Two-wire dc communication system and transceiver
First Claim
1. A dc signaling transceiver for communicating over a single pair of conductors which carry a dc communications voltage at a level Vcomm ;
- comprising(a) microprocessor means having a signal input terminal Vin, a signal output terminal Vout, a sensor input circuit coupled to a sensor transducer, and a control output circuit coupled to control an external device;
(b) voltage limiting means having an input coupled to said pair of conductors to receive said dc communications voltage level Vcomm and an output coupled to said microprocessor means to supply thereto a supply voltage Vdd at a predetermined level less than said communications voltage level Vcomm ; and
(c) signal input/output means coupled to said pair of conductors and to said microprocessor means signal input terminal and signal output terminal, including means for applying incoming pulse signals from said conductors to said input terminal, and means for applying onto said conductors output pulse signals that have high and low values at said dc communications voltage level Vcomm and a predetermined voltage level VZ2 that is between said communications voltage Vcomm and said supply voltage Vdd.
1 Assignment
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Accused Products
Abstract
Arrangement for dc signaling between a transmitter or transceiver over a single pair of conductors to another transceiver or receiver of similar design. The conductors carry a dc communications voltage at a level Vcomm (e.g., 24 to 35 volts dc) and power for the tranceivers, receivers and/or transmitters of the system. The transceiver comprises a microprocessor having a signal input terminal Vin, a signal output terminal Vout, a sensor input circuit coupled to a sensor transducer, e.g., a temperature sensor, and a control output circuit coupled to control an external device, e.g., a furnace relay. A voltage limiting circuit device coupled to the pair of conductors supplies the microprocessor with a supply voltage Vdd at a predetermined level (e.g., 5 volts dc) less than the communications voltage level Vcomm. A signal input/output circuit coupled to the pair of conductors and to the microprocessor signal input and output terminals applies incoming pulse signals from the conductors to the input terminal, and applies onto the dc conductors output pulse signals. The output signals have high and low values respectively at the dc communications voltage level Vcomm and a predetermined voltage level VZ2 (e.g., 10 to 12 volts) between the communications voltage Vcomm and the supply voltage Vdd. The signal input/output circuit can comprise a zener and a transistor.
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Citations
17 Claims
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1. A dc signaling transceiver for communicating over a single pair of conductors which carry a dc communications voltage at a level Vcomm ;
- comprising
(a) microprocessor means having a signal input terminal Vin, a signal output terminal Vout, a sensor input circuit coupled to a sensor transducer, and a control output circuit coupled to control an external device; (b) voltage limiting means having an input coupled to said pair of conductors to receive said dc communications voltage level Vcomm and an output coupled to said microprocessor means to supply thereto a supply voltage Vdd at a predetermined level less than said communications voltage level Vcomm ; and (c) signal input/output means coupled to said pair of conductors and to said microprocessor means signal input terminal and signal output terminal, including means for applying incoming pulse signals from said conductors to said input terminal, and means for applying onto said conductors output pulse signals that have high and low values at said dc communications voltage level Vcomm and a predetermined voltage level VZ2 that is between said communications voltage Vcomm and said supply voltage Vdd. - View Dependent Claims (2, 3, 4, 5)
- comprising
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6. A dc signaling transmitter for communicating over a single pair of conductors which carry a dc communications voltage at a level Vcomm ;
- comprising
(a) microprocessor means having a signal input terminal Vin, a signal output terminal Vout, and a sensor input circuit coupled to a sensor transducer; (b) voltage limiting means having an input coupled to said pair of conductors to receive said dc communications voltage level Vcomm and an output coupled to said microprocessor means to supply thereto a supply voltage Vdd at a predetermined level less than said communications voltage level Vcomm ; and (c) signal output means coupled to said pair of conductors and to said microprocessor means signal input terminal and signal output terminal, including means for applying incoming pulse signals from said conductors to said input terminal, and means for applying onto said conductors output pulse signals that have high and low values at said dc communications voltage level Vcomm and a predetermined voltage level VZ2 that is between said communications voltage Vcomm and said supply voltage Vdd. - View Dependent Claims (7, 8, 9, 10)
- comprising
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11. A dc signaling receiver for receiving communications signaling over a single pair of conductors which carry a dc communications voltage at a level Vcomm ;
- comprising
(a) microprocessor means having a signal input terminal Vin, a signal output terminal Vout, and a control output circuit coupled to control an external device; (b) voltage limiting means having an input coupled to said pair of conductors to receive said dc communications voltage level Vcomm and an output coupled to said microprocessor means to supply thereto a supply voltage Vdd at a predetermined level less than said communications voltage level Vcomm ; and (c) signal input means coupled to said pair of conductors and to said microprocessor means signal input terminal and signal output terminal, including means for applying incoming pulse signals from said conductors to said input terminal, which output pulse signals have high and low values at said dc communications voltage level Vcomm and a predetermined voltage level VZ2 that is between said communications voltage Vcomm and said supply voltage Vdd. - View Dependent Claims (12, 13, 14, 15)
- comprising
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16. A two-wire coupled control system in which a one or more remote transceivers communicate with a main transceiver over a single pair of conductors which carry a dc communications voltage at a level Vcomm ;
wherein said main transceiver comprises (a) microprocessor means having a signal input terminal Vin, a signal output terminal Vout, a sensor input circuit coupled to a sensor transducer, and a control output circuit coupled to control an external device;
(b) voltage limiting means having an input coupled to said pair of conductors to receive said dc communications voltage level Vcomm and an output coupled to said microprocessor means to supply thereto a supply voltage Vdd at a predetermined level less than said communications voltage level Vcomm ; and
(c) signal input/output means coupled to said pair of conductors and to said microprocessor means signal input terminal and signal output terminal, including means for applying incoming pulse signals from said conductors to said input terminal, and means for applying onto said conductors output pulse signals that have high and low values at said dc communications voltage level Vcomm and a predetermined voltage level VZ2 that is between said communications voltage Vcomm and said supply voltage Vdd ; and
at least one of said remote transceivers also comprises (d) microprocessor means having a signal input terminal Vin, a signal output terminal Vout, and a sensor input circuit coupled to a sensor transducer;
(e) voltage limiting means having an input coupled to said pair of conductors to receive said dc communications voltage level Vcomm and an output coupled to said microprocessor means to supply thereto a supply voltage Vdd at a predetermined level less than said communications voltage level Vcomm ; and
(f) signal input/output means coupled to said pair of conductors and to said microprocessor means signal input terminal and signal output terminal, including means for applying incoming pulse signals from said conductors to said input terminal, and means for applying onto said conductors output pulse signals that have high and low values at said dc communications voltage level Vcomm and a predetermined voltage level VZ2 that is between said communications voltage Vcomm and said supply voltage Vdd.- View Dependent Claims (17)
Specification