Method of and apparatus for cancelling a pending AV/C notify command

• US 7,003,604 B2
• Filed: 10/04/2001
• Issued: 02/21/2006
• Est. Priority Date: 10/04/2001
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Brelin, Jon Ebbe
• Primary Examiner(s): Myers, Paul R.
• Application Number:
  US09/971,998
• Publication Number:
  US 20030070015A1
• Time in Patent Office: 1,601 Days
• Field of Search: 710/100, 710/105, 709/230, 370/912, 370/546, 340/825.37
• US Class Current: 710/105
• CPC Class Codes: G06F 13/387 for adaptation of different data processing systems to different peripheral devices, e.g. protocol converters for incompatible systems, open system
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• 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 67/54 Presence management, e.g. monitoring or registration for receipt of user log-on information, or the connection status of the users

Abstract

The method and apparatus for cancelling a pending notify command of the present invention includes a mechanism which allows a controlling device to cancel a pending notify command. A controlling device has the ability to cancel a pending notify command, by sending a cancelling command to a target device while the notify command is pending. Preferably, the cancelling command is a status command. Alternatively, the cancelling command is a duplicate notify command. In a still further alternative embodiment, the cancelling command is a notify cancel command. A target device which receives a notify command from a controlling device, first sends an interim response to the controlling device. When the state of the target device changes, the target device then sends a notify response to the controlling device. Before the state of the target device changes, while the notify command is pending, if the target device receives the cancelling command, the target device then cancels the pending notify command.

Claims

1. A method of cancelling a pending notify command at a target device comprising:

a. sending a cancelling command over a network from a controlling device to the target device, wherein the cancelling command is a status command sent while the pending notify command is pending; and

b. cancelling the pending notify command at the target device when the cancelling command is received while the pending notify command is pending.

2. The method as claimed in claim 1 wherein the network substantially complies with a version of the IEEE 1394 standard.

3. The method as claimed in claim 2 wherein the cancelling command substantially complies with a version of the AV/C protocol.

4. The method of claim 1 wherein the cancelling command is a status command sent after the controlling device determines cancellation is appropriate.

5. A target device for communicating with a controlling device over a network, the target device comprising:

a. means for communicating with the controlling device over the network, the means for communicating including ability to receive a notify command from the controlling device, issue an interim response to the notify command to the controlling device and receive a cancelling command from the controlling device, wherein the cancelling command is a status command sent while the pending notify command is pending; and

b. means for cancelling coupled to the means for communicating for cancelling a pending notify command if a cancelling command is received from the controlling device while the pending notify command is pending.

6. The target device as claimed in claim 5 wherein the network substantially complies with a version of the IEEE 1394 standard.

7. The target device as claimed in claim 6 wherein the cancelling command substantially complies with a version of the AV/C protocol.

8. A target device configured to communicate with a controlling device over a network, the target device comprising:

a. an interface circuit configured to communicate with the controlling device over the network, the interface circuit including ability to receive a notify command from the controlling device, issue an interim response to the notify command and receive a cancelling command from the controlling device, wherein the cancelling command is a status command sent while the pending notify command is pending; and

b. a control circuit coupled to the interface circuit to cancel a pending notify command if a cancelling command is received from the controlling device while the pending notify command is pending.

9. The target device as claimed in claim 8 wherein the network substantially complies with a version of the IEEE 1394 standard.

10. The target device as claimed in claim 9 wherein the cancelling command substantially complies with a version of the AV/C protocol.

11. A network of devices coupled together comprising:

a. a controlling device configured to send a cancelling command to cancel a pending notify command, wherein the cancelling command is a status command sent while the pending notify command is pending; and

b. a target device including;

i. an interface circuit configured to communicate with the controlling device to receive the cancelling command from the controlling device; and

ii. a control circuit coupled to the interface circuit to cancel a pending notify command if the cancelling command is received from the controlling device while the pending notify command is pending.

12. The network of devices as claimed in claim 11 wherein the target device is coupled to the controlling device over a network substantially complying with a version of the IEEE 1394 standard.

13. The network of devices as claimed in claim 11 wherein the cancelling command substantially complies with a version of the AV/C protocol.

14. A network of devices coupled together by a standard IEEE 1394 serial bus comprising:

a. a controlling device in communication with the standard IEEE 1394 serial bus and configured for sending a cancelling command over the standard IEEE 1394 serial bus, wherein the cancelling command is a status command sent while the pending notify command is pending; and

b. a target device in communication with the standard IEEE 1394 serial bus and configured for receiving the cancelling command and cancelling a pending notify command if the cancelling command is received while the pending notify command is pending.

15. A method of cancelling a pending notify command at a target device comprising:

a. sending a cancelling command over a network from a controlling device to the target device, wherein the cancelling command is a duplicate of the pending notify command sent while the pending notify command is pending; and

b. cancelling the pending notify command at the target device when the cancelling command is received while the pending notify command is pending.

16. The method as claimed in claim 15 wherein the network substantially complies with a version of the IEEE 1394 standard.

17. The method as claimed in claim 16 wherein the cancelling command substantially complies with a version of the AV/C protocol.

18. The device of claim 15 wherein the cancelling command is a duplicate of the pending notify command sent after the controlling device determines cancellation is appropriate.

19. A target device for communicating with a controlling device over a network, the target device comprising:

a. means for communicating with the controlling device over the network, the means for communicating including ability to receive a notify command from the controlling device, issue an interim response to the notify command to the controlling device and receive a cancelling command from the controlling device, wherein the cancelling command is a duplicate of the pending notify command sent while the pending notify command is pending; and

b. means for cancelling coupled to the means for communicating for cancelling a pending notify command if a cancelling command is received from the controlling device while the pending notify command is pending.

20. The target device as claimed in claim 19 wherein the network substantially complies with a version of the IEEE 1394 standard.

21. The target device as claimed in claim 20 wherein the cancelling command substantially complies with a version of the AV/C protocol.

22. A target device configured to communicate with a controlling device over a network, the target device comprising:

a. an interface circuit configured to communicate with the controlling device over the network, the interface circuit including ability to receive a notify command from the controlling device, issue an interim response to the notify command and receive a cancelling command from the controlling device, wherein the cancelling command is a duplicate of the pending notify command sent while the pending notify command is pending; and

b. a control circuit coupled to the interface circuit to cancel a pending notify command if a cancelling command is received from the controlling device while the pending notify command is pending.

23. The target device as claimed in claim 22 wherein the network substantially complies with a version of the IEEE 1394 standard.

24. The target device as claimed in claim 23 wherein the cancelling command substantially complies with a version of the AV/C protocol.

25. A network of devices coupled together comprising:

a. a controlling device configured to send a cancelling command to cancel a pending notify command, wherein the cancelling command is a duplicate of the pending notify command sent while the pending notify command is pending; and

b. a target device including;

i. an interface circuit configured to communicate with the controlling device to receive the cancelling command from the controlling device; and

ii. a control circuit coupled to the interface circuit to cancel a pending notify command if the cancelling command is received from the controlling device while the pending notify command is pending.

26. The network of devices as claimed in claim 25 wherein the target device is coupled to the controlling device over a network substantially complying with a version of the IEEE 1394 standard.

27. The network of devices as claimed in claim 25 wherein the cancelling command substantially complies with a version of the AV/C protocol.

28. A network of devices coupled together by a standard IEEE 1394 serial bus comprising:

a. a controlling device in communication with the standard IEEE 1394 serial bus and configured for sending a cancelling command over the standard IEEE 1394 serial bus, wherein the cancelling command is a duplicate of the pending notify command sent while the pending notify command is pending; and

b. a target device in communication with the standard IEEE 1394 serial bus and configured for receiving the cancelling command and cancelling a pending notify command if the cancelling command is received while the pending notify command is pending.

29. A method of communicating between a controlling device and a target device comprising:

a. sending a notify command from the controlling device to the target device thereby establishing a pending notify command;

b. sending the notify command a second time from the controlling device to the target device, while the pending notify command is pending, as a cancelling command; and

c. cancelling the pending notify command at the target device when the notify command is received while the pending notify command is pending.

30. The method of claim 29 wherein the notify command is sent for a second time as a cancelling command after the controlling device determines cancellation is appropriate.