WO2016128238A1

WO2016128238A1 - Subscriber station for a bus system, and method for operating a bus system with subscriber stations for different data transmission standards

Info

Publication number: WO2016128238A1
Application number: PCT/EP2016/052029
Authority: WO
Inventors: Florian Hartwich
Original assignee: Robert Bosch Gmbh
Priority date: 2015-02-09
Filing date: 2016-02-01
Publication date: 2016-08-18
Also published as: DE102015202242A1

Abstract

A subscriber station (20; 30; 200; 300) for a bus system (1) and a method for operating a bus system with subscriber stations (10, 20, 30; 100, 200, 300) for different data transmission standards are provided. The subscriber station (20; 30; 200; 300) comprises a transmission/reception device (22; 32; 220; 320) for sending a message (4; 5; 6; 7; 8; 9) to/from at least one further subscriber station of the bus system (1; 2), in which exclusive, collision-free access by a subscriber station (10, 20, 30; 100, 200, 300) to a bus line (3) of the bus system (1; 2) is ensured at least intermittently, wherein the transmission/reception device (22; 32; 220; 320) is designed, prior to sending the message (4; 5; 6; 7; 8; 9), to perform an arbitration up to and including a predetermined bit that is arranged after a message field (base-ID; ID-ext) that is provided in the message (4; 5; 6; 7; 8; 9) for the purpose of setting up the intermittent exclusive, collision-free access by a subscriber station (10, 20, 30; 100, 200, 300) to the bus line (3).

Description

Description title

Subscriber station for a bus system and method for operating a

Bus system with subscriber stations for different

Since transmission standards rds

Technical area

The present invention relates to a subscriber station for a bus system and to a method for operating a bus system with subscriber stations for different data transmission standards.

State of the art

The CAN bus system has gained wide acceptance for communication between sensors and ECUs, for example in automobiles. In the CAN bus system, messages are transmitted using the CAN protocol, as described in IS011898. In particular, automotive bus systems are continually evolving toward higher bandwidth, lower latency, and more rigorous real-time capability. More recently, techniques have been proposed for this, such as CAN FD, in which messages conforming to the specification "CAN with Flexible Data Rate,

Specification Version 1.0 "(Source http://www.semiconductors.bosch.de) or according to the IS011898-1 be transmitted, etc. In such techniques, the maximum possible data rate by using a higher timing in the field of data fields over a value Such messages are also referred to as CAN FD frames or CAN FD messages in the following: With CAN FD, the user data length is increased from 8 to 64 bytes and the data transmission rates are significantly higher than with CAN. The extension of the CAN protocol or CAN standard has been extended in addition to primarily functional additions, such as TTCAN, recently with CAN FD especially in terms of the possible (higher) data rate and the usable data packet size, with the very own CAN properties particularly in form the arbitration were received.

With the gradual introduction of CAN FD in existing CAN bus systems, there will be mixed networks or bus systems from existing Classic CAN subscriber stations and new CAN FD subscriber stations. The introduction of new CAN FD subscriber stations into these existing CAN bus systems is facilitated if these new CAN FD subscriber stations for the transmission of CAN FD messages (CAN FD frames) can also be assigned identifiers that have previously been used for Classic CAN messages ( Classic CAN frames) or Classic CAN subscriber stations have been assigned. The reason for this is that it can otherwise occur in extensive bus systems that no free identifier with the desired send priority is available. This also applies if the Classic CAN subscriber stations are equipped with "CAN FD Shield Transceivers" which keep the part of the CAN FD message coming after the FDF bit away from the Classic CAN subscriber stations.

If identical identifiers are assigned in mixed networks or bus systems with Classic CAN subscriber stations and CAN FD subscriber stations, the following case can occur. Possibly a CAN Classic subscriber station or its transmitting / receiving device, which is also called a transmitter, attempts to transmit a Classic CAN message, whereby at the same time a CAN FD subscriber station or its transmitting / receiving device attempts to transmit a CAN FD message the same identifier as the identifier of the Classic CAN message.

This raises the problem that the transceiver which sends a recessive bit but instead sees a dominant bit on the CAN bus will detect a bit error. The bit error then results in sending an error message (Error Frame) and the message being sent destroyed. This would be in this case, neither of the two mentioned

Subscriber stations successful and the transmission on the bus is disturbed.

Disclosure of the invention

It is therefore an object of the present invention to provide a subscriber station for a bus system and a method for operating a bus system

Provide subscriber stations for different data transmission standards, which solve the aforementioned problems. In particular, a subscriber station for a bus system and a method for operating a bus system with subscriber stations for different

Data transmission standards are provided in which the installation and operation of the bus system is simplified without a transmission conflict occurs during operation.

The object is achieved by a subscriber station for a bus system with the features of claim 1. The subscriber station comprises a transmitting / receiving device for transmitting a message to / from at least one further subscriber station of the bus system, in which at least temporarily an exclusive, collision-free access of a subscriber station to a bus line of the bus system is ensured, wherein the transmission / Receiving device is designed before sending the message to perform an arbitration up to and including a predetermined bit, which after a

Message field is provided, which is provided in the message for establishing the temporary exclusive, collision-free access of a subscriber station to the bus line.

With the subscriber station, even if two transceivers simultaneously attempt to send a Classic CAN message and a CAN FD message with the same identifier, neither message will be destroyed by an error message. For the reasons mentioned above, this is particularly helpful in the transition phase in the gradual introduction of CAN FD in mixed bus systems from Classic CAN subscriber stations and CAN FD subscriber stations. The procedure performed by the subscriber station can be subsequently inserted into the CAN FD protocol. For example, the insertion is also possible as an option, which is optionally installed.

Advantageous further embodiments of the subscriber station are specified in the dependent claims.

The predetermined bit may be the FDF bit and / or the RRS bit of a CAN FD message.

The subscriber station may also have one

Communication control device for creating a first and / or second message whose data transmission standard differ, wherein the maximum possible data rate of the second message by using a higher clocking in the field of data fields is greater than a maximum possible data rate of the first message.

In this case, the first message may be a Classic CAN message with a basic format or a Classic CAN message with an extended format and the second message may be a CAN FD message with a basic format or a CAN FD message with an extended format.

It is possible that the transmitting / receiving device is configured to transmit or receive the first and / or second message.

In one embodiment, the transmitting / receiving device may be configured to optionally send the RRS bit recessively different from the CAN protocol. In this case, it is possible to send the RRS bit recessively from the ISO standard, or when the FDF bit in the CAN FD format was sent recessively, but it appears dominant on the bus line to give up the arbitration.

The transmitting / receiving device can also be configured to transmit the FDF bit dominant in the case of a CAN message and to send the FDF bit recessively in the case of a CAN FD message. In a further refinement, it is possible for the transmitting / receiving device to transmit the IDE bit dominant in the case of a basic-format Classic CAN message, and / or to recessively send the SSR bit and the IDE bit in the case of a Classic CAN message with an extended format and the rO-bit is dominant, and / or the RRS bit, the IDE bit, and the res bit are dominant in a basic format CAN FD message, and / or the SRR is a wider format CAN FD message Bit and the IDE bit is recessive and sends the RRS bit and the res bit dominant.

The subscriber station described above may be part of a bus system, which also comprises a parallel bus line and at least two subscriber stations, which are connected to one another via the bus line so that they can communicate with each other. In this case, at least one of the at least two subscriber stations is a subscriber station described above.

The aforementioned object is also achieved by a method for operating a bus system with subscriber stations for different ones

Data transmission standards according to claim 10 solved. In the method, a transmitting / receiving device sends a message to / from at least one further subscriber station of the bus system, in which an exclusive, collision-free access of a subscriber station to a bus line of the bus system is ensured at least temporarily, the method comprising the step : Performing an Arbitration Up to and including One

predetermined bit, which is arranged after a message field (base-ID; ID-ext), which is provided in the message for establishing the temporary exclusive, collision-free access of a subscriber station to the bus line.

The method offers the same advantages as previously described in relation to the

Subscriber station are called.

Further possible implementations of the invention also include not explicitly mentioned combinations of before or below with respect to the

Embodiments described features or embodiments. there The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

drawings

The invention is described in more detail below with reference to the accompanying drawings and to exemplary embodiments. Show it:

1 is a simplified block diagram of a bus system according to a first embodiment;

FIG. 2 is an illustration of a structure of a first message in the bus system according to the first embodiment; FIG.

FIGS. 3 and 4 each show an illustration of a structure of a first and second variant of a second message in the bus system according to the first embodiment;

5 is a simplified block diagram of a bus system according to a second embodiment;

6 is an illustration of a structure of a first message in the bus system according to a second embodiment;

FIGS. 7 and 8 each show an illustration of a structure of a first and second variant of a second message in the bus system according to the second embodiment; and

In the figures, identical or functionally identical elements are provided with the same reference numerals, unless stated otherwise.

Description of the embodiments

1 shows a bus system 1, which may be, for example, a CAN bus system, a CAN FD bus system, etc. The bus system 1 can be in a vehicle especially a motor vehicle, an airplane, etc., or in the hospital, etc. find use.

In Fig. 1, the bus system 1 has a bus line 3, to which a plurality of subscriber stations 10, 20, 30 are connected. Messages 4, 5, 6 in the form of signals between the individual subscriber stations 10, 20, 30 can be transmitted via the bus line 3. The subscriber stations 10, 20, 30 may be, for example, control devices, sensors, display devices, etc. of a motor vehicle.

As shown in Fig. 1, the subscriber station 10 has a

Communication control device 11 and a transmitting / receiving device 12. The subscriber station 20, however, has a communication control device 21 and a transmitting / receiving device 22. The subscriber station 30 has a communication control device 31 and a transmitting / receiving device 32nd

The transmitting / receiving devices 12, 22, 32 of the subscriber stations 10, 20, 30 are each directly connected to the bus line 3, even if this is not shown in Fig. 1. The communication control devices 11, 21, 31 each serve to control a communication of the respective subscriber station 10, 20, 30 via the bus line 3 with another subscriber station of the subscriber stations 10, 20, 30 connected to the bus line 3. The communication control device 11 may be like a conventional CAN -

Controller be executed. The communication control device 11 creates and reads first messages 4, for example Classic CAN messages 4. The Classic CAN messages 4 are constructed in accordance with the Classic basic format in which a number of up to 8 data bytes may be included in the message 4, as shown in FIG 2.

The communication controller 21 in FIG. 1 may be implemented like a conventional CAN FD controller. The communication control device 21 generates and reads second messages 5 or 6, for example CAN FD messages 5, 6. Here, the CAN FD messages 5 are connected to the CAN FD message. Basic format constructed in a first variant in which in the message 5, a number of up to 16 bytes of data may be included, as shown in Fig. 3. The CAN FD messages 6 are constructed with the CAN FD basic format in a second variant in which a number of 20 to 64 data bytes may be included in the message 6, as shown in FIG.

The communication controller 31 may be configured to provide or receive, as needed, a Classic CAN message 4 or a CAN FD message 5, 6 for the transceiver 32. The communication control device 21 thus creates and reads a first message 4 or second message 5, 6, the first and second messages 4, 5, 6 differing by their data transmission standard, namely CAN or CAN FD in this case.

The transceiver 12 may be like a conventional CAN

Transceiver be executed. The transceiver 22 may be implemented like a conventional CAN FD transceiver. The transceiver 32 may be configured to provide or receive messages 4 according to the current CAN base format or messages 5, 6 according to the current CAN FD basic format for the communication controller 31 as needed

With the two subscriber stations 20, 30 can be a formation and then

Transmission of messages 5, 6 with CAN FD or higher

Data rates can be realized as CAN FD.

2 shows a message 4 sent by the subscriber station 10 in the Classic CAN basic format. The message 4 has an SO F bit 41 and several

Message fields, such as an arbitration field 42, a control field 43, a data field 44 and a checksum field 45 (CRC field). The arbitration field 42 comprises an identifier of the message 4 in the base ID field. At the end of the arbitration field 42, an RTR bit is arranged. The control field 43 starts with an IDE bit, followed by an FDF bit followed by a DLC field. The data field 44 is absent if the DLC field is 0 or the RTR bit is recessive is sent. The checksum field 45 contains a CRC checksum in a CRC-seq field and ends with a subsequent CRC delimiter CRC-Del. The fields and bits mentioned are known from ISO-CD-11898-1 and are therefore not described here in detail.

In FIG. 2, dominant bits are shown with a wide line at the bottom of the message 4. Recessive bits are shown in FIG. 2 with a broad line at the top of the message 4. As shown in Fig. 2, the

Communication controller 11, the message 4 is created such that the SOF bit, the IDE bit and the FDF bit are dominant, whereas the CRC

Delimiter CRC-Del is recessive. Thus, the transceiver 12 sends the SOF bit, the IDE bit and the FDF bit dominant and the CRC delimiter CRC-Del recessive.

According to the Classic CAN specification and also according to the new CAN FD specification, which includes CAN FD messages, the messages sent in FIG. 2 end the CAN bit arbitration or the arbitration phase 47 at the bit following the last bit of the Identifier comes. Exceptions are stuffing bits (stuff bits). During the arbitration, it is determined which subscriber station of the subscriber stations 10, 20, 30 in the bus system 1 is allowed to transmit to the bus line 3, wherein the transmitting subscriber station of the subscriber stations 10, 20, 30 has an exclusive, collision-free access to the bus line 3 during this time. The arbitration phase 47 is followed by a data phase 48. The data phase 48 is again followed by the arbitration phase 47.

In the Classic CAN message 4 of Fig. 2, the bit after the last bit of the identifier in the base ID field is the RTR bit. The RTR bit is recessive in a remote message (remote frame), not shown, and dominant in a data message (data frame). A dominant RRS or "reserved bit" is transmitted here in CAN FD messages 5, 6. Up to, more precisely according to, the RTR bit or RRS-Bi, there is a transmitting / receiving device (transmitter) of the transceivers 12 , 22, 32, which sends a recessive bit but instead sees a dominant bit on the bus line 3 as a CAN bus, loses the arbitration and becomes the receiver (receiver). 3 shows a message 5 transmitted by the subscriber station 20 or 30 with up to 16 data bytes in the CAN FD basic format. The message 5 has a SOF bit 51 and a plurality of message fields, such as an arbitration field 52, a control field 53, a data field 54 and a data field 54

Checksum field 55 (C RC field). The arbitration field 52 comprises in the base I D field an identifier of the message 5. At the end of the

Arbitration field 52 is an R RS bit arranged. Here, too, begins

Control field 53 with an I DE bit, followed by an FDF bit but followed by a res bit and a subsequent BRS bit and then an ESI bit followed by a DLC field. The data field 54 is not present if the DLC field of the control field 53 has the value 0. The checksum field 55 includes a stuff count field labeled SC, a CRC checksum in a CRC seq field, and ends with a subsequent CRC delimiter CRC-Del. The fields and bits mentioned are known from ISO-CD-11898-1 and are therefore not described here in detail.

In Fig. 3, the length of an arbitration phase 57 in the present

Embodiment indicated. Arbitration phase 57 is followed by data phase 58 if the BRS bit in message 5 is recessive. Thus, the Arbitrationphase 57 lasts longer than previously specified in ISO-CD-11898-1. In other words, the arbitration phase 57 partially comprises the control field 53 or, to put it another way, extends partially into the control field 53.

4 shows a message 6 transmitted by the subscriber station 30 having 20 to 64 data bytes in the CAN FD basic format. The message 6 has a SOF bit 61 and a plurality of message fields, such as an arbitration field 62, a control field 63, a data field 64 and a data field 64

Checksum field 65 (CRC field). The arbitration field 62 comprises an identifier of the message 6 in the base I D field

Data field 64 and the checksum field 65 is the structure of the message 6 same as the structure of the message 5 of Fig. 3. Also, the arbitration phase 67 is equal to the arbitration phase 57 and the data phase 68 is equal to the data phase 58th

As shown in FIGS. 3 and 4, the communication controller 21 or 31 has prepared the messages 5, 6 such that the SOF bit, the R RS bit, the IDE bit and the res bit are dominant, whereas the CRC delimiter CRC-Del is recessive. Thus, the transceivers 22, 32 send the SOF bit, the RRS bit, the IDE bit, and the res bit to be recessive and the CRC delimiter CRC-Del to be recessive. The above-mentioned dominant and recessive bits are also shown in FIG. 3 and FIG. 4, as described with reference to FIG. 2.

The subscriber stations 20, 30 make use of the fact that arbitration phases of all messages are seen by all subscriber stations 10, 20, 30 of the bus system. Consequently, at the subscriber stations 20, 30 for CAN FD messages, the arbitration is up to a predetermined bit, namely until

FDF bit, continued. Thus, the arbitration in the 11-bit identifiers shown in FIG. 2 to FIG. 4 is further continued by 2 bits. The FDF bit is sent recessively in CAN FD messages 5, 6, dominant in Classic CAN messages 4. If a transceiver 21, 31, which wants to transmit a CAN FD message 5 or 6 and has sent the FDF bit recessively, instead sees a dominant bit on the bus, it will lose the arbitration and become the receiver of one Classic CAN message 4, which was sent for example by the subscriber station 10. This option can be called "FDF arbitration".

In a modification of the first exemplary embodiment, the bus system 1 can also have a subscriber station which can only generate and transmit CAN FD messages 5 as well as receive and read. It is additionally or alternatively also possible that the bus system 1 also has a subscriber station which can only generate and transmit CAN FD messages 6 and can also receive and read. In such subscriber stations are the

Communication control device and the transmitting / receiving device constructed accordingly. Fig. 5 shows a bus system 2 according to a second embodiment with

Subscriber stations 100, 200, 300, which are connected to a bus line 3. The subscriber station 100 has a communication control device 110 and a transceiver 120. The subscriber station 200, on the other hand, has a communication control device 210 and a transceiver 220. The subscriber station 300 has a Communication control device 310 and a transmitting / receiving device 320. The transmission / reception devices 120, 220, 320 of the

Subscriber stations 100, 200, 300 are each directly connected to the bus line 3, although this is not shown in Fig. 5. The

Subscriber stations 100, 200, 300 are implemented except for the following differences as described in the first embodiment.

Subscriber station 100 transmits first messages 7, which is, for example, a Classic Extended Message Format CAN message, as shown in FIG. Subscriber station 200 transmits second messages 8, which may be, for example, a first variant of an extended format CAN FD message, which may include a number of up to 16 bytes of data in message 8, as shown in FIG. The subscriber station 200 may alternatively also send messages 9, which is, for example, a CAN FD message in extended format, in which the message 9 may comprise a number of 20 to 64 data bytes, as shown in FIG. The subscriber station 300 can either send messages 7 or 8 or 9.

According to FIG. 6, the message 7 has an SOF bit 71 and several

Message fields, such as an arbitration field 72, a control field 73

(Control field), a data field 74 (Data field) and a checksum field 75 (CRC field). The arbitration field 72 includes in the base ID field and the ID ext field an identifier (identifier) of the message 7. Between the base ID field and the ID ext field are each an SRR bit and an IDF - Bit provided. Arranged at the end of the arbitration field 72 is an RTR bit. The control panel 73 starts with a FDF bit followed by an r0 bit. The data field 74 is not present if the DLC field of the control field 73 is 0 or the RTR bit is recessive. Otherwise, the message 7 is constructed in the same way as the message 4 of FIG. 2 and has a corresponding one

Arbitration phase 77 and data phase 78.

As shown in FIG. 6, the communication controller 110 has created the message 7 such that the SOF bit, the FDF bit, and the r0 bit are dominant, whereas the SRR bit, the IDE bit, and the CRC delimiter CRC-Del is recessive. Thus, the transceiver 12 transmits the SOF bit, the FDF bit and the rO-bit dominant and the SRR bit, the IDE bit and the CRC delimiter CRC-Del recessive.

According to FIG. 7, the message 8 has a SOF bit 81 and several

Message fields, such as an arbitration field 82, a control field 83, a data field 84 and a checksum field 85 (CRC field). The arbitration field 82 includes an identifier (identifier) of the message 8 in the base ID field and the ID ext field. At the end of the arbitration field 82, an RRS bit is arranged. The control field 83 starts with an FDF bit, followed by a res bit, a BRS bit and an ESI bit. The data field 84 is not present if the DLC field of the control field 83 has the value 0. Otherwise, the message 8 is constructed in the same way as the message 5 of FIG. 3 and has a corresponding arbitration phase 87 and data phase 88.

According to FIG. 8, the message 9 has a SOF bit 61 and several

Message fields, such as an arbitration field 92, a control field 93, a data field 94 and a checksum field 95 (CRC field). The arbitration field 92 comprises in the base ID field an identifier (identifier) of the message 9. With difference of the data field 94 and the

Checksum field 95 is the structure of message 9 similar to the structure of message 8 of FIG. 7.

As shown in FIGS. 7 and 8, the communication controller 210 or 310 has prepared the messages 8, 9 so that the SOF bit, the RRS bit, and the res bit are dominant, whereas the SRR bit, the IDE bit, the FDF bit, and the CRC delimiter CRC-Del are recessive. Thus, the transceiver 220, 320 sends the SOF bit, the RRS bit and the res bit dominant, and the SRR bit, the IDE bit, the FDF bit, and the CRC delimiter CRC-Del are recessive. The above-mentioned dominant and recessive bits are also shown in FIGS. 7 and 8, as described with reference to FIG. 2.

Even at the subscriber stations 200, 300, the arbitration continues until the FDF bit for CAN FD messages. Thus, the arbitration in the 29-bit identifiers shown in Figs. 6 to 8 is continued by one bit more than set in the current ISO-CD-11898-1. Also in the present embodiment, the FDF bit is sent recessively in CAN FD messages 8, 9, dominant in Classic CAN messages 7. If a transceiver 210, 310 that wants to send a CAN FD message 8 or 9 and has sent the FDF bit recessively sees a dominant bit on the bus instead, it will lose the arbitration and become the receiver of one Classic CAN message 7, which was sent for example by the subscriber station 100.

According to a third embodiment, in addition to transmitting a CAN FD message 5, 6, 8, 9, the transceiver 220, 320 may have the option of sending the reserved RRS bit dominant in the current CAN or CAN FD standard must be sent recessive. This option may be called "RRS-recessive." In this case, the predetermined bit is the RRS bit, so the arbitration phase 57, 67, 87, 97 lasts longer than previously specified in ISO-CD-11898-1 , the arbitration phase 57, 67, 87, 97 ends with the arbitration field 52, 62, 82, 92.

In a modification of the present embodiment, it is also possible that the RRS bit is interrogated in addition to the FDF bit to determine the result of the arbitration.

All of the previously described embodiments of the bus system 1, 2, the

Subscriber stations 10, 20, 30, 100, 200, 300 and the method may be used individually or in all possible combinations.

In particular, all the features of the previously described

Embodiments and / or their modifications are arbitrarily combined. Additionally or alternatively, in particular the following modifications are conceivable. The bus system 1, 2 described above according to the exemplary embodiments is described on the basis of a bus system based on the CAN protocol. However, the bus system 1, 2 according to the embodiments may also be another type of communication network. It is advantageous, but not necessarily a prerequisite, that in the bus system 1 at least for certain periods of time an exclusive, collision-free access of a Subscriber station 10, 20, 30, 100, 200, 300 is guaranteed to a common channel.

The number and arrangement of subscriber stations 10, 20, 30 in the

Bus system 1 of the first embodiment is arbitrary. In addition, the number and arrangement of the subscriber stations 100, 200, 300 in the bus system 2 of the first embodiment is arbitrary. In particular, the

Subscriber station 20 or 30 in the bus system 1 omitted. In particular, the subscriber stations 200 or 300 in the bus system 2 can be omitted. It is also possible for one or more of the subscriber stations 20 or 30 to be present in the bus system 1. It is also possible for one or more of the subscriber stations 200 or 300 to be present in the bus system 2. Subscriber stations 10, 20, 30, 100, 200, 300 may also be present in the bus system 1.

Claims

claims

1) subscriber station (20; 30; 200; 300) for a bus system (1), with

a transmitting / receiving device (22; 32; 220; 320) for transmitting a message (4; 5; 6; 7; 8; 9) to / from at least one further subscriber station of the bus system (1; 2), in which at least temporarily an exclusive, collision-free access to a

Subscriber station (10, 20, 30, 100, 200, 300) is ensured on a bus line (3) of the bus system (1, 2),

wherein the transceiver means (22; 32; 220; 320) is configured prior to transmitting the message (4; 5; 6; 7; 8; 9) to perform an arbitration up to and including a predetermined bit subsequent to a message field (base ID; ID-ext) arranged in the message (4; 5; 6; 7; 8; 9) for establishing the temporary exclusive, collision-free access of a subscriber station (10, 20, 30; 100, 200, 300) is provided on the bus line (3).

2) subscriber station (20; 30; 200; 300) according to claim 1, wherein the

predetermined bit is the FDF bit and / or the RRS bit of a CAN FD message (5; 6; 8; 9).

3) subscriber station (20; 30; 200; 300) according to claim 1 or 2,

in addition with a communication control device (21; 31; 210; 310) for producing a first and / or second message (4, 5, 6; 7, 8, 9) whose data transmission standards differ,

wherein the maximum possible data rate of the second message by using a higher clocking in the field of data fields is greater than a maximum possible data rate of the first message. A subscriber station (20; 30; 200; 300) according to claim 3, wherein the first message (4; 7) is a standard format Classic CAN message (4) or an extended format Classic CAN message (7) and the second message is a CAN FD message (5; 9) with basic format or a CAN FD message with extended format (6; 9).

The subscriber station (20; 30; 200; 300) of claim 3 or 4, wherein the transceiver means (22; 32) for transmitting or receiving the first and / or second message (4, 5, 6; 7, 8, 9 ) is configured.

The subscriber station (20; 30; 200; 300) of any of the preceding claims, wherein the transceiver (22; 32) is configured to optionally recessively send the RRS bit other than the CAN protocol.

A subscriber station (20; 30; 200; 300) as claimed in any one of the preceding claims, wherein the transceiver means (22; 32) is adapted to dominant transmit the FDF bit in a Classic CAN message and to a CAN FD message to send the FDF bit recessive.

Subscriber station (20; 30; 200; 300) according to one of the preceding claims, wherein the transceiver device (22; 32) is configured,

in a Classic CAN message (4) with basic format to send the IDE bit dominant, and / or

for a Classic Extended Message Format message (7), to send the SSR bit and the IDE bit recessively and to send the rO bit dominant, and / or

in a basic format CAN FD message (5; 6), to transmit the RRS bit, the IDE bit and the res bit dominant, and / or

for an extended format CAN FD message (8; 9), to send the SRR bit and the IDE bit recessively and to send the RRS bit and the res bit dominant. Bus system (1; 2), with

a parallel bus line (3), and

at least two subscriber stations (10; 20; 30; 100; 200; 300), which are connected to one another via the bus line (3) such that they can communicate with one another,

wherein at least one of the at least two subscriber stations (10; 20; 30; 100; 200; 300) is a subscriber station (20; 30; 200; 300) according to one of the preceding claims.

Method for operating a bus system with subscriber stations (10, 20, 30, 100, 200, 300) for different ones

Data transmission standards in which a transceiver device (22; 32; 220; 320) transmits a message (4; 5; 6; 7; 8; 9) to / from at least one additional subscriber station (10, 20, 30 100, 200, 300) of the bus system (1, 2), in which an exclusive, collision-free access of a subscriber station (10, 20, 30, 100, 200, 300) to a bus line (3) of the bus system (1 2), the method comprising the step of:

Performing an arbitration up to and including a predetermined bit arranged after a message field (base-ID; ID-ext) included in the message (4; 5; 6; 7; 8; 9) for establishing the temporary exclusive, collision-free one Access one

Subscriber station (10, 20, 30, 100, 200, 300) is provided on the bus line (3).