EAS tag polling system

• US 20060203838A1
• Filed: 03/08/2005
• Published: 09/14/2006
• Est. Priority Date: 03/08/2005
• Status: Active Grant

• Current Assignee: InPoint Systems, Inc.
• Original Assignee: InPoint Systems, Inc.
• Inventors: Howard, Richard E., Fenson, Eitan M.
• Granted Patent: US 7,755,485 B2
• Time in Patent Office: Days
• US Class Current: 370/449
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00
• CPC Class Codes: G08B 13/2482 EAS methods, e.g. description of flow chart of the detection procedure
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

An EAS tag polling system includes a plurality of EAS tags and a base station, wherein each of the tags transmits an acknowledgement to the base station. The base acknowledgments may be sent passively or actively in response to a request from the base station. The base station discriminates between each acknowledgment received and associates it to the tag from which it had been transmitted. From each acknowledgement received, the base station indicates that a positive response is associated with each of the tags from which the acknowledgement is received and a negative response is associated with each of the tags from which the acknowledgement is not received.

Claims

1. An EAS tag polling system comprising:

a plurality of EAS tags, each of said tags being operative to transmit an acknowledgement having an identifying characteristic; and

a base station being knowledgeable of said identifying characteristic of said acknowledgement to discriminate between said acknowledgement transmitted from each of said tags and operative to indicate that a positive response is associated with each of said tags from which said acknowledgement is received and a negative response is associated with each of said tags from which said acknowledgement is not received.

2. An EAS tag polling system as set forth in claim 1 further comprising at least one repeater operationally interposed at least one of said tags and said base station such that a transmission range of said at least one of said tags is extended to said base station.

3. An EAS tag polling system as set forth in claim 2 further comprising at least one further repeater operationally interposed said at least one repeater and said base station such that said transmission range of said at least one of said tags is further extended to said base station.

4. An EAS tag polling system as set forth in claim 1 wherein each of said tags is further operative to transmit said acknowledgment with a preselected temporality.

5. An EAS tag polling system as set forth in claim 4 wherein each of said tags is operative to transmit said acknowledgement with a continuous temporality.

6. An EAS tag polling system as set forth in claim 4 wherein each of said tags is operative to transmit said acknowledgement with a periodic temporality.

7. An EAS tag polling system as set forth in claim 4 wherein each of said tags is operative to transmit said acknowledgement with an intermittent temporality.

8. An EAS tag polling system as set forth in claim 4 wherein each of said tags is operative to transmit said acknowledgement with a random temporality.

9. An EAS tag polling system as set forth in claim 4 wherein each of said tags is operative to transmit said acknowledgement with a selectively on demand temporality.

10. An EAS tag polling system as set forth in claim 4 wherein said temporality differs between a first group of said tags and a second group of said tags.

11. An EAS tag polling system as set forth in claim 1 wherein said positive response is minimally indicative that each of said tags with which said positive response is associated is present and operable within said system.

12. An EAS tag polling system as set forth in claim 11 wherein said acknowledgment transmitted from each of said tags is a selected one of a frequency burst and a pulse.

13. An EAS tag polling system as set forth in claim 1 wherein said acknowledgment transmitted from each of said tags further includes an informational characteristic, said base station being further knowledgeable of and operative to verify said informational characteristic in said acknowledgment transmitted from each of said tags such that said negative response is associated with anyone of said tags for which said informational characteristic in said acknowledgment transmitted therefrom fails verification.

14. An EAS tag polling system as set forth in claim 1 wherein said identifying characteristic is a different code for said acknowledgement transmitted from each respective one of said tags.

15. An EAS tag polling system is set forth in claim 14 wherein said base station is operative to discriminate between said acknowledgement transmitted from each one of said tags using code division multiple access protocols.

16. An EAS tag polling system as set forth in claim 1 wherein said identifying characteristic is a different frequency for each acknowledgement transmitted from each respective one of said tags.

17. An EAS tag polling system as set forth in claim 16 wherein said base station is operative to discriminate between said acknowledgement transmitted from each one of said tags using frequency division multiple access protocols.

18. An EAS tag polling system as set forth in claim 1 wherein said identifying characteristic is a different time slot for each acknowledgement transmitted from each respective one of said tags.

19. An EAS tag polling system as set forth in claim 8 wherein said base station is operative to discriminate between said acknowledgement transmitted from each one of said tags using time division multiple access protocols.

20. An EAS tag polling system as set forth in claim 1 wherein said identifying characteristic is a key uniquely identifying each respective one of said tags placed in said acknowledgement transmitted from each respective one of said tags.

21. An EAS tag polling system as set forth in claim 20 wherein each of said tags includes a memory, said key being stored in said memory.

22. An EAS tag polling system as set forth in claim 21 wherein said memory is nonvolatile.

23. An EAS tag polling system as set forth in claim 21 wherein said memory is flash memory.

24. An EAS tag polling system as set forth in claim 21 wherein each of said tags further includes a tag transmitter, said key being applied to said tag transmitter in each of said tags, said tag transmitter in each of said tags being operative to transmit said acknowledgment from each of said tags.

25. An EAS tag polling system as set forth in claim 24 wherein said acknowledgment transmitted from each of said tags is minimally said key unique to each of said tags.

26. An EAS tag polling system as set forth in claim 20 wherein said base station includes a base station receiver which receives said acknowledgment transmitted from each of said tags, a processor which reads said key received at said base station receiver, and a lookup table having a plurality of key entries corresponding to each respective one of said tags, said processor further accessing said lookup table to ascertain whether said key read by said processor corresponds to one of said key entries.

27. An EAS tag polling system as set forth in claim 26 wherein in the event said key read by said processor corresponds to said one of said key entries said processor sets a flag associated with said one of said key entries, said flag being an indication that said positive response is associated with one of said tags to which said one of said key entries respectively corresponds.

28. An EAS tag polling system as set forth in claim 1 wherein each of said tags is further operative to develop a timing pulse, said acknowledgment being transmitted from each of said tags in response to said timing pulse.

29. An EAS tag polling system as set forth in claim 28 wherein each of said tags includes the tag transmitter and a clock counter to provide a binary count of a number of clock pulses applied thereto, said clock counter having a plurality of output bits, said timing pulse being developed in response to a selected one of said output bits transitioning from a first binary state to a second binary state, said tag transmitter transmitting said acknowledgment in response to said timing pulse.

30. An EAS tag polling system as set forth in claim 29 wherein said timing pulse is developed in response to a logical combination of selected ones of said output bits transitioning from said first binary state to said second binary state.

31. An EAS tag polling system as set forth in claim 29 wherein said selected one of said output bits is the same in each of said tags.

32. An EAS tag polling system as set forth in claim 29 wherein said selected one of said output bits is different in each of said tags.

33. An EAS tag polling system as set forth in claim 29 wherein said selected one of said output bits is the same in one group of said tags but different from said selected one of said output bits in another group of said tags.

34. An EAS tag polling system as set forth in claim 29 wherein each of said tags further includes a clock to develop said clock pulses.

35. An EAS tag polling system as set forth in claim 29 wherein said base station includes a clock to develop said clock pulses and a base station transmitter to which said clock pulses are applied and wherein each of said tags further includes a tag receiver, said base station transmitter transmitting said clock pulses, said tag receiver receiving said clock pulses and applying said clock pulses to said clock counter.

36. An EAS tag polling system as set forth in claim 35 wherein said tag receiver further converts RF energy of the carrier of said clock pulses to DC power.

37. An EAS tag polling system as set forth in claim 1 wherein said base station is further operative to transmit a sync pulse, each of said tags being responsive to said sync pulse to transmit said acknowledgement.

38. An EAS tag polling system as set forth in claim 37 wherein said base station includes a base station transmitter and a clock counter to provide a binary count of a number of clock pulses applied thereto and wherein each of said tags includes a tag receiver and a tag transmitter, said clock counter having a plurality of output bits, said sync pulse being developed in response to a selected one of said output bits transitioning from a first binary state to a second binary state, said sync pulse being transmitted by said base station transmitter and received by said tag receiver, said tag receiver applying said sync pulse to said tag transmitter, said tag transmitter transmitting said acknowledgment in response to said sync pulse.

39. An EAS tag polling system as set forth in claim 38 wherein said sync pulse is developed in response to a logical combination of selected ones of said output bits transitioning from said first binary state to said second binary state.

40. An EAS tag polling system as set forth in claim 38 wherein said base station further includes a clock to develop said clock pulses.

41. An EAS tag polling system as set forth in claim 37 wherein each of said tags is operative to transmit said acknowledgment after a selected time delay from receipt of said sync pulse wherein said time delay for each of said tags is selected such that said acknowledgement transmitted from each of said tags is received in succession at said base station.

42. An EAS tag polling system as set forth in claim 41 wherein each of said tags includes a tag receiver, a clock counter to provide a binary count of a number of clock pulses applied thereto, said clock counter having a reset input and the plurality of output bits, said sync pulse being received by said tag receiver and said tag receiver applying said sync pulse to said reset input, said tag transmitter transmitting said acknowledgment in response to a timing pulse developed upon said selected one of said output bits changing state.

43. An EAS tag polling system as set forth in claim 42 wherein said selected one of said output bits is different in each one of said tags.

44. An EAS tag polling system as set forth in claim 1 wherein for one of said tags with which said positive response has been associated, said base station is further operative to determine that said negative response is to be associated with said one of said tags in the event said acknowledgement ceases to be received from said one of said tags.

45. An EAS tag polling system as set forth in claim 44 wherein said negative response is associated with said one of said tags upon expiration of a selected time duration from last receipt of said acknowledgement received from said one of said tags.

46. An EAS tag polling system as set forth in claim 44 wherein said one of said tags is operative to transmit said acknowledgment there from with a preselected temporality, said selected time duration being commensurate with said temporality.

47. An EAS tag polling system as set forth in claim 46 wherein each of said tags is operative to transmit periodically said acknowledgement, said selected time duration being commensurate with a periodicity of said acknowledgement.

48. An EAS tag polling system as set forth in claim 44 wherein said base station is further operative to transmit a request to said one of said tags from which said acknowledgement is not received prior to said negative response being associated with said one of said tags, said one of said tags being further operative in response to said request to retransmit said acknowledgment, said base station being further operative to indicate that said positive response is associated with said one of said tags in the event said retransmited acknowledgment is received by said base station and said negative response is associated with said one of said tags in the event said retransmited acknowledgment is not received by said base station.

49. An EAS tag polling system as set forth in claim 48 wherein said request includes an identifying characteristic, said one of said tags being further operative to verify that said identifying characteristic of said request corresponds to said identifying characteristic of said acknowledgment transmitted from said one of said tags such that upon verification said one of said tags is operative to retransmit said acknowledgment.

50. An EAS tag polling system as set forth in claim 49 wherein said identifying characteristic in each of said request and said acknowledgment transmitted from said one of said tags is a key uniquely identifying said one of said tags.

51. An EAS tag polling system as set forth in claim 44 wherein said base station includes a processor and a clock counter to which a plurality of clock pulses are applied, said clock counter having a reset input and a plurality of output bits at which a count of said clock pulses is developed, said processor applying a reset pulse to said reset input upon said processor setting a flag to indicate that said positive response has been associated with said one of said tags, said negative response to be associated with said one of said tags upon a selected one of said output bits transitioning from a first binary state to a second binary state.

52. An EAS tag polling system as set forth in claim 51 wherein said processor removes said flag in response to said selected one of said output bits transitioning from said first binary state to said second binary state.

53. An EAS tag polling system as set forth in claim 51 wherein said processor is further operative to develop a request to retransmit said acknowledgment wherein said request is to be transmitted to said one of said tags in response to said selected one of said output bits transitioning from said first binary state to said second binary state.

54. An EAS tag polling system as set forth in claim 53 wherein said processor maintains said flag in the event a retransmitted acknowledgment is received from said one of said tags in response to said request such that said positive response continues to be associated with said one of said tags.

55. An EAS tag polling system as set forth in claim 54 wherein said processor applies a reset pulse to said clock counter upon said retransmitted acknowledgment being received by said base station.

56. An EAS tag polling system as set forth in claim 53 wherein said processor remove said flag in the event said retransmitted acknowledgement is not received by said base station in response to said request such that said negative response is associated with said one of said tags.

57. An EAS tag polling system as set forth in claim 53 wherein said base station further includes a lookup table having a plurality of key entries, each of said key entries respectively being a key for each one of said tags, said processor accessing said lookup table to read said key for said one of said tags to develop said request wherein said request includes said key.

58. An EAS tag polling system is set forth in claim 1 wherein said base station is further operative to transmit a request, each of said tags being operative in response to said request to transmit said acknowledgement therefrom.

59. An EAS tag polling system as set forth in claim 58 wherein said request includes a key, each of said tags being further operative to verify said key and to transmit said acknowledgement only in the event said key is verified.

60. An EAS tag polling system as set forth in claim 59 wherein each of said tags includes a key lock circuit and a receiver operative to receive said request and to apply said key to said key lock circuit, said key lock circuit being operative to verify said key.

61. An EAS tag polling system as set forth in claim 59 wherein said key is unique for each respective one of said tags.

62. An EAS tag polling system as set forth in claim 61 wherein said key is a standard address for each respective one of said tags, said base station being operative to transmit said request to each individual one of said tags identified by said standard address.

63. An EAS tag polling system as set forth in claim 59 wherein said key is one of a plurality of keys derived from a master key for each respective one of said tags, each respective one of said tags being further operative to decode said plurality of keys to said master key, each of said tags being operative to verify said master key and transmit said acknowledgment only in the event said master key is verified.

64. An EAS tag polling system as set forth in claim 1 wherein said acknowledgement transmitted from each one of said tags further has an informational characteristic, said base station being knowledgeable of said informational characteristic of said acknowledgement transmitted from each one of said tags and, with respect to each of said tags for which said acknowledgement is received at said base station, further operative to indicate said positive response is associated with each of said tags for which said informational characteristic of said acknowledgement is valid and said negative response is associated with each of said tags for which said informational characteristic of said acknowledgement is invalid.

65. An EAS tag polling system as set forth in claim 64 wherein said informational characteristic is data content of said acknowledgement.

66. An EAS tag polling system as set forth in claim 64 wherein said base station is further operative to verify said data content in said acknowledgement received from each of said tags such that when verified said data content is valid and when not verified said data content is invalid.

67. An EAS tag polling system as set forth in claim 66 wherein said data content is identical for each of said tags.

68. An EAS tag polling system as set forth in claim 66 wherein said data content is different for each of said tags.

69. An EAS tag polling system as set forth in claim 66 wherein said data content for each of said tags is invariant.

70. An EAS tag polling system as set forth in claim 69 wherein said data content for each of said tags is a preselected bit string.

71. An EAS tag polling system as set forth in claim 70 wherein said informational characteristic is a bit pattern of said preselected bit string, said base station recognizing said bit pattern to verify said data content.

72. An EAS tag polling system as set forth in claim 66 wherein said data content for each of said tags is variant in accordance with a function that implements an algorithm, said base station being knowledgeable of said function to verify said data content.

73. An EAS tag polling system as set forth in claim 72 wherein said data content for each of said tags is variant as a function of time.

74. An EAS tag polling system as set forth in claim 72 wherein said data content for each one of said tags is variant as a function of a number of instances said acknowledgement is transmitted from a same one of said tags.

75. An EAS tag polling system as set forth in claim 72 wherein said data content for each of said tags is developed in accordance with said function from a seed used by said algorithm.

76. An EAS tag polling system as set forth in claim 75 wherein said seed value is stored in each of said tags.

77. An EAS tag polling system as set forth in claim 76 wherein said seed value is identical in each of said tags.

78. An EAS tag polling system as set forth in claim 76 wherein said seed value is different in each of said tags.

79. An EAS tag polling system as set forth in claim 76 wherein said seed value is an initialized bit string.

80. An EAS tag polling system as set forth in claim 76 wherein said base station is further knowledgeable of said seed value stored in each of said tags to develop expected data content with which to verify said data content in said acknowledgment received from each of said tags.

81. An EAS tag polling system as set forth in claim 80 wherein said base station is further operative to compare said expected data content to said data content in said acknowledgment received from each of said tags wherein said positive response is associated with each of said tags for which the comparison is positive and said negative response is associated with each of said tags for which the comparison is negative.

82. An EAS tag polling system as set forth in claim 75 wherein each one of said tags includes a memory in which said seed is stored, a tag clock counter to which a succession of clock pulses is applied and having a plurality of output bits at which a count of said clock pulses is developed, a logic circuit to which each of said seed and at least one of said output bits of said count are applied to develop an output bit string applied to said transmitter, said transmitter being operative to transmit said acknowledgement wherein said output bit string is said data content in said acknowledgment.

83. An EAS tag polling system as set forth in claim 82 wherein each of said tags further includes a register into which said output bit string is serially clocked and further wherein contents of said register is applied to said transmitter in response to a timing pulse.

84. An EAS tag polling system as set forth in claim 83 wherein a current value of said at least one of said output bits of said clock counter is added to the contents of said register upon said timing pulse being developed such that said data content contains said at least one of said output bits and the contents of said register.

85. An EAS tag polling system as set forth in claim 84 wherein a current value of said output bits is added to the contents of said register.

86. An EAS tag polling system as set forth in claim 83 wherein said timing pulse is developed in response to a selected one of said output bits of said clock counter transitioning from a first binary state to a second binary state.

87. An EAS tag polling system as set forth in claim 82 wherein each of said tags further includes a clock to develop said succession of clock pulses.

88. An EAS tag polling system as set forth in claim 82 wherein said base station includes a processor, a lookup table containing a seed associated with each of said tags, a clock to develop said succession of clock pulses, a base station clock counter having a plurality of output bits at which a count of said clock pulses is developed and a transmitter operative to transmit said clock pulses to each of said tags, each of said tags further including a receiver to receive said clock pulses and to apply said clock pulses to said tag clock counter, said base station clock counter developing a value at at least one of said output bits of said base station clock counter in lockstep with said at least one of said output bits of said tag clock counter, said processor developing expected data content from each of said seed in said lookup table associated with said one of said tags and said at least one of said output bits of said base station clock counter in accordance with said algorithm as implemented by said logic circuit, said processor verifying said data content in said acknowledgment received from each of said tags to said expected data content developed for each of said tags.

89. An EAS tag polling system as set forth in claim 88 wherein said processor is further operative to develop a sync pulse to reset each of said base station clock counter and said tag clock counter in each of said tags, each of said tags being responsive to said sync pulse to reset said counter.

90. An EAS tag polling system as set forth in claim 89 wherein said base station further includes a transmitter to transmit said sync pulse to each of said tags and wherein each of said tags further includes a receiver operative to receive said sync pulse and to apply said sync pulse to said counter.

91. An EAS tag polling system as set forth in claim 75 wherein each respective one of said tags includes a memory in which said seed is stored, an instance counter having a plurality of output bits at which a count of a number of instances of said acknowledgement has been transmitted from said respective one of said tags, a logic circuit to which each of said seed and said count are applied and operative to develop an output bit string, and a transmitter to which said output bit string is applied, said transmitter being operative to transmit said acknowledgement.

92. An EAS tag polling system as set forth in claim 91 wherein each of said tags further includes a register into which said output bit string is serially clocked and further wherein contents of said register is applied to said transmitter in response to a timing pulse.

93. An EAS tag polling system as set forth in claim 92 wherein said instance counter is incremented in response to said timing pulse.

94. An EAS tag polling system is set forth in claim 92 wherein each respective one of said tags further includes a clock counter to which a succession of clock pulses is applied to develop a binary count of said clock pulses, said clock counter having a selected output bit, said timing pulse being developed in response to said selected output bit transitioning from a first binary state to a second binary state.

95. An EAS tag polling system as set forth in claim 94 wherein each of said tags further includes a clock to develop said succession of clock pulses.

96. An EAS tag polling system as set forth in claim 94 wherein said base station includes a clock to develop said succession of clock pulses and a transmitter operative to transmit said clock pulses to each of said tags, each of said tags further including a receiver to receive said clock pulses and to apply said clock pulses to said clock counter.

97. An EAS tag polling system as set forth in claim 91 wherein said base station is further operative to develop a sync pulse, each of said tags being responsive to said sync pulse to reset said instance counter.

98. An EAS tag polling system as set forth in claim 97 wherein each of said tags further includes a receiver operative to receive said sync pulse and to apply said sync pulse to said instance counter.

99. An EAS tag polling system as set forth in claim 75 wherein each of said tags includes:

a n-bit wide shift register having a plurality of cascaded gates, said seed being applied as a bit string to said shift register, each of said gates having a Q output and a {overscore (Q)} output; and

a logic circuit having a plurality of inputs and an output, each of said inputs being connected to a selected one of said Q output and said {overscore (Q)} output of a corresponding one of said gates, said data content of said acknowledgement being an output bit string developed at said output.

100. An EAS tag polling system as set forth in claim 99 wherein each of said tags further includes a memory to store said seed.

101. An EAS tag polling system as set forth in claim 99 wherein said seed is transmitted to each of said tags by said base station.

102. An EAS tag polling system as set forth in claim 99 wherein a number of said inputs is less than a number of said gates.

103. An EAS tag polling system as set forth in claim 99 wherein each of said gates further has a D input, said D input being selectively connected to one of said Q output and said {overscore (Q)} output of an immediately preceding one of said gates.

104. An EAS tag polling system as set forth in claim 99 further comprising a standard gate to which said seed and an output bit of a selected one of said Q output and said {overscore (Q)} output of a least significant one of said gates are applied.

105. An EAS tag polling system as set forth in claim 99 wherein each of said tags further includes:

a buffer containing said output bit string from said output;

a counter containing a count of a selected one of clock pulses applied to said counter and each instance of said acknowledgement being transmitted from each respective one of said tags, said counter having a plurality of output bits; and

a second logic circuit operative to combine logically said output bit string in said buffer with at least one of said output bits of said counter whereby said data content for said acknowledgement for each respective one of said tags is developed.

106. An EAS tag polling system as set forth in claim 99 wherein said seed is bitwise clocked into said shift register such that each bit of said output bit string is developed as each bit of said seed is applied to said shift register.

107. An EAS tag polling system as set forth in claim 106 wherein each of said tags further includes a tag transmitter, said output bit string being bitwise applied to said transmitter.

108. An EAS tag polling system as set forth in claim 99 wherein said base station is further knowledgeable of said seed value stored in each of said tags to develop expected data content with which to verify said data content in said acknowledgment received from each of said tags.

109. An EAS tag polling system as set forth in claim 108 wherein said base station is further operative to compare said expected data content to said data content in said acknowledgment received from each of said tags wherein said positive response is associated with each of said tags for which the comparison is positive and said negative response is associated with each of said tags for which the comparison is negative.

110. An EAS tag polling system as set forth in claim 109 wherein said base station includes a receiver to receive said acknowledgement from each one of said tags and a processor operative to read said data content in said acknowledgement from each one of said tags and compare said data content to said expected data for each one of said tags.

111. An EAS tag polling system as set forth in claim 108 wherein said processor is further operative to generate contemporaneously said expected data for each one of said tags.

112. An EAS tag polling system is set forth in claim 64 wherein said base station is further operative to transmit a request, said request including an informational characteristic, each one of said tags being further operative to develop said informational characteristic of said acknowledgement transmitted from each respective one of said tags as a function of said informational characteristic of said request.

113. An EAS tag polling system comprising:

a plurality of EAS tags, each of said tags being operative in response to a request to transmit an acknowledgment; and

a base station operative to transmit said request in a manner which allows said base station to discriminate between said acknowledgment transmitted from each of said tags and operative to indicate that a positive response is associated with each of said tags from which said acknowledgment is received and a negative response is associated with each of said tags for which said acknowledgment is not received.

114. An EAS tag polling system as set forth in claim 113 further comprising at least one repeater operationally interposed at least one of said tags and said base station such that a transmission range of said one of at least one of said tags and said base station is extended to an other one of said at least one of said tags and said base station.

115. An EAS tag polling system as set forth in claim 114 further comprising at least one further repeater operationally interposed said at least one repeater and said base station such that said transmission range of said one of said at least one of said tags and said base station is further extended to said other one of said at least one of said tags and said base station.

116. An EAS tag polling system as set forth in claim 113 wherein said base station is further operative to transmit said request with a preselected temporality.

117. An EAS tag polling system as set forth in claim 116 wherein said base station is operative to transmit said request with a continuous temporality.

118. An EAS tag polling system as set forth in claim 116 wherein said base station is operative to transmit said request with a periodic temporality.

119. An EAS tag polling system as set forth in claim 116 wherein said base station is operative to transmit said request with an intermittent temporality.

120. An EAS tag polling system as set forth in claim 116 wherein said base station is operative to transmit said request with a random temporality.

121. An EAS tag polling system as set forth in claim 116 wherein said base station is operative to transmit said request with a selectively on demand temporality.

122. An EAS tag polling system as set forth in claim 116 wherein said temporality differs between said request transmitted to a first group of said tags and said request transmitted to a second group of said tags.

123. An EAS tag polling system as set forth in claim 113 wherein said positive response is minimally indicative that each of said tags with which said positive response is associated is present and operable within said system.

124. An EAS tag polling system as set forth in claim 123 wherein said acknowledgment transmitted from each of said tags is a selected one of a frequency burst and a pulse.

125. An EAS tag polling system as set forth in claim 113 wherein said acknowledgment transmitted from each of said tags further includes an informational characteristic, said base station being further knowledgeable of and operative to verify said informational characteristic in said acknowledgment transmitted from each of said tags such that said negative response is associated with anyone of said tags for which said informational characteristic in said acknowledgment transmitted therefrom fails verification.

126. An EAS tag polling system as set forth in claim 113 wherein said acknowledgment transmitted from each one of said tags includes an identifying characteristic associated with each one of said tags.

127. An EAS tag polling system as set forth in claim 126 wherein said identifying characteristic is a key uniquely identifying each respective one of said tags placed in said acknowledgement transmitted from each respective one of said tags.

128. An EAS tag polling system as set forth in claim 127 wherein each of said tags includes a memory, said key being stored in said memory.

129. An EAS tag polling system as set forth in claim 128 wherein said memory is nonvolatile.

130. An EAS tag polling system as set forth in claim 128 wherein said memory is flash memory.

131. An EAS tag polling system as set forth in claim 128 wherein each of said tags further includes a tag transmitter, said key being applied to said tag transmitter in each of said tags, said tag transmitter in each of said tags being operative to transmit said acknowledgment from each of said tags.

132. An EAS tag polling system as set forth in claim 131 wherein said acknowledgment transmitted from each of said tags is minimally said key unique to each of said tags.

133. An EAS tag polling system as set forth in claim 127 wherein said base station includes a base station receiver which receives said acknowledgment transmitted from each of said tags, a processor which reads said key received at said base station receiver, and a lookup table having a plurality of key entries corresponding to each respective one of said tags, said processor further accessing said lookup table to ascertain whether said key read by said processor corresponds to one of said key entries.

134. An EAS tag polling system as set forth in claim 133 wherein in the event said key read by said processor corresponds to said one of said key entries said processor sets a flag associated with said one of said key entries, said flag being an indication that said positive response is associated with one of said tags to which said one of said key entries respectively corresponds.

135. An EAS tag polling system as set forth in claim 113 wherein each of said tags is further operative to develop a timing pulse upon receipt of said request, said acknowledgment being transmitted from each of said tags in response to said timing pulse.

136. An EAS tag polling system as set forth in claim 135 wherein each of said tags includes the tag transmitter and a clock counter to provide a binary count of a number of clock pulses applied thereto, said clock counter having a plurality of output bits, said timing pulse being developed in response to a selected one of said output bits transitioning from a first binary state to a second binary state, said tag transmitter transmitting said acknowledgment in response to said timing pulse.

137. An EAS tag polling system as set forth in claim 136 wherein said timing pulse is developed in response to a logical combination of selected ones of said output bits transitioning from said first binary state to said second binary state.

138. An EAS tag polling system as set forth in claim 136 wherein said selected one of said output bits is the same in each of said tags.

139. An EAS tag polling system as set forth in claim 136 wherein said selected one of said output bits is different in each of said tags.

140. An EAS tag polling system as set forth in claim 136 wherein said selected one of said output bits is the same in one group of said tags but different from said selected one of said output bits in another group of said tags.

141. An EAS tag polling system as set forth in claim 136 wherein each of said tags further includes a clock to develop said clock pulses.

142. An EAS tag polling system as set forth in claim 136 wherein said base station includes a clock to develop said clock pulses and a base station transmitter to which said clock pulses are applied and wherein each of said tags further includes a tag receiver, said base station transmitter transmitting said clock pulses, said tag receiver receiving said clock pulses and applying said clock pulses to said clock counter.

143. An EAS tag polling system as set forth in claim 142 wherein said tag receiver further converts RF energy of the carrier of said clock pulses to DC power.

144. An EAS tag polling system as set forth in claim 113 wherein for one of said tags with which said positive response has been associated, said base station is further operative to determine that said negative response is to be associated with said one of said tags in the event said acknowledgement ceases to be received from said one of said tags.

145. An EAS tag polling system as set forth in claim 144 wherein said negative response is associated with said one of said tags upon expiration of a selected time duration from last receipt of said acknowledgement received from said one of said tags.

146. An EAS tag polling system as set forth in claim 144 wherein said base station is operative to transmit said request there from with a preselected temporality, said selected time duration being commensurate with said temporality.

147. An EAS tag polling system as set forth in claim 146 wherein base station is operative to transmit periodically said request, said selected time duration being commensurate with a periodicity of said acknowledgement.

148. An EAS tag polling system as set forth in claim 144 wherein said base station is further operative to transmit a further request to said one of said tags from which said acknowledgement is not received prior to said negative response being associated with said one of said tags, said one of said tags being further operative in response to said further request to retransmit said acknowledgment, said base station being further operative to indicate that said positive response is associated with said one of said tags in the event said retransmited acknowledgment is received by said base station and said negative response is associated with said one of said tags in the event said retransmited acknowledgment is not received by said base station.

149. An EAS tag polling system as set forth in claim 148 wherein said further request includes an identifying characteristic, said one of said tags being further operative to verify that said identifying characteristic of said request corresponds to an identifying characteristic of said acknowledgment transmitted from said one of said tags such that upon verification said one of said tags is operative to retransmit said acknowledgment.

150. An EAS tag polling system as set forth in claim 149 wherein said identifying characteristic in each of said request and said acknowledgment transmitted from said one of said tags is a key uniquely identifying said one of said tags.

151. An EAS tag polling system as set forth in claim 144 wherein said base station includes a processor and a clock counter to which a plurality of clock pulses are applied, said clock counter having a reset input and a plurality of output bits at which a count of said clock pulses is developed, said processor applying a reset pulse to said reset input upon said processor setting a flag to indicate that said positive response has been associated with said one of said tags, said negative response to be associated with said one of said tags upon a selected one of said output bits transitioning from a first binary state to a second binary state.

152. An EAS tag polling system as set forth in claim 151 wherein said processor removes said flag in response to said selected one of said output bits transitioning from said first binary state to said second binary state.

153. An EAS tag polling system as set forth in claim 151 wherein said processor is further operative to develop a further request to retransmit said acknowledgment wherein said request is to be transmitted to said one of said tags in response to said selected one of said output bits transitioning from said first binary state to said second binary state.

154. An EAS tag polling system as set forth in claim 153 wherein said processor maintains said flag in the event a retransmitted acknowledgment is received from said one of said tags in response to said further request such that said positive response continues to be associated with said one of said tags.

155. An EAS tag polling system as set forth in claim 154 wherein said processor applies a reset pulse to said clock counter upon said retransmitted acknowledgment being received by said base station.

156. An EAS tag polling system as set forth in claim 153 wherein said processor remove said flag in the event said retransmitted acknowledgment is not received by said base station in response to said request such that said negative response is associated with said one of said tags.

157. An EAS tag polling system as set forth in claim 153 wherein said base station further includes a lookup table having a plurality of key entries, each of said key entries respectively being a key for each one of said tags, said processor accessing said lookup table to read said key for said one of said tags to develop said further request wherein said further request includes said key.

158. An EAS tag polling system as set forth in claim 113 wherein said request includes a key, each of said tags being further operative to verify said key and to transmit said acknowledgement only in the event said key is verified.

159. An EAS tag polling system as set forth in claim 158 wherein each of said tags includes a key lock circuit and a receiver operative to receive said request and to apply said key to said key lock circuit, said key lock circuit being operative to verify said key.

160. An EAS tag polling system as set forth in claim 158 wherein said key is unique for each respective one of said tags.

161. An EAS tag polling system as set forth in claim 160 wherein said key is a standard address for each respective one of said tags, said base station being operative to transmit said request to each individual one of said tags identified by said standard address.

162. An EAS tag polling system as set forth in claim 158 wherein said key is one of a plurality of keys derived from a master key for each respective one of said tags, each respective one of said tags being further operative to decode said plurality of keys to said master key, each of said tags being operative to verify said master key and transmit said acknowledgment only in the event said master key is verified.

163. An EAS tag polling system as set forth in claim 113 wherein said acknowledgement transmitted from each one of said tags further has an informational characteristic, said base station being knowledgeable of said informational characteristic of said acknowledgement transmitted from each one of said tags and, with respect to each of said tags for which said acknowledgement is received at said base station, further operative to indicate said positive response is associated with each of said tags for which said informational characteristic of said acknowledgement is valid and said negative response is associated with each of said tags for which said informational characteristic of said acknowledgement is invalid.

164. An EAS tag polling system as set forth in claim 163 wherein said informational characteristic is data content of said acknowledgement.

165. An EAS tag polling system as set forth in claim 163 wherein said base station is further operative to verify said data content in said acknowledgement received from each of said tags such that when verified said data content is valid and when not verified said data content is invalid.

166. An EAS tag polling system as set forth in claim 165 wherein said data content is identical for each of said tags.

167. An EAS tag polling system as set forth in claim 165 wherein said data content is different for each of said tags.

168. An EAS tag polling system as set forth in claim 165 wherein said data content for each of said tags is invariant.

169. An EAS tag polling system as set forth in claim 168 wherein said data content for each of said tags is a preselected bit string.

170. An EAS tag polling system as set forth in claim 169 wherein said informational characteristic is a bit pattern of said preselected bit string, said base station recognizing said bit pattern to verify said data content.

171. An EAS tag polling system as set forth in claim 165 wherein said data content for each of said tags is variant in accordance with a function that implements an algorithm, said base station being knowledgeable of said function to verify said data content.

172. An EAS tag polling system as set forth in claim 171 wherein said data content for each of said tags is variant as a function of time.

173. An EAS tag polling system as set forth in claim 171 wherein said data content for each one of said tags is variant as a function of a number of instances said acknowledgement is transmitted from a same one of said tags.

174. An EAS tag polling system as set forth in claim 171 wherein said data content for each of said tags is developed in accordance with said function from a seed used by said algorithm.

175. An EAS tag polling system as set forth in claim 174 wherein said seed value is stored in each of said tags.

176. An EAS tag polling system as set forth in claim 175 wherein said seed value is identical in each of said tags.

177. An EAS tag polling system as set forth in claim 175 wherein said seed value is different in each of said tags.

178. An EAS tag polling system as set forth in claim 175 wherein said seed value is an initialized bit string.

179. An EAS tag polling system as set forth in claim 175 wherein said base station is further knowledgeable of said seed value stored in each of said tags to develop expected data content with which to verify said data content in said acknowledgment received from each of said tags.

180. An EAS tag polling system as set forth in claim 179 wherein said base station is further operative to compare said expected data content to said data content in said acknowledgment received from each of said tags wherein said positive response is associated with each of said tags for which the comparison is positive and said negative response is associated with each of said tags for which the comparison is negative.

181. An EAS tag polling system as set forth in claim 174 wherein each one of said tags includes a memory in which said seed is stored, a tag clock counter to which a succession of clock pulses is applied and having a plurality of output bits at which a count of said clock pulses is developed, a logic circuit to which each of said seed and at least one of said output bits of said count are applied to develop an output bit string applied to said transmitter, said transmitter being operative to transmit said acknowledgement wherein said output bit string is said data content in said acknowledgment.

182. An EAS tag polling system as set forth in claim 181 wherein each of said tags further includes a register into which said output bit string is serially clocked and further wherein contents of said register is applied to said transmitter in response to a timing pulse.

183. An EAS tag polling system as set forth in claim 182 wherein a current value of said at least one of said output bits of said clock counter is added to the contents of said register upon said timing pulse being developed such that said data content contains said at least one of said output bits and the contents of said register.

184. An EAS tag polling system as set forth in claim 183 wherein a current value of said output bits is added to the contents of said register.

185. An EAS tag polling system as set forth in claim 182 wherein said timing pulse is developed in response to a selected one of said output bits of said clock counter transitioning from a first binary state to a second binary state.

186. An EAS tag polling system as set forth in claim 181 wherein each of said tags further includes a clock to develop said succession of clock pulses.

187. An EAS tag polling system as set forth in claim 181 wherein said base station includes a processor, a lookup table containing a seed associated with each of said tags, a clock to develop said succession of clock pulses, a base station clock counter having a plurality of output bits at which a count of said clock pulses is developed and a transmitter operative to transmit said clock pulses to each of said tags, each of said tags further including a receiver to receive said clock pulses and to apply said clock pulses to said tag clock counter, said base station clock counter developing a value at at least one of said output bits of said base station clock counter in lockstep with said at least one of said output bits of said tag clock counter, said processor developing expected data content from each of said seed in said lookup table associated with said one of said tags and said at least one of said output bits of said base station clock counter in accordance with said algorithm as implemented by said logic circuit, said processor verifying said data content in said acknowledgment received from each of said tags to said expected data content developed for each of said tags.

188. An EAS tag polling system as set forth in claim 187 wherein said processor is further operative to develop a sync pulse to reset each of said base station clock counter and said tag clock counter in each of said tags, each of said tags being responsive to said sync pulse to reset said counter.

189. An EAS tag polling system as set forth in claim 188 wherein said base station further includes a transmitter to transmit said sync pulse to each of said tags and wherein each of said tags further includes a receiver operative to receive said sync pulse and to apply said sync pulse to said counter.

190. An EAS tag polling system as set forth in claim 174 wherein each respective one of said tags includes a memory in which said seed is stored, an instance counter having a plurality of output bits at which a count of a number of instances of said acknowledgement has been transmitted from said respective one of said tags, a logic circuit to which each of said seed and said count are applied and operative to develop an output bit string, and a transmitter to which said output bit string is applied, said transmitter being operative to transmit said acknowledgement.

191. An EAS tag polling system as set forth in claim 190 wherein each of said tags further includes a register into which said output bit string is serially clocked and further wherein contents of said register is applied to said transmitter in response to a timing pulse.

192. An EAS tag polling system as set forth in claim 191 wherein said instance counter is incremented in response to said timing pulse.

193. An EAS tag polling system is set forth in claim 191 wherein each respective one of said tags further includes a clock counter to which a succession of clock pulses is applied to develop a binary count of said clock pulses, said clock counter having a selected output bit, said timing pulse being developed in response to said selected output bit transitioning from a first binary state to a second binary state.

194. An EAS tag polling system as set forth in claim 193 wherein each of said tags further includes a clock to develop said succession of clock pulses.

195. An EAS tag polling system as set forth in claim 193 wherein said base station includes a clock to develop said succession of clock pulses and a transmitter operative to transmit said clock pulses to each of said tags, each of said tags further including a receiver to receive said clock pulses and to apply said clock pulses to said clock counter.

196. An EAS tag polling system as set forth in claim 190 wherein said base station is further operative to develop a sync pulse, each of said tags being responsive to said sync pulse to reset said instance counter.

197. An EAS tag polling system as set forth in claim 196 wherein each of said tags further includes a receiver operative to receive said sync pulse and to apply said sync pulse to said instance counter.

198. An EAS tag polling system as set forth in claim 174 wherein each of said tags includes:

a n-bit wide shift register having a plurality of cascaded gates, said seed being applied as a bit string to said shift register, each of said gates having a Q output and a {overscore (Q)} output; and

a logic circuit having a plurality of inputs and an output, each of said inputs being connected to a selected one of said Q output and said {overscore (Q)} output of a corresponding one of said gates, said data content of said acknowledgement being an output bit string developed at said output.

199. An EAS tag polling system as set forth in claim 198 wherein each of said tags further includes a memory to store said seed.

200. An EAS tag polling system as set forth in claim 198 wherein said seed is transmitted to each of said tags by said base station.

201. An EAS tag polling system as set forth in claim 198 wherein a number of said inputs is less than a number of said gates.

202. An EAS tag polling system as set forth in claim 198 wherein each of said gates further has a D input, said D input being selectively connected to one of said Q output and said {overscore (Q)} output of an immediately preceding one of said gates.

203. An EAS tag polling system as set forth in claim 198 further comprising a standard gate to which said seed and an output bit of a selected one of said Q output and said {overscore (Q)} output of a least significant one of said gates are applied.

204. An EAS tag polling system as set forth in claim 198 wherein each of said tags further includes:

a buffer containing said output bit string from said output;

a counter containing a count of a selected one of clock pulses applied to said counter and each instance of said acknowledgement being transmitted from each respective one of said tags, said counter having a plurality of output bits; and

a second logic circuit operative to combine logically said output bit string in said buffer with at least one of said output bits of said counter whereby said data content for said acknowledgement for each respective one of said tags is developed.

205. An EAS tag polling system as set forth in claim 198 wherein said seed is bitwise clocked into said shift register such that each bit of said output bit string is developed as each bit of said seed is applied to said shift register.

206. An EAS tag polling system as set forth in claim 205 wherein each of said tags further includes a tag transmitter, said output bit string being bitwise applied to said transmitter.

207. An EAS tag polling system as set forth in claim 198 wherein said base station is further knowledgeable of said seed value stored in each of said tags to develop expected data content with which to verify said data content in said acknowledgment received from each of said tags.

208. An EAS tag polling system as set forth in claim 207 wherein said base station is further operative to compare said expected data content to said data content in said acknowledgment received from each of said tags wherein said positive response is associated with each of said tags for which the comparison is positive and said negative response is associated with each of said tags for which the comparison is negative.

209. An EAS tag polling system as set forth in claim 208 wherein said base station includes a receiver to receive said acknowledgement from each one of said tags and a processor operative to read said data content in said acknowledgement from each one of said tags and compare said data content to said expected data for each one of said tags.

210. An EAS tag polling system as set forth in claim 207 wherein said processor is further operative to generate contemporaneously said expected data for each one of said tags.

211. An EAS tag polling system is set forth in claim 163 wherein said request including an informational characteristic, each one of said tags being further operative to develop said informational characteristic of said acknowledgement transmitted from each respective one of said tags as a function of said informational characteristic of said request.

212. An EAS tag polling system as set forth in claim 113 wherein said request includes an identifying characteristic uniquely identifying one of said tags such that said one of said tags is operative to transmit said acknowledgment.

213. An EAS tag polling system as set forth in claim 212 wherein said base station is further operative to transmit said request for each respective one of said tags as a succession.

214. An EAS tag polling system as set forth in claim 213 wherein said base station is operative to transmit each request in response to receipt of said acknowledgment transmitted from one of said tags in response to an immediately prior request in said succession.

215. An EAS tag polling system as set forth in claim 214 wherein said base station is further operative to transmit said request upon expiration of the selected time duration in the event said acknowledgment from one of said tags is not received in response to said immediately prior request.

216. An EAS tag polling system as set forth in claim 214 wherein said base station is further operative to resend said request to one of said tags upon expiration of a selective time duration in the event said acknowledgment from said one of said tags is not received.

217. An EAS tag polling system as set forth in claim 113 wherein each of said tags is operative to reflect said request therefrom, said reflected request being said acknowledgment transmitted from each respective one of said tags.