Local communication bus system and apparatuses for use in such a system

• US 5,815,082 A
• Filed: 03/18/1992
• Issued: 09/29/1998
• Est. Priority Date: 03/22/1991
• Status: Expired due to Fees

• Current Assignee: D2B Systems Co. Ltd. (Koninklijke Philips N.V.)
• Original Assignee: DB2 Systems Company Limited
• Inventors: Welmer, Harm J.
• Primary Examiner(s): TON, DANG T
• Application Number:
  US07/853,373
• Time in Patent Office: 2,386 Days
• Field of Search: 340/825.07, 340/825.63, 340/825.5, 340/825.51, 340/825.08, 340/504, 340/505, 340/500, 340/825.52, 340/870.03, 370/85.1, 370/85.8, 370/241, 370/245, 370/247, 370/251, 370/252, 370/257, 370/364, 370/450, 370/449, 370/451
• US Class Current: 340/3.51
• CPC Class Codes: H04B 1/205 with control bus for exchanging commands between units
• CPC Class Codes: H04N 5/445 for displaying additional information H04N5/50 takes precedence

Abstract

A number of domestic audio/video apparatuses (10-14) are connected to a serial control bus (D2B, 16). Each apparatus is addressable via the bus as a device and contains functional elements addressable on subdevices. One apparatus (14) includes an on-screen display subdevice (41) and a first control subdevice (24). Subdevice status messages are defined whereby a control subdevice can ask to be informed of the status of a further subdevice (e.g. 26), and in particular to be informed automatically of any change in status without the need for continuous polling of subdevices. The subdevice status messages can be used to obtain early confirmation of a signal path being established through the system.

Claims

1. A local communication bus system comprising a serial control bus coupled to a plurality of devices, each device comprising a control subdevice and a further subdevice, each device, control subdevice and further subdevice being addressable using said serial control bus, wherein said control subdevice comprises means for generating a first status request message addressed to said further subdevice, and wherein said further subdevice comprises:

a) means responsive to said first status request message for generating a first further subdevice status message to said control subdevice; and

b) means responsive to a change in status in said further subdevice for generating an updated further subdevice status message to said control subdevice without receiving an additional status request message from said control subdevice, if and only if said further subdevice has previously received said first status request message.

2. The system of claim 1, wherein said first status request message comprises a field indicating the desirability of said updated further subdevice status message.

3. The system of claim 1, wherein said control subdevice comprises means for generating a verification request message addressed to said further subdevice, said further subdevice being responsive to said verification request message so as to generate an indication message indicating if said updated further subdevice status message will be generated.

4. The system of claim 1, wherein said first further subdevice status message comprises a plurality of status variables and said first status request message is a status request message which is not specific to one of said status variables, and wherein said updated further subdevice status message is transmitted automatically in response to a change in one of said status variables.

5. A device, including:

a control subdevice and a further subdevice, said control subdevice including facilities for sending a status request message indicating receptiveness of said control subdevice to status update messages from said further subdevice; and

,

further subdevice facilities responsive to a change in status of said further subdevice for automatically generating a status update message, without the necessity of receiving an additional status request message from said control subdevice, and for automatically sending a further status update message to said control subdevice if, and only if, said further subdevice has previously received said status request message from said control subdevice.

6. The device as set forth in claim 5, wherein a first type of said status request message identifies a plurality of device status variables for which status updating is requested.

7. The device as set forth in claim 6, wherein a second type of said status request message identifies a selected subset of said plurality of device status variables for which status updating is requested.

8. The device as set forth in claim 6, wherein said further subdevice facilities are responsive only to a change in status of any one or more of said plurality of device status variables for generating said status update message.

9. The device as set forth in claim 7, wherein said further subdevice facilities are responsive only to a change in status of anyone or more of said subset of said plurality of device status variables for generating said status update message.

10. The device as set forth in claim 5, wherein the device comprises a television.

11. The device as set forth in claim 5, wherein the device comprises a VCR.

12. The device as set forth in claim 5, wherein the device comprises a satellite broadcast tuner.

13. The device as set forth in claim 10, wherein:

said control subdevice comprises an audio/video controller, and,

said further subdevice comprises a tuner subdevice.

14. The device as set forth in claim 11, wherein:

said control subdevice comprises an audio/video controller; and

,

said further subdevice comprises a videotape record/replay deck.

15. The device as set forth in claim 12, wherein:

said control subdevice comprises an audio/video controller; and

,

said further subdevice comprises a tuner subdevice.

16. The device as set forth in claim 6, wherein one of said device status variables is volume setting of the device.

17. The device as set forth in claim 6, wherein one of said device status variables is channel setting of the device.

22. The device as set forth in claim 5, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

23. The device as set forth in claim 6, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

24. The device as set forth in claim 7, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

25. The device as set forth in claim 8, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

26. The device as set forth in claim 9, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

27. The device as set forth in claim 16, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

28. The device as set forth in claim 11, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

29. The device as set forth in claim 12, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

18. A device, including:

a control subdevice and a plurality of further subdevices, said control subdevice including facilities for sending a status request message indicating readiness of said control subdevice to receive status update messages from said further subdevices; and

,

wherein each of said further subdevices includes a communication facility responsive to a change in status of its respective further subdevice for automatically generating a status update message, without the necessity of receiving an additional status request message from said control subdevice, and for automatically sending a further status update message to said control subdevice if, and only if, its respective further subdevice has previously received said status request message from said control subdevice.

19. The device as set forth in claim 18, wherein said communication facility of each said further subdevice is responsive to a change in status of its respective further subdevice for automatically sending said further status update message to only said control subdevice.

20. The device as set forth in claim 18, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.

21. The device as set forth in claim 19, wherein:

the device is coupled to a local communication bus system to which a plurality of other devices are also coupled, said local communication bus system including a serial control bus; and

,

said control device and each of said further subdevices is addressable via said serial control bus.