System and method for automatically selecting baud rate in a can network

Patent metadata

Field	Value
Publication number	US-2016330044-A1
Application number	US-201315108919-A
Country	US
Kind code	A1
Filing date	Dec 30, 2013
Priority date	Dec 30, 2013
Publication date	Nov 10, 2016
Grant date	—

Abstract

According to various aspects and embodiments, a device is provided. The device includes a memory, a Controller Area Network (CAN) controller coupled to a CAN bus, at least one processor coupled to the memory and the CAN controller. The at least one processor is configured to set the CAN controller to a first baud rate, determine a second baud rate, and send, in response to determining the second baud rate, a baud rate change request via the CAN bus, wherein the baud rate change request includes a least an identifier of the second baud rate.

First claim

What is claimed is:

1 . A device comprising:
a memory; a Controller Area Network (CAN) controller coupled to a CAN bus; at least one processor coupled to the memory and the CAN controller, the at least one processor being configured to: set the CAN controller to a first baud rate; determine a second baud rate; and send, in response to determining the second baud rate, a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the second baud rate.

2 . The device of claim 1 , wherein the at least one processor is further configured to:
determine a timeout has elapsed; send, in response to determining the timeout has elapsed, a baud rate confirmation request via the CAN bus; and set the CAN controller to the second baud rate.

3 . The device of claim 2 , wherein the at least one processor is further configured to:
receive a data frame from at least one device coupled to the CAN bus; determine, in response to receiving the data frame, that the CAN bus does not support the second baud rate based on an error count of the CAN controller; determine a lower baud rate, wherein the lower baud rate is less than the second baud rate; and send a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the lower baud rate.

4 . The device of claim 2 , wherein the at least one processor is further configured to:
receive a data frame from at least one device coupled to the CAN bus; determine, in response to receiving the data frame, that the CAN bus supports the second baud rate based on an error count of the CAN controller; determine a higher baud rate, wherein the higher baud rate is greater than the second baud rate; and send a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the higher baud rate.

5 . The device of claim 2 , wherein the at least one processor is further to configured to:
receive a data frame from at least one device coupled to the CAN bus; determine, in response to receiving the data frame, that a CAN device coupled to the CAN bus does not support the second baud rate; and operate the CAN controller at the first baud rate.

6 . The device of claim 1 , wherein the at least one processor is further configured to:
determine that a first timeout has occurred; and switch, based on the first timeout, to a client mode.

7 . The device of claim 6 , wherein the at least one processor is further configured to send at least one test data frame via the CAN bus, wherein the at least one test data frame includes a pattern of bytes causing the CAN bus to be signaled at a high frequency.

8 . The device of claim 6 , wherein the at least one processor is further configured to:
receive a baud rate change request from a device coupled to the CAN bus, wherein the baud rate change request includes at least one identifier of a new baud rate; determine if the new baud rate is supported by the CAN controller; and send a negative acknowledgement via the CAN bus if the new baud rate is not supported by the CAN controller.

9 . A computer-implemented method of selecting baud rates using a computer, the computer including a memory, a Controller Area Network (CAN) controller coupled to a CAN bus, and at least one processor coupled to the CAN controller and the memory, the method comprising:
setting the CAN controller to a first baud rate; determining a second baud rate; and sending, in response to determining the second baud rate, a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the second baud rate.

10 . The method of claim 9 , further comprising:
determining a timeout has elapsed; sending, in response to determining the timeout has elapsed, a baud rate confirmation request via the CAN bus; and setting the CAN controller to the second baud rate.

11 . The method of claim 10 , further comprising:
receiving a data frame from at least one device coupled to the CAN bus; determining, in response to receiving the data frame, that the CAN bus does not support the second baud rate based on an error count of the CAN controller; determining a lower baud rate, the lower baud rate being less than the second baud rate; and sending a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the lower baud rate.

12 . The method of claim 10 , further comprising:
receiving a data frame from at least one device coupled to the CAN bus; determining, in response to receiving the data frame, that the CAN bus supports the second baud rate based on an error count of the CAN controller; determining a higher baud rate, the higher baud rate being greater than the second baud rate; and sending a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the higher baud rate.

13 . The method of claim 10 , further comprising:
receiving a data frame from at least one device coupled to the CAN bus; determining, in response to receiving the data frame, that a CAN device coupled to the CAN bus does not support the second baud rate; and operating the CAN controller at the first baud rate.

14 . The method of claim 9 , further comprising:
determining a first timeout has occurred; and switching, based on the first timeout, to a client mode.

15 . The method of claim 14 , further comprising sending at least one test data frame via the CAN bus, wherein the at least one test data frame includes a pattern of bytes causing the CAN bus to be signaled at a high frequency.

16 . The method of claim 14 , further comprising:
receiving a baud rate change request via the CAN bus, wherein the baud rate change request includes at least one identifier of a new baud rate; determining if the new baud rate is supported by the CAN controller; and sending a negative acknowledgement via the CAN bus if the new baud rate is not supported by the CAN controller.

17 . A non-transitory computer readable medium having stored thereon sequences of instruction instructions for selecting baud rates for a device coupled to a Controller Area Network (CAN) bus, the instructions causing at least one processor to:
set a CAN controller to a first baud rate; determine a second baud rate; and send, in response to determining the second baud rate, a baud rate change request via the CAN bus, wherein the baud rate change request includes at least an identifier of the second baud rate.

18 . The non-transitory computer readable medium according to claim 17 , wherein the sequences of instructions include instructions that cause the at least one processor to:
determine a timeout has elapsed; send, in response to determining the timeout has elapsed, a baud rate confirmation request via the CAN bus; and set the CAN controller to the second baud rate.

19 . The non-transitory computer readable medium according to claim 18 , wherein the sequences of instructions include instructions that cause the at least one processor to:
receive a data frame from at least one device coupled to the CAN bus; determine, in response to receiving the data frame, that the CAN bus does not support the second baud rate based on an error count of the CAN controller; determine a lower baud rate, wherein the lower baud rate is less than the second baud rate; and send a baud rate change request via

Assignees

• Schneider Electric It Corp

Inventors

• Andrews Bibin

Classifications

• H04L2012/40215

  Controller Area Network CAN · CPC title

• H04L69/28

  Timers or timing mechanisms used in protocols · CPC title

• H04L5/0055

  Physical resource allocation for ACK/NACK (for physical mapping arrangements in ARQ protocols H04L1/1861) · CPC title

• H04L12/4013 Primary

  Management of data rate on the bus (systems modifying transmission characteristics according to link quality H04L1/0001) · CPC title

• H04L2012/40273

  the transportation system being a vehicle · CPC title