DE102011051758A1 - Controller area network bus adapter for connecting to controller area network bus of motor vehicle, has intermediate storage formed to store controller area network bus data according to first-in-first-out principle, if necessary - Google Patents

Abstract

The Controller area networkbus adapter (1) has an interface (3,3') for connection with a controller area network-bus of a motor vehicle, and another interface (5) for wireless or wired connection with a computer. An intermediate storage (9) is formed to store controller area network bus data according to first-in-first-out principle, if necessary. The controller area network bus data is received from the former interface. The latter interface is provided as a Universal serial bus-interface.

Description

The invention relates to a CAN bus adapter for connection to the CAN bus of a motor vehicle according to the preamble of claim 1.

CAN bus adapters of the type discussed here are known in principle. They serve, in particular, to receive data, in particular measurement data, from the CAN bus of a motor vehicle and to convert them in such a way that they can be received and processed by a computer or the like computing device connected to the CAN bus adapter. A computer connected to the CAN bus adapter preferably has a suitable computer program which is suitable for processing and / or graphing the received CAN bus data. Preferably, it is also possible to transfer data from the computer via the CAN bus adapter to the CAN bus, in particular, for example, to make modifications to control devices or the like. The CAN bus adapter typically includes a microcontroller that captures the CAN bus data and processes or converts it so that it can be read out via an interface that can be connected to a computer or similar device. This interface is usually a USB interface that connects the computer to the CAN bus adapter. It is understood that additionally or alternatively, other interfaces, in particular also wireless interfaces for connecting the CAN bus adapter with a computer or similar computing device can be provided.

In the conventional CAN bus adapters, the problem arises that received CAN bus data, in particular measurement data, irrevocably lost if, for example, a computer connected to the CAN bus adapter intentionally or unintentionally during the read operation of the CAN bus Adapter is disconnected. In this case, a measurement to be made must be carried out again or the read-out process restarted, which entails a considerable workload and consequently leads to productivity losses. For this reason, in the known CAN bus adapters, it is necessary that the entire read-out operation be performed under the supervision of a user.

The object of the present invention is therefore to provide a CAN bus adapter for connection to the CAN bus of a motor vehicle, which avoids data loss when a computer connected to the CAN bus adapter or the like fails, that is H. In particular, it is switched off, restarted or removed and, in addition, operates safely and reliably without the need for supervision by a supervisor.

To solve the above object, a CAN bus adapter with the features of claim 1 is proposed. The CAN bus adapter is used for connection to the CAN bus of a motor vehicle and has at least a first interface for connection to the CAN bus of a motor vehicle and at least a second interface for wireless or wired connection to a computer or the like device. The CAN bus adapter is characterized by at least one intermediate memory which is designed, if required, to receive the CAN bus data received from the at least one first interface according to the first-in-first-out principle, ie. H. to save according to the queuing principle.

An essential point of the invention thus lies in the fact that received CAN bus data are stored in the temporary storage (buffer memory) in the event of a temporary or even prolonged, intentional or unintentional interruption of the read-out process. Characterized in that the data according to the first-in-first-out principle (FIFO), d. H. Thus, after the so-called queuing principle are stored, after reconnecting a computer or the like device automatically those data can be read out first, the first, d. H. most recent in time, were sent from the CAN bus of the motor vehicle. "When needed" means that as soon as the computer has been disconnected from the CAN bus adapter or switched off, the subsequent CAN bus data received by the CAN bus adapter are automatically stored in the buffer memory. When the computer is reconnected or turned on, the buffered data is automatically transferred to the computer in the order of reception, and the readout operation is continued in the usual manner. The CAN bus data received from the CAN bus adapter can be transmitted in the sequence in question to the device connected to the CAN bus adapter in exactly the same order as that used by the CAN Bus adapters were received.

The CAN bus measurements in a motor vehicle are much safer and more reproducible by the CAN bus adapter according to the invention, because errors in the transmission to a computer are almost impossible. In addition, a supervisor can be dispensed with. It is even conceivable that a user will start the read process, then remove the computer from the CAN bus adapter to use it for a different purpose, and only after the read operation has finished the computer connects to the CAN bus adapter. The cached CAN bus data is then transferred to the computer in the correct order automatically, ie without the need for a prompt, acknowledgment or the like by the user.

For a user, the CAN bus adapter proposed here represents purely externally nothing else than a conventional CAN bus adapter, in particular a CAN-to-USB converter, which allows him to different data from the motor vehicle, in particular by means of a appropriate software to visualize. The temporary storage function is preferably implemented in the CAN bus adapter in such a way that the buffering of the CAN bus data and the subsequent resumption of the read-out process run completely unnoticed by the user in the background. This is possible because the function of the buffer is controlled completely automatically.

Thus, in the CAN bus adapter preferably a switching device is provided which detects a removal or shutdown of a data receiving device, such as a computer, preferably in "real time" and immediately caching the data by redirecting the CAN bus data flow in the buffer initiates. The switching device is thus advantageously designed such that it only supplies received CAN bus data to the buffer when no connected and switched-on computer or similar device is recognized ("as required"). However, if a connected and powered on computer is detected, the receiving CAN bus data and possibly cached data in the usual way. The switching device must therefore be designed so that it detects an interruption of a connection between the CAN bus adapter and a connected device and the measurement data received from the CAN bus automatically in the correct order, d. H. So in the order received (FIFO principle) stores in the buffer. In the present case, when referring to a computer as a receiving or reading device for the CAN bus data, it should be understood that this is not to be understood as a restriction. Rather, it is crucial that the receiving device is suitable for evaluation and, if appropriate, visual presentation.

As said, the second interface is provided in particular for wireless or wired connection to a computer or similar device. The second interface can be designed for example as a USB interface. Furthermore, it is also conceivable to provide a plurality of second interfaces, wherein preferably several different interfaces are provided for connection to one or more computers. Furthermore, it is conceivable additionally or alternatively to provide a WLAN connection as the second interface.

In addition to the buffer memory, which receives the received CAN bus data when required, namely, in particular when the connection of the CAN bus adapter and a computer or similar device is interrupted, a further memory device may be provided, however, as long-term memory. Memory device is formed. This memory device thus serves for the continuous detection of received CAN bus data. In this way, it enables the storage of the received CAN bus data according to selected parameters in so-called "sessions". The sessions can be defined by a user, for example by means of date, time, number range, etc. This allows the user to restore a complete session if needed. It is thus not a short-term memory, but a long-term memory, and must therefore have a corresponding storage capacity.

The buffer can be configured either as an external or internal memory device. For example, it is conceivable to provide an integrated flash or SD memory card. However, it is also possible to provide corresponding recording areas for external flash or SD memory cards. It is also conceivable, in particular, to form an internal buffer by means of a micro-SD memory device.

Particularly preferred is a CAN bus adapter on which a suitable computer program (software) for displaying and processing the existing CAN bus data is stored on a connected computer. The computer program is preferably after the connection of a computer fully automatically transferable and executable on this, unless the program is already stored on the connected computer. The CAN bus adapter is thus designed so that it detects when a connected computer does not have a suitable computer program for the evaluation and visualization of the received CAN bus data. In this case, the required computer program is automatically installed and started on the connected computer. At best, this requires confirmation from the user. In this way, any computer, in particular PC can be connected to the CAN bus adapter, even if a computer program for reading the CAN bus data is not installed on it. By doing the installation of the Program is done automatically, an installation effort is avoided by the user. In this way, the CAN bus adapter can be used very flexibly and is ready for immediate use.

The invention will be explained in more detail below with reference to the drawing. Show it:

1 a schematic representation of a CAN bus adapter according to the invention, and

2 a schematic diagram of the CAN bus adapter 1 according to the invention.

1 shows a schematic representation of a CAN bus adapter 1 with two first interfaces 3 and 3 ' for connection to one or more in the figure not recognizable CAN buses of a motor vehicle. When data over the first interfaces 3 . 3 ' to the CAN bus adapter 1 are sent, they serve as an input interface. However, it is also possible to use data via the interfaces 3 . 3 ' to the CAN bus, which then act as the output interface. The CAN bus adapter 1 also includes a second interface 5 for connection to a computer not shown in the figure or the like device for receiving the CAN bus data. As already mentioned in the introduction, several wireless and / or wired interfaces can also be used 5 be provided for connection to one or more read-out devices.

In the following, only one computer will be referred to as a connected reader. It is understood that the computer may be, in particular, a notebook, netbook, PC, personal digital assistant or the like. All that matters is that the data can be processed and visualized on the reading device connected to the CAN bus adapter, in particular by means of suitable software.

The CAN bus adapter 1 also includes an interface 6 , in particular an Ethernet interface, which is used to configure the CAN bus adapter 1 can serve. Furthermore, here is an example of an additional WLAN interface 7 provided, which may be designed to connect to the CAN bus either as a first interface or for connection to a computer or the like device as a second interface.

The CAN bus adapter comprises two memory devices in the present embodiment 9 and 11 , which may be formed for example as SD memory or as flash memory or the like internal or external memory. In addition, the storage capacities of the storage devices 9 and 11 adapted to the respective use. For example, it is conceivable to provide storage devices with storage capacities of 4 GB, 8 GB or even 16 GB.

The storage device 9 For example, it may constitute the buffer according to the present invention which stores CAN bus data according to the FIFO principle when needed. in contrast, the storage device 11 serve as a long-term memory with a correspondingly higher storage capacity, which is designed for the continuous storage of CAN bus data in the form of "sessions". The definition of a session can preferably be made by the user via the connected computer. For this purpose, the necessary computer program for reading out the data preferably has a corresponding function. Through the long-term storage device 11 In addition, the CAN bus adapter assumes the additional function of a hard disk, so that other computers can also access the long-term storage device 11 stored CAN bus data.

The CAN bus adapter 1 also includes a microcontroller 13 that's about the first interfaces 3 . 3 ' received CAN bus data received, processed and in a suitable data format to the second interface 5 transmitted. The CAN bus adapter 1 also includes a power supply device 15 over a line 17 can be supplied with voltages in the range of 9 volts to 36 volts. However, it is also conceivable to supply energy, in particular via the USB connection of a connected computer. It is also conceivable to supply the CAN bus adapter with energy via the CAN bus. Furthermore, it is preferably possible to switch between different energy sources. If, for example, a connected computer is removed, the power supply of the CAN bus adapter for buffering CAN bus data must continue to be guaranteed. This can be done, for example, via an external power supply or a supply via the CAN bus of a motor vehicle.

As I said, it is not only possible data, in particular measurement data, from the CAN bus of a motor vehicle via the CAN bus adapter 1 read. Rather, it is also possible configuration data or the like from a computer using the microcontroller 13 into CAN bus data and over the interfaces 3 respectively. 3 ' supply the CAN bus of a motor vehicle.

The CAN bus adapter 1 can also have a lighting device 19 feature the state of the CAN bus adapter 1 especially with the help of different colored LEDs can display. For example, a bright reasons LED indicates read-out of CAN bus data while a red LED indicates a malfunction. By contrast, a yellow LED could indicate the supply of data to the CAN bus.

As said, preferably one of the memory devices 9 or 11 adapted to act as a buffer, which, if necessary, from the at least one first interface 3 respectively. 3 ' received CAN bus data according to the first-in-first-out principle, ie according to the principle of the queue stores. So if there is a connection between the interface 5 and a connected computer is interrupted, those from the interfaces 3 respectively. 3 ' received CAN bus data through the memory device 9 logged in the correct order. After completion of the interruption, the data can then simply be removed from the storage device by the connected computer 9 be read without any loss of data.

The second data storage device 11 can be designed as long-term memory, as mentioned, the permanent on the interfaces 3 respectively. 3 ' received CAN bus data according to certain criteria, such as date, time, etc. stores. In contrast, the cache stores 9 only on demand CAN bus data, whereby the demand automatically by the CAN bus adapter 1 is detected. The cache 9 So only stores CAN bus data as long as these data are not received from a computer or similar device. Therefore, for the cache 9 in principle, a smaller storage capacity necessary than for the long-term storage device 11 ,

2 shows a schematic diagram of the CAN bus adapter 1 , The functionality of the CAN bus adapter 1 is so that the microcontroller 13 over the first interfaces 3 . 3 ' CAN bus data is received. The CAN bus adapter 1 includes a switching device 21 which are the ones from the microcontroller 13 received and converted CAN bus data via the second interface 5 to a connected computer or the like device, as described in the 2 is shown. The switching device 21 In addition, by means of a suitable switch, the CAN bus data to the buffer 9 redirect something through the arrow 23 is indicated. In the cache 9 the CAN bus data are then stored according to the first-in-first-out principle, so that the last stored data are also read last.

The switching device 21 preferably detects if a computer is connected and ready to use. This is the case when the CAN bus adapter can communicate with suitable software. In this case, the CAN bus data is sent to the computer. However, if a connected computer is turned off or removed, or no computer has been connected, and consequently no communication with the required software is possible, this detects the switching device 21 and automatically forwards the CAN bus data to the buffer, where it is stored according to the FIFO principle.

Furthermore, those of the microcontroller 13 forwarded CAN bus data not only to the switching device 21 but preferably parallel to the second long-term storage device 11 so that the long-term storage device 11 a continuous stream of data from the microcontroller 13 receives.

Overall, the inventive CAN bus adapter behaves like a normal CAN-to-USB converter, which allows him to visualize various data from the motor vehicle with a suitable software. However, in addition to the direct and direct data transmission, the CAN bus adapter (data logger) according to the invention offers further advantages. On the one hand, the device offers a first-in-first-out memory for short-term, intentional or unwanted interruptions. These interruptions are directly linked to the current measurement. That is, if the user has the connection between the CAN bus adapter 1 and a connected computer on which appropriate software is installed, for example due to a PC restart, the CAN bus adapter records the data in its internal temporary storage device at short notice 9 on. Furthermore, it sends this stored data in the background when the software is restarted. The user thus gets the impression that the measurement has continued without interruption, which is from the point of view of the CAN bus adapter 1 also the case is. Thus, only the visualization realized by the software is restarted and not the entire measurement.

Overall, the CAN bus adapter according to the present invention provides a reliable data transmission and data backup, which does not lead to the loss of data or even to a restart of the measurement even in the case of an interruption between the CAN bus adapter and a connected computer, but rather, upon completion of the interruption, the cached data is unsolicited, d. H. automatically transferred to the computer.

LIST OF REFERENCE NUMBERS

1

CAN-bus adapter

3, 3 '

first interfaces

5

second interface

6

Ethernet interface

7

WLAN interface

9

memory device

11

memory device

13

microcontroller

15

Power supply means

17

management

19

lighting device

21

switchover

23

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Claims (11)

CAN bus adapter ( 1 ) for connection to the CAN bus of a motor vehicle, comprising at least a first interface ( 3 . 3 ' ) for connection to the CAN bus of a motor vehicle, and at least one second interface ( 5 ) for wireless or wired connection to a computer or similar device, characterized by at least one intermediate memory ( 9 ) which is adapted, if necessary, from the at least one first interface ( 3 . 3 ' ) to store received CAN bus data according to the first-in-first-out principle. CAN bus adapter according to claim 1, characterized in that a switching device ( 21 ) is provided, which is designed so that it is the buffer memory (if necessary) ( 9 ) Feeds CAN bus data when the connection to the at least one second interface ( 5 ) is interrupted, and otherwise the received CAN bus data to the at least one second interface ( 5 ) connected computer or the like device. CAN bus adapter according to claim 2, characterized in that the switching device ( 21 ) cooperates with a computer program which is connected to the at least one second interface ( 5 ) connected computer or the like device is stored. CAN bus adapter according to claim 1 or 2, characterized in that the at least one second interface ( 5 ) is a USB interface. CAN bus adapter according to one of the preceding claims 1 to 3, characterized in that for the configuration of the CAN bus adapter ( 1 ) another interface ( 6 ), in particular an Ethernet interface is provided. CAN bus adapter according to one of the preceding claims, characterized in that a long-term storage device ( 11 ) for storing the at least one first interface ( 3 . 3 ' ) received data is provided. CAN bus adapter according to one of the preceding claims, characterized in that the memory device ( 11 ) is arranged and arranged such that it receives the information from the at least one first interface ( 3 . 3 ' ) continuously stores received data. CAN bus adapter according to one of the preceding claims, characterized in that at least one receiving area for an external memory device, in particular for a flash or SD memory card, is provided. CAN bus adapter according to one of the preceding claims, characterized in that the temporary storage ( 9 ) is designed as an internal memory device, in particular as a micro-SD memory device. CAN bus adapter according to one of the preceding claims, characterized in that it comprises a software program for displaying and processing the received CAN bus data on one of the at least one second interface ( 5 ) connected computer or the like device. CAN bus adapter according to one of the preceding claims, characterized in that the software program after the connection of a computer or the like device is preferably automatically installable and executable on this or on this.

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