System and method for radio frequency tag group select
First Claim
1. A systems for selecting a subset of slaves that satisfy a selection criterion and then insulating the selected subset from further participation in a selection and insulating process, said system comprising:
- a master unit for communicating a selection criterion command to a plurality of slaves, the selection criterion command representing the selection criterion;
each slave of said plurality of slaves being in one of three or more different possible states during the selection and insulating process;
a memory in said each slave containing at least one information value for use in evaluation of a selection criterion;
a receiving unit in said each slave for receiving the selection criterion command from the master unit;
a processing unit in said each slave that processes the selection criterion command by moving the slave from a first state to a second state if and only if the slave is already in the first state and the at least one information value satisfies the selection criterion;
whereby said each slave is deemed to be selected if said each slave is in the second state after the processing unit in said each slave has processed the selection criterion command; and
moving slaves in the second state to a third state so as to be unaffected by further selection criterion commands.
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Accused Products
Abstract
A master entity is capable of broadcasting commands to a plurality of three-state-selection machine slaves. Transitions from one state to another are effected on instruction from commands in a sequence of commands broadcast from the master. Slaves move to another state when they satisfy a primitive condition specified in the command. By moving slaves among the three sets, a desired subset of slaves can be isolated in one of the sets. This desired subset of slaves then can be moved to one of the states that is unaffected by commands that cause the selection of other desirable subsets of slaves. In the embodiments of the incorporated U.S. Pat. No. 5,673,037, certain subgroups of radio frequency (RF) tags are selected for querying, communicating, and/or identifying by commands from a base station. Commands from the base station may cause the tags to change state which either prevents or allows a given tag to participate in an identification process. In this way, a given subgroup(s) of tags meeting certain criteria can be selected for querying, communicating, and/or identifying.
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Citations
6 Claims
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1. A systems for selecting a subset of slaves that satisfy a selection criterion and then insulating the selected subset from further participation in a selection and insulating process, said system comprising:
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a master unit for communicating a selection criterion command to a plurality of slaves, the selection criterion command representing the selection criterion;
each slave of said plurality of slaves being in one of three or more different possible states during the selection and insulating process;
a memory in said each slave containing at least one information value for use in evaluation of a selection criterion;
a receiving unit in said each slave for receiving the selection criterion command from the master unit;
a processing unit in said each slave that processes the selection criterion command by moving the slave from a first state to a second state if and only if the slave is already in the first state and the at least one information value satisfies the selection criterion;
whereby said each slave is deemed to be selected if said each slave is in the second state after the processing unit in said each slave has processed the selection criterion command; and
moving slaves in the second state to a third state so as to be unaffected by further selection criterion commands. - View Dependent Claims (2)
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3. A method for selecting a subset of slaves that satisfy a selection criterion and then causing the selected subset of slaves to be insulated from further participation in a selecting and insulating process, said method comprising;
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storing at least one information value in each of a plurality of slaves for use an evaluating a selection criterion;
representing a selection criterion as a selection criterion command;
communicating the selection criterion command to the plurality of slaves, each slave of said plurality of slaves being in one of three or more difference states during the selecting and insulating process;
processing the selection criterion command at said each slave by moving said each slave from a first state to a second state if and only if the slave is already in the first state and the at least one information value satisfies the selection criterion;
thendeeming said each slave in the second state to be selected; and
moving the slaves in the second state to a third state so as to be unaffected by further selection criterion commands. - View Dependent Claims (4)
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5. A state machine slave for responding to a selection criterion command from a master unit, and when selected being insulated from further participation in a selection and insulating process, said state machine slave comprising;
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first, second and third states;
a memory containing at least one information value for evaluating a selection criterion;
a receiving unit for receiving a selection criterion command representing a selection criterion;
a processing unit that process the selection criterion command by moving the slave from a first state to a second state if and only if the slave is already in the first state and the at least one information value satisfies the selection criterion;
whereby the slave is deemed to be selected if the slave is in the second state after the processing unit has processed the selection criterion command; and
the slave being movable from the second state to the third state so as to be unaffected by further selection criterion commands. - View Dependent Claims (6)
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Specification