COMMUNICATIONS SYSTEM, A HVAC SYSTEM EMPLOYING THE SAME AND A METHOD OF MANUFACTURING A COMPONENT FOR THE HVAC SYSTEM

• US 20120158932A1
• Filed: 12/16/2010
• Published: 06/21/2012
• Est. Priority Date: 12/16/2010
• Status: Active Grant

• Current Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Original Assignee: Lennox Industries Incorporated (Lennox International Incorporated)
• Inventors: Grohman, Wojciech
• Granted Patent: US 8,838,763 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]

Abstract

A communications network, a HVAC system employing a communications system and a method of manufacturing a component for the HVAC system are disclosed. In one embodiment, the communications network includes: (1) a dominant node having a predetermined coupling impedance and (2) a plurality of end nodes coupled to the dominant node, each of the plurality having an end node coupling impedance, wherein a total of each the end node coupling impedance and the predetermined coupling impedance is substantially a defined maximum loading impedance for the communication network.

Claims

1. A communication network, comprising:

a dominant node having a predetermined coupling impedance;

a plurality of end nodes coupled to said dominant node, each of said plurality having an end node coupling impedance, wherein a total of each said end node coupling impedance and said predetermined coupling impedance is substantially a defined maximum loading impedance for said communication network.

2. The communication network as recited in claim 1 wherein said defined maximum loading impedance is based on a characteristic of a transceiver at said dominant node.

3. The communication network as recited in claim 2 wherein said transceiver is a CAN compliant transceiver.

4. The communication network as recited in claim 2 wherein said transceiver is a RS-485 compliant transceiver.

5. The communication network as recited in claim 1 wherein said predetermined coupling impedance has a resistance within a range of 50 ohms to 200 ohms.

6. The communication network as recited in claim 1 wherein said plurality of end nodes is coupled to said dominant node via copper wire.

7. The communication network as recited in claim 1 wherein a maximum number of said plurality of end nodes is in a range of one to thirty-one.

8. The communication network as recited in claim 1 wherein each said end node coupling impedance is substantially the same.

9. The communication network as recited in claim 1 wherein at least two of said end node coupling impedances are not substantially the same.

10. The communication network as recited in claim 1 wherein communication lengths between said plurality of end nodes and said dominant node vary.

11. The communication network as recited in claim 1 wherein said dominant node and said plurality of end nodes are coupled together in a free-topology network.

12. The communication network as recited in claim 1 wherein said plurality of end nodes are coupled together in parallel.

13. The communication network as recited in claim 1 wherein an end node coupling impedance of one of said plurality of end nodes is based on said predetermined coupling impedance and end node coupling impedances of said remaining plurality of end nodes.

14. The communication network as recited in claim 1 wherein said communicating network is a building communication network.

15. The communication network as recited in claim 1 wherein said communicating network is a HVAC communications and control network.

16. The communication network as recited in claim 1 wherein said predetermined coupling impedance is embedded in an electronic controller.

17. The communication network as recited in claim 1 wherein at least one of said end node coupling impedances is embedded in an electronic controller.

18. A Heating, Ventilation and Air Conditioning (HVAC) system, comprising:

an air handler configured to condition and circulate air for said HVAC system;

an air handler controller for said HVAC system configured to control operation of said air handler, said air handler controller including interface circuitry having a predetermined coupling impedance and configured to couple said air handler controller to components of said HVAC system via a communications network of said HVAC system, wherein a total of said predetermined coupling impedance and an end node coupling impedance at each of said components is substantially a defined maximum loading impedance for said communications network.

19. The HVAC system as recited in claim 18 wherein at least one of said components is a comfort sensor and said end node coupling impedance at said comfort sensor is based on said predetermined coupling impedance and end node coupling impedances of said remaining components.

20. A method of manufacturing a component for a HVAC system, comprising:

obtaining an end node coupling impedance for a component of said HVAC system; and

providing said component having said end node coupling impedance.