RF meter reading system

• US 5,451,938 A
• Filed: 10/22/1993
• Issued: 09/19/1995
• Est. Priority Date: 10/22/1993
• Status: Expired due to Term

• Current Assignee: Neptune Technology Group Incorporated (Roper Technologies, Inc.)
• Original Assignee: Schlumberger Industries Incorporated (Schlumberger NV)
• Inventors: Brennan, William J. Jr.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Wu, Daniel J.
• Application Number:
  US08/141,840
• Time in Patent Office: 697 Days
• Field of Search: 340/870.02, 340/870.03, 340/825.54, 340/870.14, 340/870.18, 340/870.19, 375/117, 375/87, 375/282, 375/284, 375/293, 375/369, 370/48, 358/438, 358/409, 358/413
• US Class Current: 340/870.14
• CPC Class Codes: G01D 4/006 Remote reading of utility meters to a non-fixed location, i.e. mobile location
• CPC Class Codes: G08C 15/00 Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

The RF meter reading system includes a transmitter having an encoder. Meter data is encoded and modulated using a bi-phase modulating scheme. In order to uniquely identify the start of a data transmission, a super start field, which is an "illegal" bi-phase signal is used. The super start field is selected such that it cannot be recognized if transmissions from more than one transmitter are being received by the receiver.

Claims

1. A radio-frequency meter reading system, comprising:

(a) a radio-frequency transmitter;

(b) encoder means associated with said radio-frequency transmitter for collecting data from a meter; and

(c) a bi-phase modulator means for modulating the data from said encoder means into an information signal which is transmitted by said radio-frequency transmitter, said information signal representing a first logical value of said data with a first logical level signal and a second logical value of said data with a second logical level signal and said information signal including a synch signal, a start signal, a message signal, and a verification signal;

wherein said start signal comprises a signal which contains neither said first logical level signal nor said second logical level signal.

2. The radio-frequency meter reading system of claim 1, further comprising:

(a) a radio-frequency receiver containing means for receiving said information signal from said radio-frequency transmitter;

(b) means for decoding said information signal into said data;

(c) means for identifying said start signal; and

(d) means for verifying receipt of valid data from said radio-frequency transmitter.

3. The radio-frequency reading system as set forth in claim 1, wherein said encoding means comprises a microprocessor.

4. The radio-frequency reading system as set forth in claim 1, wherein said first logical level signal has a first frequency, said second logical level signal has a second frequency, and said start signal is at a fixed value.

5. The radio-frequency reading system as set forth in claim 1, wherein said information signal is emitted at periodic intervals.

6. The radio-frequency reading system as set forth in claim 5, wherein said periodic intervals are at irregular intervals.

7. The radio-frequency reading system as set forth in claim 1, wherein said radio-frequency transmitter is battery powered.

8. The radio-frequency reading system as set forth in claim 2, wherein said verifying means performs a cyclic redundancy check on said data.

9. A radio-frequency receiver for receiving an information signal from each of a plurality of radio-frequency transmitters, comprising:

(a) an antenna for detecting said information signal from each of said radio-frequency transmitters;

(b) means for receiving said information signal and for synchronizing a decoding unit to a frequency of a synch signal contained within said information signal;

(c) means for identifying a start signal within said information signal; and

(d) said decoding unit for decoding said information signal into data;

said information signal representing a first logical value of said data as a first logical level signal and a second logical value of said data as a second logical level signal;

wherein said decoding unit determines that said information signal is from only one of said radio-frequency transmitters when said start signal is received without having either said first logical level signal or said second logical level signal.

10. The radio-frequency receiver as set forth in claim 9, wherein each of said radio-frequency transmitters are associated with a respective utility meter and said data decoded from said information signal indicates a reading of said utility meter.

11. The radio-frequency receiver as set forth in claim 9, wherein said decoding unit comprises a microprocessor.

12. The radio-frequency receiver as set forth in claim 9, further comprising means for receiving a verification signal and for verifying that said data is valid data based upon said verification signal.

13. The radio-frequency receiver as set forth in claim 9, further comprising a memory for storing said data from each of said radio-frequency transmitters.

14. The radio-frequency receiver as set forth in claim 9, wherein said receiving means automatically adjusts a gain of said information signal.

15. A radio-frequency meter transmitting apparatus, comprising:

(a) a radio-frequency transmitting antenna;

(b) encoder means associated with said radio-frequency transmitting antenna for collecting data from a meter; and

(c) a bi-phase modulator means for modulating the data from said encoder means into an information signal which is transmitted from said radio-frequency transmitting antenna, said information signal representing a first logical value of said data with a first logical level signal and a second logical value of said data with a second logical level signal and said information signal including a synch signal, a start signal, a message signal, and a verification signal;

wherein said start signal comprises a signal which contains neither said first logical level signal nor said second logical level signal.