Multiple instance single value identifiers environmental control communication method and system

• US 6,353,775 B1
• Filed: 07/28/1998
• Issued: 03/05/2002
• Est. Priority Date: 07/28/1998
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell International Inc.
• Inventors: Nichols, Steven C.
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): Mai, Rijue
• Application Number:
  US09/123,651
• Time in Patent Office: 1,316 Days
• Field of Search: 700/276, 700/277, 700/278, 710/9, 710/10, 710/11, 710/12, 710/13
• US Class Current: 700/276
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A method of communicating between a plurality of devices in a controller area network is disclosed. The method includes authorizing a first device to transmit messages with a first identifier over the network, the first device transmitting a first message with the first identifier and a first value, and the devices which receive the first message assuming the first value as their respective values. The method may be used with a number of devices and a listening device in a system. At startup of the system, any device which saved its value in a non-volatile memory will become the master of the identifier and transmit a message with the value over the network. Devices which did not save their values in non-volatile memories will transmit requests for the data value. If they do not receive any response, they will become the master and transmit messages with their data. Devices which receive the message will assume the value as theirs. If the value at a device is changed, that device will become master and transmit a message with its value.

Claims

1. A method of communicating between a plurality of devices in an environmental control network, the method comprising:

authorizing a first device to transmit messages with a first identifier over the network;

transmitting a first message with the first identifier and a first value from the first device on the network for receipt by at least one second device;

the second device which receives the first message assuming the first value as its respective value;

the first and second devices monitoring their respective values for changes and transmitting their respective values if there are changes to their respective values; and

deauthorizing the first device from transmitting messages with the first identifier if the first device receives a message with the first identifier.

2. The method of claim 1, wherein the step of authorizing the first device to transmit messages is carried out after the first device has not received any message within a time period.

3. The method of claim 1, wherein the step of authorizing the first device to transmit messages is carried out after the first device has not received an answer to a request with the first identifier which was transmitted over the network.

4. The method of claim 1, wherein the second device is already authorized to transmit messages with the first identifier when it receives the first message, further comprising the step of deauthorizing the second device from transmitting messages with the first identifier after it receives the first message.

5. The method of claim 1, further comprising the step of the first device storing the first value in a non-volatile memory prior to the step of authorizing the first device to transmit messages with the first identifier.

6. The method of claim 1, wherein the second device had not stored a value with the first identifier in a non-volatile memory, further comprising the step of the second device transmitting a request with the first identifier over the network.

7. The method of claim 1, wherein the first value is selected from the group consisting of the commands heat, cool, and off.

8. The method of claim 1, wherein the first value is selected from the group consisting of the commands fan on and fan auto.

9. The method of claim 1, further comprising the step of a third device, which is not authorized to transmit messages, receiving a user-input change in its value and thereby authorizing itself to transmit messages, and transmitting a message.

10. The method of claim 1, further comprising the step of a third device, which is not authorized to transmit messages, detecting a condition that a message should have been received but it was not, whereby the third device authorizes itself to transmit messages, and transmits a message.

11. The method of claim 1, further including the step of a third device transmitting a message to the first device with instructions for the first device to change its value.

12. An environmental control network with a network bus, the network comprising:

a plurality of devices connected to the network bus, each device including;

means for transmitting messages over the network including a first identifier and a value;

means for monitoring the network bus for any messages transmitted on the network bus;

means for terminating transmission of further messages if the device receives a message with the first identifier;

means for storing the value at the device;

means for changing the value at the device; and

means for actuating the means for transmitting to transmit the value as changed.

13. The system of claim 12, wherein at least one of the devices further includes means for transmitting a message if the device has not received a message during a time period.

14. The system of claim 12, wherein at least one device further includes a memory for storing the value.

15. The system of claim 14, wherein at least one device other than the device including the memory further includes means for transmitting a request over the network.

16. The system of claim 12, wherein at least one device further includes means for transmitting a message if the device detects a condition that an expected message was not received.

17. The system of claim 12, further including means for changing the value in response to a message from another device.

18. An environmental control system, comprising:

a plurality of devices;

a serial network bus interconnecting the devices; and

each of the devices having at least one mode and including;

means for storing in memory a mode identifier and a status value of the mode;

means for displaying the status value of the mode stored in memory;

means for transmitting a message including the mode identifier and the status value so stored in memory;

means for monitoring messages transmitted on the bus;

means for terminating transmission of messages upon detection of a message with a mode identifier the same as the stored mode identifier and means for storing a status value contained in the message so as the status value of the mode stored in memory, whereby all devices display the status value of the last device to transmit on the network;

user interface means for changing the status value of the mode stored in memory; and

means for detecting a change of the status value of the mode stored in memory and initiating transmission of a message including the status value as changed.

19. A method of communicating between a plurality of devices in an environmental control network, the method comprising:

authorizing a first environmental control device to transmit messages with a first identifier over the network;

transmitting a first message with the first identifier and a first value from the first device on the network for receipt by at least one second environmental control device;

the second environmental control device which receives the first message assuming the first value as its respective value;

the first and second environmental control devices monitoring their respective values for changes and transmitting their respective values if there are changes to their respective values; and

deauthorizing the first environmental control device from transmitting messages with the first identifier if the first environmental control device receives a message with the first identifier.