Data bus system for motor vehicles

• US 6,282,668 B1
• Filed: 04/10/1998
• Issued: 08/28/2001
• Est. Priority Date: 04/10/1997
• Status: Expired due to Term

• Current Assignee: BMW AG (Bayerische Motoren Werke AG)
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Neudecker, Norbert
• Primary Examiner(s): Myers, Paul R.
• Application Number:
  US09/058,354
• Time in Patent Office: 1,236 Days
• Field of Search: 713/300-340, 307/10.1, 307/9.1
• US Class Current: 713/324
• 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 2016/0322 Temporary code for documents to be reclassified to G08C, H04L or H04Q
• CPC Class Codes: H04L 12/40039 Details regarding the setting of the power status of a node according to activity on the bus
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 2012/40273 the transportation system being a vehicle

Abstract

A data bus system for motor vehicles with a number of electronic bus stations, each having an input port that is connected to the motor vehicle battery to supply power to the bus stations. Each bus station is equipped with a detector circuit and a controllable switch. Each bus station is turned off in the ground state when the ignition is turned off, with the exception of the detector circuit assigned to it, by positioning the controllable switch into an open position in a selective wake state. The controllable switch of each selected bus station is closed by its detector circuit while the temporarily required data exchange between selected bus stations takes place. At least one of the bus stations is defined as the main bus station to control the wake state.

Claims

1. A data bus system for a motor vehicle, comprising a plurality of electronic bus stations, each of said bus stations having an input port that is connected with a battery of the motor vehicle to supply power to the bus stations, wherein each of said bus stations is equipped with a detector circuit and a controllable switch that turn off the supply of power to a portion of the bus station in a ground state when an ignition of the motor vehicle is turned off by opening the switch, wherein power is continuously supplied to said detector circuit, wherein, during a temporarily required data exchange between selected ones of the bus stations, the controllable switch of each of said selected bus stations is closed by it'"'"'s detector circuit during a selective wake state, and wherein at least one of the bus stations is selected as a main bus station to control said wake state.

2. A data bus system according to claim 1, wherein the controllable switch of the main bus station is initially turned on by a control signal of an external or internal additional circuit to control said wake state.

3. A data bus system according to claim 1, wherein the main bus station includes a circuit by which each said temporarily required data exchange between selected bus stations can be preset in the form of a selection telegram to be transmitted to the data bus, and a storage device, in which the selection telegrams are stored.

4. A data bus system according to claim 2, wherein the main bus station includes a circuit by which each said temporarily required data exchange between selected bus stations can be preset in the form of a selection telegram to be transmitted to the data bus, and a storage device, in which the selection telegrams are stored.

5. A data bus system according to claim 3, wherein the main bus station transmits the selection telegram to the data bus, said selection telegram being received and analyzed by the detector circuits of at least the remaining bus stations, to activate said required data exchange between said selected bus stations, wherein only said selected bus stations close their controllable switches.

6. A data bus system according to claim 4, wherein the main bus station transmits the selection telegram to the data bus, said selection telegram being received and analyzed by the detector circuits of at least the remaining bus stations, to activate said required data exchange between said selected bus stations, wherein only said selected bus stations close their controllable switches.

7. A data bus system for a motor vehicle, comprising:

a power supply which supplies power when an ignition of the motor vehicle is turned off,

a plurality of electronic bus stations connected with each other via a data bus,

each of the bus stations having a controllable switch which selectively connects the bus station to the power supply and disconnects the bus station from the power supply,

each of said bus stations having a detector circuit connected to the power supply independently of the controllable switch,

wherein when the ignition of the motor vehicle is turned off, the controllable switches disconnect the bus stations from the power supply until the detector circuits recognize that a data exchange is required between selected ones of the bus stations, at which time said detector circuits of said selected ones of the bus stations send a signal to said controllable switches of said selected ones of the bus stations to connect said selected ones of the bus stations to the power supply until said data exchange is completed, after which the controllable switches disconnect said selected ones of the bus stations from the power supply.

8. A method of exchanging data in a data bus system for a motor vehicle, said method comprising the steps of:

providing a power supply which supplies power when an ignition of the motor vehicle is turned off,

connecting a plurality of electronic bus stations with each other via a data bus,

providing each of the bus stations with a controllable switch which selectively connects each of the bus stations to the power supply and disconnects the bus station from the power supply,

providing each of said bus stations with a detector circuit connected to the power supply independently of the controllable switch,

wherein when the ignition of the motor vehicle is turned off, the controllable switches disconnect the bus stations from the power supply until the detector circuits recognize that a data exchange is required between selected ones of the bus stations, at which time said detector circuits of said selected ones of the bus stations send a signal to said controllable switches of said selected ones of the bus stations to connect said selected ones of the bus stations to the power supply until said data exchange is completed, after which the controllable switches disconnect said selected ones of the bus stations from the power supply.