REMOTE METER READING SYSTEM USING ELECTRIC POWER LINES

• US 3,815,119 A
• Filed: 03/01/1972
• Issued: 06/04/1974
• Est. Priority Date: 03/01/1972
• Status: Expired due to Term

• Current Assignee: Alexander Finlay Jr, Robert E. Dyer, William D. Kessler
• Original Assignee: Alexander Finlay Jr, Robert E. Dyer, William D. Kessler
• Inventors: Dyer, Robert E., Finlay, Alexander Jr., Kessler, William D.
• Primary Examiner(s): Habecker, Thomas B.
• Application Number:
  US05/230,873
• Time in Patent Office: 825 Days
• Field of Search: 340/27P,205,31A,310,184,31R
• US Class Current: 340/870.03
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

A remote meter reading system in which transmitters provide data signals over electric power line conductors to indicate the measurements of each of a plurality of meters to associated receivers at a remote location. The meter transmitters are divided into groups, the transmitters of each group being operative to generate different frequency signals in a given frequency band assigned to such group. The transmitters of each group are further divided into subgroups, each subgroup of transmitters being connected to a correspondingly different pair of the power line conductors. A receiver unit is provided for each subgroup of transmitters, the receiver for a subgroup being tunable to the frequencies in the band assigned to the group, and being connected to the same pair of line conductors as the transmitters of its associated subgroup. Each transmitter provides signals at a preassigned frequency as determined by the group and subgroup to which the transmitter is assigned, the signals being of a first and second phase to represent the meter measurement by logic 1 and logic O signals. The signal input to each receiver is sampled for phase and converted to digital signals which are stored in discrete storage circuits for each of the transmitters.

Claims

1. An automatic system for reading measurements for meter devices over a plurality of transmission lines of an electric power distribution system comprising:

groups of meter transmitter circuits, each group having a different assigned frequency band, and each meter transmitter circuit having means generating signals at a different frequency within the frequency band assigned to its group for representing the measurements of one associated meter device, means connecting the signals of the signal generator means of each group only to a different pair of the transmission lines for providing subgroups of the signal generator means, groups of receivers, means in each receiver tuning each receiver in each group for receiving the signals in a different one of the assigned frequency bands, and means connecting a receiver in each group to the different pairs of the transmission lines as subgroups of the receivers in each receiver group for receiving only the signals of a subgroup of transmitters connected to the same transmission line pair.

2. A system as set forth in claim 1 in which said signal generator means in each of said meter transmitter circuits includes means connecting said signal generating means to the same transmission line pair to which said generated signal of said signal generator means is connected for providing power to said signal generator means.

3. A system as set forth in claim 1 in which said signal generator means in a first group includes means for providing frequency output signals in a first band, and said signal generator means in a second group includes means for providing frequency output signals in a second band, and in which each group of signal generator means is divided into three subgroups, one of said subgroups including means connecting the signal generator means of said one subgroup to a first and second one of said transmission lines, a second subgroup including means for connecting the signal generator means of the second subgroup to a first and third ones of said transmission lines, and a third subgroup including means for connecting the signal generator means of the third subgroup to the second and third ones of said transmission lines.

4. A system as set forth in claim 1 in which each receiver of a group additionally comprises means tuning said receiver for sequentially receiving said different frequency signals in one of said frequency bands.

5. A system as set forth in claim 1 in which said transmission lines comprise three conductors L1, Ln, and L2;

and in which one group of receivers includes means tuned to receive signals in one frequency band, and a second group of receivers includes means tuned to receive signals in a second frequency band, and in which said means connecting said receivers to said transmission line include means connecting subgroups of one receiver in each group to the conductor pair L1, Ln, means connecting second subgroups of one receiver in each group to the conductor pair L1, L2, and means connecting third subgroups of one receiver in each group to the conductor pair L2, Ln.

6. A system as set forth in claim 5 which includes program means sequentially tuning the receiver in each subgroup to each of the signal frequencies generated by the signal generating means connected to the same transmission line pair as the receiver for receiviNg the signals of each signal generator means in one subgroup of transmitter circuits.

7. A system as set forth in claim 6 in which said receiver tuning means comprise superheterodyne receiver tuning means haivng oscillator means for providing a beat IF signal output, and means adjusting said oscillator means for providing the same frequency IF signal for each of the different frequency signals to which said receiver is tuned.

8. A system as set forth in claim 6 wherein said signal generating means additionally comprise means phase encoding said generated signals for representing said meter measurements and in which each said receiver includes means for detecting said phase of said signals received thereby, means for providing signals over discrete output paths for each different phase signal detected, and means connected to said paths and responsive to said sequential receiver tuning means for providing a separate count of the signals output over each of said paths for each of said transmitter circuits to which said receiver is tuned.

9. A system as set forth in claim 1 in which each of said signal generating means additionally comprise means phase encoding said generated signals for representing said meter measurements and said receivers include means tuning said receivers to receive each of said different frequencies in said bands transmitted by one said subgroup of transmitter circuits, means for detecting said phase of said transmitted signals and for providing output signals indicative said detected phase, means for separately storing said output signals, means for selectively extending said output signals to said separate storage means, and means for selectively enabling said tuning means to receive said signal generator means signals of different ones of said transmitter circuits and simultaneously controlling said selectively extending means to extend said signal output of said phase detector means to a one of said storage means assigned to said transmitter circuit from which said receiver received said signal generator means signals.

10. A system as set forth in claim 1 which includes means connected to said receiver for accumulating the measurements represented by said signals received by said receiver, and a signal processing means for providing data words which represent the accumulated measurements of each meter and the identity of each meter.

11. A system as set forth in claim 1 in which said signal generator means includes an encoder switch and means operatively connecting said switch and said associated meter device for operating said switch in correspondence to measurements of said associated meter device and in which said signal generator means further includes an oscillator circuit for generating said signal generator signals and an enabling circuit responsive to said switch for enabling oscillator generation of said signals of a first phase to represent one set of measurements of said associated meter device and of a second phase to represent a second set of measurements of said associated meter device, and in which said means for connecting the signal output of each signal generator means to its assigned pair of said transmission lines includes a series resonant circuit.