Data bus for several users

• US 6,898,656 B2
• Filed: 04/03/2002
• Issued: 05/24/2005
• Est. Priority Date: 10/04/1999
• Status: Expired due to Fees

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Griessbach, Robert, Peller, Martin
• Primary Examiner(s): Lefkowitz, Sumati
• Assistant Examiner(s): Knoll, Clifford
• Application Number:
  US10/114,325
• Publication Number:
  US 20020166014A1
• Time in Patent Office: 1,147 Days
• Field of Search: 710/305, 710/306, 710300-304, 710/313, 710/314, 710/62, 710/63, 710/107, 709/208, 709/209, 709/210, 709/211, 714/2, 714 10- 12, 714/55, 714/23, 713/375, 713/400, 713/500
• US Class Current: 710/305
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling

Abstract

In the case of a data bus for several users, the users have hierarchical transmission authorizations; the users are synchronized by a synchronization signal; and the communication of the user with the highest priority, which can be emitted at regular time intervals by this user, serves as a synchronization signal.

Claims

1. Data bus for several users, wherein

a) the users possess hierarchical data communication signal transmission authorizations,

b) the users are synchronized by a synchronization signal, and

c) the data communication signal of a user with the highest priority, which data communication signal the user emits at regular intervals, is used as the synchronization signal in place of a clock pulse generator synchronization signal.

2. Data bus according to claim 1, wherein the highest ranking user emits its data communication signal at regular intervals when it does not receive the clock pulse generator synchronization signal.

3. Data bus according to claim 1, wherein the user with the second highest priority emits its data communication signal at regular intervals when it does not receive the clock pulse generator synchronization signal, or the data communication signal of the user with the highest priority.

4. Data bus according to claim 2, wherein the user with the second highest priority emits its data communication signal at regular intervals when it does not receive the clock pulse generator synchronization signal, or the data communication signal of the user with the highest priority.

5. A method for operating a data bus on which several users are arranged, the method comprising the acts of:

assigning hierarchical data communication signal transmission authorization to the several users on the data bus;

synchronizing hierarchical transmission of the users via a synchronization signal; and

using as the synchronization signal, the data communication signals of the user assigned a highest priority that is capable of transmitting said data communication signals at regular intervals in place of a clock pulse generator synchronization signal.

6. The method according to claim 5, wherein the act of using comprises the acts of:

determining whether a normal clock pulse generated synchronization signal is received by the highest ranking user; and

transmitting data communication signals of the highest ranking user at regular intervals when the normal clock pulse generated synchronization signal is not received.

7. The method according to claim 5, further comprising the acts of:

transmitting data communication signals of the user with the second highest priority at regular intervals to form the synchronization signal when a normal clock pulse generated synchronization signal and data communication signals of the highest ranking user are not received.

8. The method according to claim 6, further comprising the acts of:

transmitting data communication signals of the user with the second highest priority at regular intervals to form the synchronization signal when a normal clock pulse generated synchronization signal and data communication signals of the highest ranking user are not received.