Data bus for multiple components

• US 6,587,474 B1
• Filed: 07/23/1999
• Issued: 07/01/2003
• Est. Priority Date: 09/07/1996
• Status: Expired due to Term

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Griessbach, Robert
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Pizarro, Ricardo M.
• Application Number:
  US09/254,391
• Time in Patent Office: 1,439 Days
• Field of Search: 370/445, 370/446, 370/447, 370/431, 370/461, 370/462, 370/520, 370/503, 370/507, 370/509, 370/514, 370/437-439, 370/443, 370/444, 370/449, 359/118, 359/135, 359/136, 359/137
• US Class Current: 370/446
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: B60R 2021/0104 Communication circuits for data transmission
• CPC Class Codes: B60R 2021/01075 between the airbag control unit and pyrotechnic fuses or equivalent actuators
• CPC Class Codes: B60R 2021/01115 specific data frames
• CPC Class Codes: H04L 12/4015 by scheduling the transmission of messages at the communication node
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 12/44 Star or tree networks

Abstract

In a data bus which is shared by several components, the components possess a hierarchical transmission token and are synchronized by a synchronization pulse. A clock signal of the synchronization pulse has a rate which is between the duration of transmission of the component with the highest priority token and the cumulative duration of transmission of all components.

Claims

1. Data bus for multiple components, comprising:

a beam wave guide;

a plurality of components coupled to the beam wave guide; and

an active star coupler coupled to the beam wave guide;

wherein

the components have a predetermined hierarchical transmission authorization;

an order of transmissions of the respective components is controlled via a synchronizing pulse, said components transmitting data via said data bus between consecutive synchronizing pulses in an order determined according to said hierarchical transmission authorizations; and

a cycle time between consecutive synchronizing pulses resides between a duration of a transmission of a component having a highest priority ranking and a cumulative transmission time of all components.

2. The data bus according to claim 1, wherein if a higher ranking component does not transmit, a lower ranking component has a transmission authorization in a time interval which is measured from a transmission time of a component having a highest priority ranking, based on a maximum transmission time of a signal on the data bus.

3. The data bus according to claim 1, wherein a component does not transmit if a time period remaining between a transmission authorization for said component and a time for outputting a following synchronizing pulse is shorter than a duration of transmission of the component.

4. The data bus according to claim 2, wherein a component does not transmit if a time period remaining between a transmission authorization for said component and a time for outputting a following synchronizing pulse is shorter than a duration of transmission of the component.

5. The data communication network according to claim 1, wherein the plurality of subscriber components are interconnected via the active star coupler.

6. The data bus according to claim 1, wherein the components send a status signal in a normal mode.

7. The data bus according to claim 2, wherein the components send a status signal in a normal mode.

8. The data bus according to claim 1, wherein the synchronizing pulse has different durations which correspond to different conditions of devices assigned to the data bus.

9. The data bus according to claim 2, wherein the synchronizing pulse has different durations which correspond to different conditions of devices assigned to the data bus.

10. The data bus according to claim 8, wherein the conditions of devices assigned to the data bus are defined by a transmission mode of a specific component.

11. The data bus according to claim 1, wherein the synchronizing pulse is transmitted by a component.

12. The data bus according to claim 2, wherein the synchronizing pulse is transmitted by a component.

13. A method of operating a data network which includes a plurality of subscriber components coupled in data communication via a data bus that is controlled by a bus master, said method comprising:

said bus master generating a train of synchronization pulses;

between consecutive synchronization pulses, said subscriber components transmitting data via said data bus in an order determined according to a predetermined transmission priority hierarchy;

wherein a cycle time between consecutive synchronization pulses is greater than a duration of a transmission of a subscriber component having highest priority and less than a cumulative transmission time necessary for all subscriber components to transmit via the data bus.

14. The method according to claim 13, wherein a particular subscriber component does not transmit if a time remaining prior to expiration of a current cycle is less than a duration required for transmission by the subscriber component.

15. The method according to claim 13, wherein:

following a particular synchronization pulse, a first next consecutive synchronous pulse is delayed if a component has not completed transmission of data prior to the end of a current cycle; and

a second next consecutive synchronization pulse is generated at a time measured from said particular synchronization pulse.

16. A data communication network having a plurality of subscriber components coupled in data communication via a data bus that is controlled by a bus master, wherein:

said bus master generates a train of synchronization pulses;

between consecutive synchronization pulses, said subscriber components transmit data via said data bus in an order determined according to a predetermined transmission priority hierarchy; and

a cycle time between consecutive synchronization pulses is greater than a duration of a transmission of a subscriber component having highest priority and less than a cumulative transmission time necessary for all subscriber components to transmit via the data bus.

17. The data communication network according to claim 16, wherein a particular subscriber component does not transmit if a time remaining prior to expiration of a current cycle is less than a duration required for transmission by the subscriber component.

18. The data communication network according to claim 16, wherein:

following a particular synchronization pulse, a first next consecutive synchronous pulse is delayed if a component has not completed transmission of data prior to the end of a current cycle; and

a second next consecutive synchronization pulse is generated at a time measured from said particular synchronization pulse.