Signalling system and a transponder for use in the system

• US 20020106988A1
• Filed: 02/04/2002
• Published: 08/08/2002
• Est. Priority Date: 02/06/2001
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Marsden, Ian A., Davie, Alan J.
• Granted Patent: US 6,925,287 B2
• Time in Patent Office: Days
• US Class Current: 455/39
• CPC Class Codes: G01D 9/005 Solid-state data loggers
• CPC Class Codes: G06K 19/0705 the battery being connected to a power saving arrangement
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs

Abstract

A signalling system includes a plurality of active transponders (10), an interrogation station (12) and a source (14) of switching signals. Each of the transponders has a microcontroller (20), a radio transceiver (34) for responding to radio interrogation signals from the interrogation station, the radio transceiver being coupled to the controller by way of switching means (36) which switches the transceiver on or off whilst leaving the microcontroller active, and a passive receiver (38) for receiving switching signals from the source of switching signals which signals are used by the microcontroller for switching-on or -off the transceiver. Transducers (26, 28, 30) may be coupled to the microcontroller for monitoring environmental features, such as ambient temperature and humidity, and data relating to the features is stored in a RAM (32) in readiness to be relayed to storage means (56) in the interrogation station (12) as and when required. Signals received by the passive receiver enable the radio transceiver to be de-activated in locations, such as in an aircraft, where spurious radiation from the transponder is not permitted and to be re-activated when removed from such a location.

Claims

1. A signalling system comprising a transponder including a controller for controlling the operation of the transponder, a radio transceiver coupled to the controller by way of switching means, an electric current source coupled to the controller, and a radio signal receiving means coupled to the controller for providing signals for activating the switching means to inhibit or permit the operation of the radio transceiver, a transponder interrogation station for interrogating the transponder by way of signals transmitted to, and received from, the radio transceiver, and a source of switching signals receivable by the signal receiving means when in range.

2. A system as claimed in claim 1, characterised in that the transponder further comprises at least one transducer coupled to the controller and a random access memory for storing data representative of information produced by the transponder.

3. A system as claimed in claim 2, characterised in that the transponder interrogation station has storage means for storing said data relayed by the transponder in response to an interrogation signal.

4. A system as claimed in claim 1, 2 or 3, characterised in that the radio receiving means comprises a passive radio receiver and in that the source of switching signals comprises a radio transmitter for communicating with the passive radio receiver.

5. A system as claimed in any one of claims 1 to 3, characterised in that the transponder interrogation station and the source of switching signals operate at different frequencies.

6. A system as claimed in claim 4, characterised in that the transponder interrogation station and the source of switching signals operate at different frequencies.

7. A transponder for use in an interrogation system, the transponder including a controller for controlling the operation of the transponder, a radio transceiver coupled to the controller by way of switching means, an electric current source coupled to the controller, and a radio signal receiving means coupled to the controller for providing signals for activating the switching means to inhibit or permit the operation of the radio transceiver.

8. A transponder as claimed in claim 7, characterised in that the transponder further comprises at least one transducer coupled to the controller and a random access memory for storing data representative of information produced by the transponder.

9. A transponder as claimed in claim 8, characterised in that the transponder interrogation station has storage means for storing said data relayed by the transponder in response to an interrogation signal.

10. A transponder as claim 7, 8 or 9, characterised in that the radio receiving means comprises a passive radio receiver.