Distributed control and monitoring system

• US 20050251701A1
• Filed: 01/07/2003
• Published: 11/10/2005
• Est. Priority Date: 01/07/2002
• Status: Active Grant

• Current Assignee: Callahan Cellular LLC (Intellectual Ventures LLC)
• Original Assignee: Xinshu Management LLC (Intellectual Ventures LLC)
• Inventors: Fredriksson, Lars-Berno
• Granted Patent: US 7,478,234 B2
• Time in Patent Office: Days
• US Class Current: 713/500
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0805 by checking availability

Abstract

In a more efficient distributed control or monitoring arrangement there are devices in control, monitoring and/or vehicle systems that comprise locally deployed module units that carry out one or more functions, and one or more links connecting the units. The respective module unit is connected to a link via a connection arrangement or a connection point and requisite communication device for the CAN protocol. A CAN control unit is arranged to receive indication of falling edges on the bus in question, and to carry out measurement of the time between falling edges using clock pulses in its clock function. Information from two or more such measurements forms the basis for calculation of a bit frequency currently used in communication on the bus by active module units connected to the same. The respective module unit comprises one or more communication devices that are free-standing or integrated in a microprocessor chip comprising at least a function performing microprocessor that is arranged with or interworks with at least one memory area. The content in the memory of a first module unit is readable and/or writable via the link from a second module unit in the system without significant assistance from the function performing microprocessor in the first module unit.

Claims

1. Distributed control or monitoring arrangement comprising devices in or belonging to control, monitoring and/or vehicle systems that comprise separate or locally deployed (distributed) module units, (nodes) that carry out one or more functions, and one or more links connecting the units, the respective module unit being connected to the link in question via a connection arrangement or a connection point or requisite communication device for the CAN protocol, characterized in that the connection arrangement or connection point for a first module unit comprises one or more communication devices (for example CAN Controllers and CAN Transceivers) that are free-standing or integrated in a microprocessor chip comprising at least a microprocessor (CPU) which is arranged to carry out instructions synchronously with and interworking with the CAN control unit'"'"'s state machine.

2. Arrangement as claimed in claim 1, characterized in that a CAN control unit (CAN Controller) is arranged to receive indication of falling edges on the link (bus) concerned, in that the CAN control unit is arranged to carry out measurement of the time at and/or between falling edges using clock pulses in its clock function, in that information from two or more such measurements forms the basis for calculation of a bit frequency currently used in communication on the link (bus) by active module units (nodes) connected to the link.

3. Arrangement as claimed in claim 2, characterized in that one of the said module units (nodes) in the system is arranged to transmit a message with one or more sequences of previously known bit patterns in order to make it easier for module units (nodes) connected to the system with incorrectly set bit frequency to determine the correct bit frequency and set themselves to this.

4. Arrangement as claimed in claim 3, characterized in that the bit pattern is constructed of even multiples of the bit time for the bit speed used in the system.

5. Arrangement as claimed in claim 3, characterized in that the bit pattern corresponds to all or part of a CAN identifier and/or existing data field and/or DLC field.

6. Arrangement as claimed in claim 5, characterized in that the bit pattern is arranged to be able to be connected with matching of DLC with a value larger than eight.

7. Arrangement as claimed claim 2, characterized in that the system is arranged to work with messages with dual function, namely to contain a bit pattern for measurement of the used bit time, and to indicate that the DLC field and/or data field contains further information for making possible the integration of the module unit (node) into the system.

8. Arrangement as claimed in claim 2, characterized in that one or more units that are temporarily or permanently connected, that determine the system function and are at a higher level than the module units are arranged to carry out reading and/or writing in the respective memory area concerned without significant assistance from the respective function performing microprocessor.

9. Arrangement as claimed in claim 1, characterized in that the function performing microprocessor is arranged to carry out writing and reading of content/information in the memory area concerned.

10. Arrangement as claimed in claim 1, characterized in that the function performing microprocessor in the module unit concerned and/or in one or more of the other module units connected to the link is/are arranged to write-protect the said content/information.

11. Arrangement as claimed in claim 10, characterized in that the write-protection function employed works with cryptography and/or access codes.

12. Arrangement as claimed in claim 1, characterized in that the memory area or the memory contains an identification of the module unit.

13. Arrangement as claimed in claim 1, characterized in that a message is arranged to initiate reading or writing when it appears on the link with a previously determined CAN identifier.

14. Arrangement as claimed in claim 13, characterized in that the microprocessor in the module is arranged to initiate reading or writing by means of a command.

15. Arrangement as claimed in claim 13, characterized in that bit timing registers are arranged to be readable and writable via the link.

16. Arrangement as claimed in claim 13, characterized in that filters for receiving and/or sending messages are arranged to be readable and writable via the link.

17. Arrangement as claimed in claim 13, characterized in that the algorithm for receiving and/or sending can be downloaded to the control unit(s) (CAN Controller(s)) via the link.

18. Arrangement as claimed in claim 13, characterized in that instructions for the appearance/function of the control unit(s) (CAN Controller(s)) can be downloaded to the control unit (CAN Controller) via the link.

19. Arrangement as claimed in claim 2, characterized in that the system works or interworks with the Bluetooth protocol.

20. Arrangement as claimed in claim 1, characterized in that one and the same CAN identifier that sends system control messages also sends the bit pattern concerned.

21. Arrangement as claimed in claim 1, characterized in that the CAN control unit can be set in a mode in which it transmits a dominant pulse upon command.

22. Arrangement as claimed in claim 1, characterized in that the CAN control unit can be set in a mode in which it transmits a dominant pulse upon the detection of a falling edge on the bus.

23. Arrangement as claimed in claim 21, characterized in that the dominant pulse is one bit quantum in length.

24. Arrangement as claimed in claim 1, characterized in that the CAN control unit can be set in a mode in which it does not participate in the CAN communication, but captures or receives the clock value transmits a dominant pulse upon the detection of a failing edge on the bus.

25. Arrangement as claimed in claim 1, characterized in that the CAN control unit works synchronously with the CPU during all or parts of the reception and/or transmission sequence.

26. Arrangement as claimed in claim 1, characterized in that the CAN control unit and the CPU are arranged to be driven by a clock where the clock pulses are adjusted to follow the frequency of a global clock in the system.

27. Arrangement as claimed in claim 1, characterized in that the CAN control unit and the CPU are arranged to work synchronously with global time.

28. Arrangement as claimed in claim 1, characterized in that the CPU is arranged to read and/or write in the send buffer and/or receive buffer of the CAN control unit while there is CAN traffic on the bus.

29. Arrangement as claimed in claim 1, characterized in that the CAN control unit has a common send buffer and receive buffer.

30. Arrangement as claimed in claim 1, characterized in that it comprises a clock unit that can be driven by an oscillator, in that a pre-scaler is arranged to adjust pulse trains outgoing from the clock unit/oscillator, in that the pre-scaler is arranged to generate an outgoing clock pulse after a number of pulses N from the oscillator, in that the outgoing pulse is arranged to be able to be adjusted to N+1 or N1, when a value in a phase adjustment register is reached resulting in adjustment of the clock unit and in that statistical errors present can be adjusted by a value in a register for statistical errors being added to the local time.

31. Arrangement as claimed in claim 30, characterized in that the CPU is arranged to calculate the said register values and write them in the register.

32. Arrangement as claimed in claim 1, characterized in that the CAN control unit or connection arrangement in a first module unit is arranged with at least one memory area, the content of which is readable and/or writable via the link from a second module unit in the system without significant assistance from any function performing microprocessor in the first module unit.