Repeater amplifier with signal firewall protection for power line carrier communication networks

• US 7,007,305 B2
• Filed: 09/06/2001
• Issued: 02/28/2006
• Est. Priority Date: 09/06/2001
• Status: Expired due to Term

• Current Assignee: Signify North America Corporation (Signify N.V.)
• Original Assignee: Genlyte Thomas Group LLC (Signify N.V.)
• Inventors: Carson, Steven R., Griffin, Raymond T.
• Primary Examiner(s): JUNG, DAVID YIUK
• Application Number:
  US09/947,964
• Publication Number:
  US 20030043027A1
• Time in Patent Office: 1,636 Days
• Field of Search: 34031001-31006, 34087018-87027, 700/286, 700/292, 700/293, 700/295, 700/297, 700/298, 713200-340, 375/130, 375/211, 726 1- 36
• US Class Current: 726/36
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals

Abstract

A repeater amplifier boosts weak control signals on a PLC network, with noise discrimination and signal firewall protection. The AC supply voltage is filtered by a high frequency blocking filter to block external noise signals. Operating power for network signaling devices and the repeater amplifier is derived from the clean AC supply voltage. Noise discrimination and signal firewall protection are provided by amplifying and repeating only those receiver pulse signals that (a) have an analog amplitude that exceeds a predetermined analog threshold value, (b) occur during intervals that control data signal modulation is being applied to the filtered AC supply voltage and (c) occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier (PLC) modulation frequency.

Claims

1. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter coupled to the power distribution conductor for modulating the AC supply voltage with control data signals at a power line carrier modulation frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a blocking filter including an input terminal for receiving AC supply voltage from an AC power source and an output terminal for delivering filtered AC supply voltage to a power distribution conductor while substantially attenuating the passage of high frequency signals between the input and output terminals of the blocking filter, the blocking filter including a filter circuit that provides low signal attenuation from DC through the power distribution frequency of the AC supply voltage up to a cutoff frequency, and provides high signal attenuation above the cutoff frequency; and

a signal repeater circuit connectable to the power distribution conductor on the output of the blocking filter for recovering control data signals from modulated AC supply voltage and repeating the control data signals at an amplified voltage level on the power distribution conductor.

2. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 1, further comprising:

a signal discrimination circuit coupled to the signal repeater circuit for selectively enabling operation of the signal repeater circuit in response to the recovery of control data signals that have an amplitude exceeding a predetermined threshold value.

3. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 1, further comprising:

a signal discrimination circuit coupled to the signal repeater circuit for selectively enabling operation of the signal repeater circuit in response to the recovery of control data signals occurring at a frequency within a predetermined frequency band centered on the transmitted power line carrier modulation frequency.

4. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 1, further comprising:

a signal discrimination circuit coupled to the signal repeater circuit for selectively enabling operation of the signal repeater circuit in response to the recovery of control data signals occurring during intervals that power line carrier modulation is being applied to the AC supply voltage.

5. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 1, wherein the signal repeater circuit comprises:

a receiver coupled to the power distribution conductor for recovering control data signals from the modulated AC supply voltage;

an amplifier coupled to the power distribution conductor for generating an analog control signal that is proportional to the amplitude of the modulated AC supply voltage;

a transmitter for amplifying control data signals and modulating the AC supply voltage with the amplified control data signals; and

a signal discrimination circuit coupled to the receiver and to the signal amplifier for inputting recovered control data signals to the transmitter and selectively enabling the transmitter to repeat the recovered control data signals at an amplified voltage level in response to the recovery of control data signals that satisfy one or more of the following conditions;

(a) have an analog amplitude exceeding a predetermined threshold value, or (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage, or (c) occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier modulation frequency.

6. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier modulation frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a high frequency blocking filter including a power input terminal for receiving AC supply voltage from an AC power source and a power output terminal for delivering filtered AC supply voltage to a power distribution conductor while blocking or substantially attenuating the passage of high frequency signals between the input and output terminals of the blocking filter;

a repeater connectable to the power distribution conductor on the output side of the high frequency blocking filter for recovering control data signals from modulated AC supply voltage and repeating the control data signals at an amplified voltage level on the power distribution conductor; and

a signal discrimination circuit coupled to the repeater for selectively enabling the repeater to transmit the amplified control data signals in response to the recovery of control data signals that satisfy each of the following conditions;

(a) have an analog amplitude that exceeds a predetermined analog threshold value, and (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage, and (c) occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier modulation frequency.

7. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a high frequency blocking filter including a power input terminal for receiving AC supply voltage from an AC power source and a power output terminal for delivering filtered AC supply voltage to a power distribution conductor while blocking or substantially attenuating the passage of high frequency signals between the input and output terminals of the blocking filter;

a repeater connectable to the power distribution conductor on the output side of the high frequency blocking filter for recovering control data signals from modulated AC supply voltage and transmitting amplified control data signals on the power distribution conductor substantially in synchronous relation with the recovered control data signals; and

a signal discrimination circuit coupled to the repeater for enabling the repeater to transmit amplified control data signals in response to the recovery of control data signals that satisfy one or more the following conditions;

(a) have an analog amplitude that exceeds a predetermined analog threshold value, or (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage, or (c) occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier modulation frequency.

8. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the recovered control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a high frequency blocking filter including a power input terminal for receiving AC supply voltage from an AC power source and a power output terminal for delivering filtered AC supply voltage to a power distribution conductor while blocking or substantially attenuating the passage of high frequency signals between the input terminal and output terminal of the blocking filter;

a repeater connectable to the power distribution conductor on the output side of the high frequency blocking filter for recovering control data signals from modulated AC supply voltage and transmitting the control data signals at an amplified voltage level on the power distribution conductor; and

a signal discrimination circuit coupled to the repeater for selectively enabling operation of the repeater in response to the recovery of control data signals that (a) have an analog amplitude that exceeds a predetermined analog threshold value, and (b) occur at a frequency lying in a predetermined frequency band centered on the transmitted power line carrier communication frequency.

9. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a high frequency blocking filter including a power input terminal for receiving AC supply voltage from an AC power source and a power output terminal for delivering filtered AC supply voltage to a power distribution conductor while blocking or substantially attenuating the passage of high frequency signals between the input and output terminals of the blocking filter;

a signal repeater connectable to the power distribution conductor on the output side of the high frequency blocking filter for recovering control data signals from modulated AC supply voltage and transmitting the control data signals at an amplified voltage level on the power distribution conductor; and

a signal discrimination circuit coupled to the repeater for selectively enabling operation of the repeater in response to the recovery of control data signals that (a) occur during intervals that power line carrier modulation is being applied to the AC supply voltage, and (b) occur at a frequency within a predetermined frequency band centered on the applied power line carrier modulation frequency.

10. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier modulation frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a high frequency blocking filter including a power input terminal for receiving AC supply voltage from an AC power source and a power output terminal for delivering filtered AC supply voltage to a power distribution conductor while blocking or substantially attenuating the passage of high frequency signals between the input and output terminals of the blocking filter;

a signal repeater connectable to the power distribution conductor on the output side of the high frequency blocking filter for recovering control data signals from modulated AC supply voltage and transmitting the control data signals at an amplified voltage level on the power distribution conductor; and

a signal discrimination circuit coupled to the repeater for selectively enabling operation of the repeater in response to the recovery of control data signals that (a) have an analog amplitude that exceeds a predetermined analog threshold value, and (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage.

11. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the recovered control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a bidirectional signal coupling circuit having an input for receiving AC supply voltage from an AC power source and an output for delivering AC supply voltage to a power distribution conductor;

a modulation decoder circuit coupled to the output of the bidirectional signal coupling circuit for recovering high-frequency modulation data from the AC supply voltage;

a signal amplifier coupled to the output of the signal coupling circuit for generating an analog control signal proportional to the amplitude of the AC supply voltage;

a comparison circuit coupled to the signal amplifier for producing a transmit enable signal that has a logic high value when the amplitude of the analog control signal exceeds a pre-determined threshold value and has a logic zero value when the amplitude is less than the pre-determined threshold value;

a gate-actuated switch coupled to the output of the bidirectional coupling circuit, the switch having switched and unswitched terminals for connecting and removing bias clamping voltage to and from the output of the bidirectional coupling circuit, and having a gate terminal for turning the switch ON and OFF in response to binary logic signals;

a clamping circuit coupled to the output of the bidirectional coupling circuit for clamping the coupling circuit output at a first voltage level when the gate-actuated switch is in the OFF condition, and clamping the coupling circuit output at a second voltage level when the gate-actuated switch is in the ON condition; and

a signal discrimination circuit having a first input connected to the comparison circuit for receiving the transmit enable signal, a second input connected to the output of the modulation decoder for receiving the binary modulation data, and an output coupled to the gate of the gate-actuated switch, wherein the gate-actuated switch is gated ON and OFF in response to the binary modulation data.

12. Control apparatus for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage to one or more loads, a transmitter coupled to the power distribution conductor for modulating the AC supply voltage with control data signals at a power line carrier modulation frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, the control apparatus comprising, in combination:

a high frequency blocking filter including a power input circuit for receiving AC supply voltage from an AC power source and a power output circuit for delivering filtered AC supply voltage to a power distribution conductor while blocking or substantially attenuating the passage of high frequency signals between the input and output terminals of the blocking filter;

a bidirectional signal transmission circuit having a first signal port coupled to the power distribution conductor and having a second signal port;

a signal repeater connected to the second signal port for recovering control data signals from modulated AC supply voltage and repeating the control data signals at an amplified voltage level on the power distribution conductor; and

a signal discrimination circuit coupled to the signal repeater for selectively enabling operation of the repeater in response to the recovery of control data signals that satisfy one or more of the following conditions;

(a) have an analog amplitude exceeding a predetermined threshold value, or (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage, or (c) occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier modulation frequency.

13. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network of the type including a power distribution conductor for distributing AC supply voltage at a power distribution frequency to one or more loads, a transmitter for periodically modulating the AC supply voltage with a burst of control data signals at a power line carrier modulation frequency, and a receiver coupled to the power distribution conductor for recovering the control data signals and using the control data signals to apply AC power to one or more of the loads, comprising the steps:

filtering the AC voltage that is supplied to the power distribution conductor by blocking or substantially attenuating the passage of signals that occur at a frequency higher than the power distribution frequency;

modulating the filtered AC supply voltage with a burst of control data signals at a power line carrier modulation frequency during a first command cycle;

recovering the control data signals from the modulated AC voltage;

amplifying the recovered control data signals; and

modulating the filtered AC supply voltage with the amplified control data signals during a second command cycle.

14. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that have an amplitude exceeding a predetermined analog threshold value.

15. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that occur at a frequency within a predetermined frequency band centered on the transmitted power line carrier modulation frequency.

16. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that occur during intervals that power line carrier modulation is being applied to the filtered AC supply voltage.

17. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that (a) have an analog amplitude that exceeds a predetermined analog threshold value, and (b) occur at a frequency lying in a predetermined frequency band centered on the transmitted power line carrier communication frequency.

18. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that (a) occur during intervals that power line carrier modulation is being applied to the AC supply voltage, and (b) occur at a frequency lying in a predetermined frequency band centered on the transmitted power line carrier communication frequency.

19. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that (a) have an amplitude exceeding a predetermined analog threshold value;

and (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage.

20. A method for improving the reliability of two-way communication between two or more signaling devices in a power line carrier communication network as set forth in claim 13, wherein the amplified control data modulation step is selectively performed in response to the recovery of control data signals that (a) have an amplitude exceeding a predetermined analog threshold value;

and (b) occur during intervals that power line carrier modulation is being applied to the AC supply voltage; and

(c) occur at a frequency lying in a predetermined frequency band centered on the transmitted power line carrier communication frequency.