Tag evaluation module for radio frequency identification (RFID) systems

• US 6,346,881 B1
• Filed: 03/01/2000
• Issued: 02/12/2002
• Est. Priority Date: 03/01/2000
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: Samsys Technologies Incorporated
• Inventors: Davidson, William E.
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US09/516,117
• Time in Patent Office: 713 Days
• Field of Search: 340/933, 340/928, 340/901-905, 340/934, 340/936, 340/941, 340/991, 340/815.54, 340/825.54, 340/825.49, 340/514, 340/572.1
• US Class Current: 340/514
• CPC Class Codes: G06K 7/00 Methods or arrangements for sensing record carriers, e.g. for reading patterns methods or arrangements for marking the record carrier in digital fashion G06K1/00; pattern recognition G06F18/00; arrangements for image or video recognition or understanding G06V10/00; character recognition, recognising digital ink or document-oriented image-based pattern recognition G06V30/00
• CPC Class Codes: G06K 7/0095 Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly testing of electrical circuits G01R31/28
• CPC Class Codes: G06K 7/10465 the interrogation device being capable of self-diagnosis, e.g. in addition to or as part of the actual interrogation process testing of electrical circuits in general G01R31/28

Abstract

Apparatus and method of evaluating and installing a wireless system, and is suited for a radio frequency identification (RFID) system. The apparatus determines the suitability of a particular site for use with specific RFID tag types. The apparatus comprises a tag evaluation module having a drobe, a wireless transmitter, and a processor. The probe is coupled to a tag under evaluation and information, such as tag power and data, is collected and stored by the processor. The information may be processed into logs which are transmitted to a computer for further processing. The tag evaluation apparatus may be utilized as a site survey tool before installation of a RFID system, or after installation as a diagnostic or performance optimizing tool.

Claims

1. An apparatus for evaluating a radio frequency identification system having a plurality of tags, said tags operating at a selected frequency, and said tags being responsive to an output signal transmitted by an interrogator and each of said tags including a circuit for receiving the output signal transmitted by the interrogator and transmitting a return signal in response to said output signal, said apparatus comprising:

(a) a probe for coupling to the circuit in one of said tags, and said probe including a plurality of lines for sampling selected signals in said circuit;

(b) a controller coupled to said probe and including a processor for processing said sampled signals and memory for storing information associated with said sampled signals; and

(c) a transmitter coupled to said controller and responsive to control signals from said controller for transmitting said stored information to a remote device, wherein said transmitter utilizes a communication channel operating at a different frequency than the selected frequency for the tags.

2. The apparatus as claimed in claim 1, wherein said communication channel comprises a radio frequency channel.

3. The apparatus as claimed in claim 1, wherein one of said sampled signals comprises a power reading for said tag.

4. The apparatus as claimed in claim 3, wherein one of said sampled signals comprises a data signal from said tag.

5. The apparatus as claimed in claim 4, wherein one of said sampled signals comprises a gap reading for the tag.

6. The apparatus as claimed in claim 2, Wherein said processor includes means for staring a plurality of said power readings and means for generating a power reading log, said power reading log being adapted for transmission to said remote device.

7. The apparatus as claimed in claim 4, wherein said processor includes means for storing a plurality of said data signals and means for generating a data log, said data log being adapted for transmission to said remote device.

8. The apparatus as claimed in claim 6, wherein said remote device comprises a computer, said computer having a communication link coupled to said interrogator and including means for comparing said power readings for said tag with power readings from said interrogator.

9. The apparatus as claimed in claim 7, wherein said remote device comprises a computer, said computer having a communication link to said interrogator and including means for comparing said data signals for said tag with data signals obtained from said interrogator.

10. The apparatus as claimed in claim 1, wherein said apparatus comprises a portable device powered by a battery supply.

11. An apparatus for evaluating a wireless system having a plurality of wireless terminals, said wireless terminals operating at a selected frequency, and said wireless terminals being responsive to an output signal transmitted by a transceiver terminal and each of said wireless terminals including a circuit for receiving the output signal transmitted by the transceiver terminal and transmitting a return signal in response to said output signal, said apparatus comprising:

(a) a probe for coupling to the circuit in one of said wireless terminals, and said probe including a plurality of lines for sampling selected signals in said circuit;

(b) a controller coupled to said probe and including a processor for processing said sampled signals and memory for storing information associated with said sampled signals; and

(c) a transmitter coupled to said controller and responsive to control signals from said controller for transmitting said stored information to a remote device, wherein said transmitter utilizes a communication channel operating at a different frequency than the selected frequency for the wireless terminal.

12. The apparatus as claimed in claim 11, wherein said communication channel comprises a radio frequency channel.

13. A data signal embodied in a carrier wave, said data signal providing information from a tag under evaluation in a radio frequency identification system to a remote device, said radio frequency identification system including a plurality of tags operating at a selected frequency, and said tags being responsive to an output signal transmitted by an interrogator, said data signal comprising:

(a) an envelope;

(b) a data portion, said portion providing information about said tag under evaluation;

(c) wherein said carrier wave has a frequency different than the selected frequency of said tag under evaluation; and

(d) said data portion including information related to a power level residing in said tag under evaluation.

14. The data signal as claimed in claim 13, wherein said data portion includes information related to data transmitted to said interrogator by said tag under evaluation.

15. The data signal as claimed in claim 13, wherein said data portion includes a log of power level readings obtained from said tag under evaluation.

16. The data signal as claimed in claim 13, wherein said data portion includes a log of data signals transmitted by said tag to said interrogator.

17. The data signal as claimed in claim 13, wherein said data portion includes information related to data transmitted by said interrogator to said tag under evaluation.

18. The data signal as claimed in claim 13, wherein said data portion includes a log of data signals received by said tag from said interrogator.