device and measuring method for ascertaining the internal delay time of a can bus connection unit

Patent metadata

Field	Value
Publication number	US-2016173295-A1
Application number	US-201414902623-A
Country	US
Kind code	A1
Filing date	Jun 11, 2014
Priority date	Jul 4, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

A device is provided for ascertaining the internal delay time of a CAN bus connection unit in a bus system including user stations exchanging messages via a bus, the transmission access to the bus for each message being assigned using an arbitration method according to CAN standard ISO 11898-1 to one user station which becomes the transmitter for this message. The device includes a unit for ascertaining the internal delay time using one of (i) a delay counter for ascertaining the delay time between a transmission signal and a reception signal, the delay counter being stopped if the reception signal has a dominant level and the counter content of the delay counter is greater than/equal to a predefined configuration value, or (ii) the maximum and minimum delay times of the bus connection unit.

First claim

1 - 10 . (canceled)

11 . A device for ascertaining an internal delay time of a CAN bus connection unit in order to check a correct function of a serial data transmission in a bus system including at least two user stations which are each connected to a bus via a respective bus connection unit and are able to exchange messages via the bus, the transmission access to the bus for each message being assigned with the aid of the arbitration method according to CAN standard ISO 11898-1 to a selected user station which assumes a transmitter role for the selected message, wherein the device comprises:
a unit for ascertaining the internal delay time one of (i) using a delay counter for ascertaining a delay time between a transmission signal and a reception signal, the delay counter being stopped if the reception signal has a dominant level and a counter content of the delay counter is not less than a predefined configuration value, or (ii) based on maximum and minimum delay times of the bus connection unit.

12 . The device as recited in claim 11 , wherein the minimum delay time is a value which is a function of the predefined configuration value.

13 . The device as recited in claim 11 , wherein a position of an SSP is predefined, at which a comparison of the transmission signal transmitted to a selected bus connection unit with the reception signal received by the selected bus connection unit is carried out.

14 . The device as recited in claim 11 , further comprising:
at least one of: (i) a delay unit configured to generate one of an undelayed transmission signal or a transmission signal delayed by a predetermined time delay; and (ii) a comparison unit configured to compare a transmission signal transmitted to a selected bus connection unit with a reception signal received by the selected bus connection unit, in order to check the correct function of the data transmission during the transmission.

15 . The device as recited in claim 14 , further comprising:
a switching unit configured to selectively switch between the undelayed transmission signal and the transmission signal delayed by a predetermined time delay, so that the comparison unit is able to selectively use one of the undelayed transmission signal or the transmission signal delayed by the predetermined time delay for checking the correct function of the data transmission.

16 . A measuring method for ascertaining an internal delay time of a CAN bus connection unit in order to check a correct function of a serial data transmission in a bus system including at least two user stations which are each connected to a bus via a respective bus connection unit and are able to exchange messages via a bus, the transmission access to the bus for each message being assigned with the aid of the arbitration method according to CAN standard ISO 11898-1 to a selected user station which assumes a transmitter role for the selected message, the method comprising:
ascertaining the internal delay time one of (i) using a delay counter for ascertaining a delay time between a transmission signal and a reception signal, the delay counter being stopped if the reception signal has a dominant level and a counter content of the delay counter is not less than a predefined configuration value, or (ii) based on maximum and minimum delay times of the bus connection unit.

17 . The measuring method as recited in claim 16 , wherein the minimum delay time is a value which is a function of the predefined configuration value.

18 . The measuring method as recited in claim 16 , wherein a position of an SSP is predefined, at which a comparison of the transmission signal transmitted to a selected bus connection unit with the reception signal received by the selected bus connection unit is carried out.

19 . The measuring method as recited in claim 16 , further comprising:
at least one of: (i) generating, by a delay unit, one of an undelayed transmission signal or a transmission signal delayed by a predetermined time delay; and (ii) comparing, by a comparison unit, a transmission signal transmitted to a selected bus connection unit with a reception signal received by the selected bus connection unit, in order to check the correct function of the data transmission during the transmission.

20 . The measuring method as recited in claim 19 , further comprising:
selectively switching, by a switching unit, between the undelayed transmission signal and the transmission signal delayed by a predetermined time delay, so that during the step of comparing, the comparison unit is able to selectively use one of the undelayed transmission signal or the transmission signal delayed by the predetermined time delay for checking the correct function of the data transmission.

Assignees

• Bosch Gmbh Robert

Inventors

• Hartwich Florian

Classifications

• H04L7/0041

  Delay of data signal · CPC title

• H04L2012/40215

  Controller Area Network CAN · CPC title

• H04L43/0852

  Delays · CPC title

• H04L12/4135 Primary

  using bit-wise arbitration · CPC title