of RAD units  20  as well as sends instructions to the RAD units  20 . Switch  60  also provides power to RAD units  20  over cables  50 , in some embodiments. 
         [0034]      FIG. 3  shows a view of an embodiment of a RAD unit labeled in other figures as  20 . RAD units  20  perform all interrogation and collection of data relative to the area to which they are assigned. RAD units can be installed above the area of interest to monitor that area. The RAD units  20  radiate their particular area and listen for any responses from transponders  30 . Once a transponder is detected, or responds, the RAD unit  20  takes further action as dictated by the server software. The RAD units  20  communicate and receive instructions, settings, reprogramming, etc. from the server via large area network space (LAN) connections or cables. Each RAD unit  20  is connected back to the server  40  via the cables  50  and switch  60  as previously discussed in reference to  FIG. 1 . 
         [0035]    The radiated field of RAD unit  20  can be tuned to form a cone pattern. The field generated by a particular RAD addresses transponders  30  within its area, and these transponders are awoken and respond with information. The interrogation cycle of RAD units  20  is set by the server  40 . RAD units can be programmed to a range of settings from only occasionally radiating to nearly continuous radiating depending on the location of the RAD unit and the rules programmed by the user. 
         [0036]    Depending on where a RAD unit  20  is positioned in a facility the server software can periodically interrogate each area to perform inventory checks of assets and/or people to determine presence, absence or movement, authorized or unauthorized. As discussed above, by placing a RAD unit  20  at point of egress, exit  70  location security is assured by continuously pulsing the location, and listening for a response. As the asset/person enters the radiated area, the RAD unit  20  will recognize the transponder and then enable the transponder alarm, which will continue to alarm until it is disarmed by the RAD unit  20  or the battery finally discharges. Access control can also be facilitated by transponders included with employee badges, controlling movements of assets and/or employees. 
         [0037]    Referring now to  FIG. 4 , several embodiments of transponder  30  are shown. Transponders can take the form of tags, lanyards, badges, badge holders, etc. There is no reasonable limit to the transponder shape or application it can serve. Each transponder stores information specified by the server, including transponder ID, security password, and information relative to the asset or individual to which the transponder is attached. If the transponder&#39;s unique identifier (UID) or stored information needs modification, the application software can do this by uniquely addressing the transponder and then modifying its contents. Transponders also have alarming capability which can be turned on/off by the server. Transponder tampering will also cause it to alarm. In one mode of operation, each transponder is normally in a sleep mode to extend battery life and is awakened by RAD unit  20  for interaction. 
         [0038]    Depending on the embodiment, each transponder may include a digital controller, memory, antenna, battery audible alarm, attaching mechanism and, optionally, a resonator, ferrite. The transponder is pre-coded at the time of manufacture with a readable UID. This will allow the server to uniquely access the transponder via the RAD units and make any necessary code changes. Each transponder will self-alarm if its locking mechanism is compromised or it is removed from the premises without first being disarmed. By placing a RAD unit  20  at an exit  70  location the alarm can be commanded by the RAD. 
         [0039]    Returning now to server  40  of  FIG. 1 , the server software can define all the RAD unit controls, follow on actions, and data base management. The menu driven software allows the user to define each transponder and establish rules regarding its location and movement. 
         [0040]    RAD units  20  at the points of exit  70  may be programmed to continuously radiate the area, awakening any approaching transponders. At this point, the RAD unit  20  can cause the transponder  30  to emit an audible alarm plus inform the server  40  of the detection at which time the server  40  can alert others via contact closure or electronic message. 
         [0041]    In one embodiment, RAD units  20  may also be kept in a quiet mode and only radiate when directed. This function would be useful where certain valuables are placed in an area. As programmed by the user, the RAD unit  20  will periodically radiate the area and collect information relative to protected valuables, basically taking inventory of those assets. Employees may also be badged to ascertain their movement in much the same way as other assets. For example, if an employee attempts to remove a tagged item from the premises, not only will the items transponder be detected, but the employee&#39;s badge as well, immediately linking that employee with that item. 
         [0042]    Referring to  FIG. 1 , the modular aspects of RAD units  20  allow them to be placed according to a users unique requirements as dictated by the facility within which the assets protection system  10  is installed, and according to the particular use intended for the system. As indicated in  FIG. 4 , transponders  30 , used for any given asset protection system  10 , can be specifically matched for the needs of the application. Transponders  30  may take the form of lanyard tags, personnel badges. etc. The connection of the RAD units  20  to the server is accomplished by individual cables  50  which further allows the asset monitoring system  10  to be tailored to the specific applications. The modular structure of the physical components of the asset protection system, as well as the modular component capabilities of the server software, allows the asset protection system  10  to serve an unlimited number of applications. The software of the asset protection system  10  can be interacted with via a graphical user interface for ease of interaction by a user. 
         [0043]      FIGS. 5 and 6  show external perspective views of an embodiment of a tack retained tag  300 . Tack  301  has a shaft  302  and head  303 . To retain tag  300  on an article, tack shaft  302  is passed through the article and into aperture  304 , shown in  FIG. 5 , where tack  301  is releasably retained by a mechanism located in tag  300 . In one embodiment of tag  300 , the mechanism that retains tack shaft  302  in aperture  304  is a ball clutch which can be made to release tack shall  302  by application of a strong magnetic force to clutch cone  305 . Another type of mechanism uses sliding wedges  306 , visible in  FIG. 7 , to retain tack shaft  302 . This embodiment can also be made to release tack shaft  302  by application of a strong magnetic force to clutch cone  305 . In some embodiments clutch housing  307 , visible in  FIG. 7 , has at least some magnetically attractable material in it, and is the element acted upon by the strong magnetic force to release the tack shaft  302 . 
         [0044]    Depending on the specific embodiment, tag, or transponder  300 , may have several more features or elements in addition to those already discussed. Visible in  FIG. 5  are possible elements switch button  308  and a first, top infrared communication port  309 . Visible in  FIG. 7  are additional possible elements including; a light emitting diode (LED)  310 , battery  311 , circuit board  312  with microprocessor clock, and communication antenna components (microprocessor, clock, and communication antenna components are not visible in  FIG. 7 ), audible alarm generator  313 , and EAS ferrite  314 . While the embodiment of tag  300  shown in  FIG. 7  has an EAS ferrite  365 , other embodiments might use a resonator, which is a common detectable element used in EAS tags. Another possible element that may accompany audible alarm generator  313 , is sound vent  315 , most visible in  FIGS. 6 and 7 . Sound vent  315  allows the alarm to be more audible by allowing a path for sound to leave tag  300 . 
         [0045]    Tag  300  is capable of self alarming upon the occurrence of any one of several events. One event that can trigger self alarming by tag  300  is physical tampering with the tag. If tack  301  is forcibly removed or if tack head  303  is pried off of tack shaft  302 , tag  300  will alarm with audible alarm generator  313  generating an audible sound. Switch button  308 , visible in  FIG. 5 , is depressed by tack head  303  when tack  301  is inserted into tag  300 . If tack  301  is forcibly removed or if tack head  303  is pried off of tack shaft  302 , switch button  306  is released from its depressed position causing tag  300  to self alarm and also notify the system that a tag has been tampered with via the RAD unit closest to the damaged tag. Tag  300  communicates with RAD units  20  with communication antenna components located on circuit board  3   12  and can also be instructed to cease alarming by the system via the RAD units. Some embodiments of tag  300  will self alarm when the body of tag  300  is opened or otherwise compromised. In this case the self alarm may be triggered by the displacement of circuit board  312  or other means. 
         [0046]    Another event that can trigger an alarm by the audible alarm generator  313  on board tag  300  is instruction to do so by a RAD unit. This can occur when a RAD unit generates a response from tag  300  and the RAD unit is programmed to instruct tag  300  to self alarm because that RAD unit is monitoring a sensitive area such as an exit and therefore tag  300  is in a sensitive area. For example, referring to  FIG. 1 , the RAD units  20  located near exit  70  can be programmed distinctly from RAD units not located as close to exit  70 . RAD units  20  located near exit  70  can be programmed to instruct tags  300  in communication with those RAD units to self alarm. 
         [0047]    A further event that may cause some embodiments of tag  300  to self alarm is interaction with more basic electronic article surveillance systems through ferrite  314 , or a resonator, in some embodiments. EAS systems generate interrogation fields, usually near exits. These interrogation fields are electromagnetic fields in the radio frequency range of electromagnetic waves typically in the 58 kHz area. While the interrogation field is being generated, it develops stored energy in a ferrite, or resonator,  314  in tag  300 . When the interrogation field is no longer being generated and the EAS system switches to monitoring for a signal, the energy stored in ferrite  314 , dissipates and generates a signal in the process. This signal is detected by the monitoring EAS system. Detection of tag  300  by an article surveillance system will cause the article surveillance system to generate a system alarm, audible or otherwise. However, the activity in ferrite  314  is also detectable by circuit board  312  which can trigger a self alarm by tag  300 . 
         [0048]    All in all, there are several ways that various embodiments of tag  300  can generate alarms. Tag  300  can self alarm with its onboard audible alarm generator  313  when tampered with. Tag  300  can self alarm with its onboard audible alarm generator  313  when instructed to by a RAD unit. Tag  300  can self alarm with its onboard audible alarm generator  313  when it detects that an onboard electronic article surveillance element such as ferrite  314 , or a resonator, is being stimulated by an electronic article surveillance interrogation zone. An article surveillance system can also generate a system alarm when it detects the presence of a tag  300  having an electronic article surveillance ferrite, or resonator,  314 . In some cases, RAD unit  20  can instruct tag  300  to cease to self alarm. At least one embodiment of tag  300  requires confirmation of its password before executing instruction from a RAD unit. 
         [0049]      FIG. 8  shows an external perspective view of an embodiment of a lanyard retained tag, or transponder  350 , while  FIGS. 9 and 10  show top and bottom views of lanyard tag  350 , respectively, and  FIG. 11  shows internal components of lanyard tag  350 . Lanyard  351  has a permanently anchored end  352  and a coupler end  353 , and, in some embodiments, along its length, some portion of lanyard  351  is made of an electrically conductive material. In particular, many embodiments of lanyard tag  350  will have a lanyard  351  having its core made of an electrically conductive cable. Coupler end  353  of lanyard  351  has a retention pin  354  section and a contact cylinder  355  section. To retain lanyard tag  350  on an article, lanyard  351  is passed through the article and retention pin  354  is inserted into aperture  356 , where it is retained by a mechanism located in lanyard tag  350 . Alternatively to passing lanyard  351  through an article, lanyard  351  may be passed around some location on an article where it may not be easily removed. In one embodiment of tag  350 , the mechanism that retains retention pin  354  in aperture  356  is a ball clutch which can be made to release retention pin  354  by application of a strong magnetic force to clutch cone  357  visible on the bottom of lanyard tag  350  in  FIGS. 8 ,  10 , and  11 . In some embodiments, clutch housing  358 , visible in  FIG. 11 , has at least some magnetically attractable material in it, and is the element acted upon by the strong magnetic force to release retention pin  354 . 
         [0050]    Depending on the specific embodiment, lanyard tag, or lanyard transponder  350 , may have several more features or elements in addition to those already discussed. Visible externally in  FIG. 8  are two possible elements; an infrared communication port  359  and a light emitting diode (LED)  360 . Infrared communication port  359  and LED  360  are also visible in  FIG. 11 , while only LEI)  360  is visible in  FIG. 10 . Visible in  FIG. 11  are additional possible elements internal to lanyard tag  350 . These additional possible internal elements include; switch  361 , battery  362 , circuit board  363  with microprocessor, clock, and communication antenna components (microprocessor, clock, and communication antenna components are not visible in  FIG. 11 ), audible alarm generator  364 , and EAS ferrite  365 . While the embodiment of lanyard tag  350  shown in  FIG. 11  has an EAS ferrite  365 , other embodiments might use a resonator, which is a common detectable element used in EAS tags. Another possible element that may accompany audible alarm generator  364 , is sound vent  366 , most visible in  FIG. 6 . Sound vent  366  allows the alarm to be more audible by allowing a path for sound to leave tag  350 . Finally, clutch wire  367  runs from circuit board  363  to retention element  368 , and lanyard wire  369  runs from circuit board  363  to anchored end  352  of lanyard  351 . Clutch wire  367 , lanyard wire  369 , and switch  361  form circuits that assist with detecting physical tampering with lanyard tag  350 . 
         [0051]    Lanyard tag  350  is capable of self alarming upon the occurrence of any one of several events. One event that can trigger self alarming by tag  350  is physical tampering with the tag. A common attack used against lanyard type tags is the cutting of the lanyard. Referring to  FIG. 111 , once coupler end  353  of lanyard  351  is inserted through aperture  356  and into retention mechanism  368 , two tamper detection circuits are completed. A first tamper detection circuit includes clutch wire  367 , retention mechanism  368 , retention pin  354 , contact cylinder  355 , and switch  361  and is completed on circuit board  363  (microprocessor, etc.). This first tamper detection circuit establishes that coupler end  353  of lanyard  351  has been inserted. A second tamper detection circuit includes lanyard wire  369 , lanyard  351  and can be completed by two possible routes. One completion route includes contact cylinder  355 , switch  361 , and circuit board  363  (microprocessor etc.). Another completion route includes retention pin  354 , retention mechanism  368 , clutch wire  367  and circuit board  363  (microprocessor, etc.). This second tamper detection circuit monitors the integrity of lanyard  351 . If lanyard  351  is cut, the first tamper detection circuit is still completed, while the second detection circuit is opened. When tag  350  detects that lanyard  351  has been cut, it self alarms with audible alarm generator  313  generating an audible sound. In addition to self alarming, tag  350  can also notify the system that a tag has been tampered with via the RAD unit closest to the damaged tag. Tag  350  communicates with RAD units  20  with communication antenna components located on circuit board  363  and can also be instructed to cease alarming by the system via the RAD units. Some embodiments of tag  350  will self alarm when the body of tag  350  is opened or otherwise compromised. In this case the self alarm may be triggered by the displacement of circuit board  363  or other means. 
         [0052]    Another event that can trigger an alarm by the audible alarm generator  364  on board tag  350  is instruction to do so by a RAD unit. This can occur when a RAD generates a response from tag  350  and the RAD unit is programmed to instruct tag  350  to self alarm because that RAD unit is monitoring a sensitive area such as an exit and therefore tag  350  is in a sensitive area. For example, referring to  FIG. 1 , the RAD units  20  located near exit  70  can be programmed distinctly from RAD units not located as close to exit  70 . RAD units  20  located near exit  70  can be programmed to instruct tags  350  in communication with those RAD units to self alarm. 
         [0053]    A further event that may cause some embodiments of tag  350  to self alarm is interaction with more basic electronic article surveillance systems through ferrite  365 , or a resonator, in some embodiments. EAS systems generate interrogation fields, usually near exits. These interrogation fields are electromagnetic fields in the radio frequency range of electromagnetic waves typically in the 58 kHz area. However a system may operate on any number of frequencies other than 58 kHz. While the interrogation field is being generated, it develops stored energy in ferrite  365 , or a resonator, in tag  350 . When the interrogation field is no longer being generated and the electronic article surveillance system is monitoring for a signal, the energy stored in ferrite  365 , dissipates and generates a signal in the process. This signal is detected by the monitoring EAS system. Detection of tag  350  by an article surveillance system will cause the article surveillance system to generate a system alarm, audible or otherwise. However, the activity in ferrite  365  is also detectable by circuit board  363  which can trigger a self alarm by tag  350 . 
         [0054]    All in all, there are several ways that various embodiments of tag  350  can generate alarms. Tag  350  can self alarm with its on board audible alarm generator  364  when tampered with. Tag  350  can self alarm with its on board audible alarm generator  364  when instructed to by a RAD unit. Tag  350  can self alarm with its on board audible alarm generator  364  when it detects that an onboard electronic article surveillance element such as a ferrite  365 , or a resonator, is being stimulated by an electronic article surveillance interrogation zone. An article surveillance system can also generate a system alarm when it detects the presence of a tag  350  having an electronic article surveillance ferrite, or resonator,  365 . In some cases, RAD unit  20  can instruct tag  350  to cease to self alarm. 
         [0055]    The microprocessor located in transponders  30 , such as tag  300  and lanyard tag  350 , and other embodiments, is capable of storing information, being reprogrammed, and performing functions through other elements in transponders  30  such as discussed as being in tag  300  and lanyard tag  350 . The microprocessor can store a wide range of information communicated to it by supporting systems via radio signals, etc. For example, when a tag is attached to an article, information about that article can be transmitted to the tag and stored. In some embodiments, other, particularly important, pieces of information that a microprocessor might store includes a unique identifier associated with the respective tag and a password. The unique identifier may initially be assigned at a factory and may be altered on location when put into use. When queried by a system, the microprocessor responds with its ID, or other solicited information, via the tag&#39;s communications elements, antennas etc. As will be explained, in embodiments employing a password, the password can provide additional security in conjunction with the unique identifier, or ID, by adding an additional system element wherein a device used to detach or disarm a tag, or to instruct a tag to stop self alarming, must be able to verify a password to be able to execute the operation. For example, some transponders may be release from an article to which they are attached by the application of a strong magnetic force. Without the need for verification from the EAS system, a transponder can be detached by the application of a large unauthorized magnet. Requiring interaction with the system, such as password verification, before detaching the tag allows the microprocessor to be programmed to alarm when it is detached with no system interaction or password exchange. 
         [0056]    Transponder embodiments employing a password may a have static, unchanging password or may employ a changeable password. Passwords that can be changed can be changed by computer via a universal serial bus (USB), by wireless infrared device, or the tag can automatically change the password using a time-based algorithm programmed into the tag&#39;s microprocessor. For tags automatically changing their passwords, other system elements, such as the server will have the same algorithm as the tag and be able to duplicate and track the password changes for each particular tag. Other system elements, such as a base station will have the same algorithm as the tag and be able to duplicate and track the password changes for each particular tag. 
         [0057]    Embodiments using a time-based algorithm programmed into the tag&#39;s microprocessor to change the password will do so periodically. In one embodiment, transponders  30 , have a highly accurate clock onboard along with the microprocessor. The microprocessor is programmed with an algorithm for changing the password for the tag and the clock is used to determine when the password should be changed according to the protocols programmed into the microprocessor. The system includes a server capable of running software. The server also has an accurate clock and possesses the algorithm programmed into the microprocessor of the tag. By knowing the initial password of a tag and marking an initial time, the server of the system can update its database to contain the correct password of a given tag as the password is changed. 
         [0058]    Of course if the password of a transponder is changed directly by a server or RAD unit, then the password of that transponder is known to other elements of the system and the database is updated at the time of the password change. In one system embodiment, a system wide password is used and no unique transponder identifiers are needed. When the password is changed it is changed for all elements of the system, transponders, RAD units, and server. In an embodiment using a time based algorithm to periodically change passwords, all elements of the system have access to high accuracy clocks. The system elements are chronologically synchronized and the password is internally changed in each element. When system elements communicate, they each have the correct updated password. 
         [0059]    For a transponder, or tag, using a password to be released from an article without generating an alarm, an element of the system, such as a RAD unit, must communicate with the transponder, confirm the password, and instruct the transponder microprocessor. A special tool combining microprocessor and communication capabilities with the ability to generate a strong magnetic force can unlock, or detach, a transponder while altering its settings to not alarm. 
         [0060]    If a tag, or transponder, is not disarmed by a system element such as, for example, a RAD unit, it will alarm when detached. If the tag is not first disarmed by a system element, the tag will self-alarm when it is tampered with (forced open or a lanyard cut). If the tag is not first disarmed by a system element before it enters the interrogation field of an EAS system, the tag will self-alarm. If the tag enters the interrogation field of an EAS system, the tag will cause the EAS system to alarm. 
         [0061]    While several embodiments are discussed in this specification, these are for illustrative purposes and should not be taken as a limiting description of the invention. As can be understood from the above description, the asset protection system can have a wide range of embodiments, as indicated with respect to specific elements and of the asset protection system  10 . These elements include the RAD units  20 , transponders  30 , the software functions, as well as how the various elements are physically arranged with respect to each other. The modular aspect and ease of connectivity of the RAD units  20  provides simple setup, even in environments that are cluttered and fully developed, because there is no need to access standard AC power, or run antennas, etc.