DE102022205336A1 - Transmitter/receiver device and method for receiving differential signals in a serial bus system - Google Patents

Abstract

A transmitter/receiver device (22; 220; 2200) and a method for receiving differential signals (CAN_H, CAN_L) in a serial bus system (1) are provided. The transmitting/receiving device (22; 220; 2200) has a transmitting module (221) for sending a digital transmission signal (TxD) of a communication control device (22) as an analog differential signal (CAN_H, CAN_L) according to a first operating mode (SIC) onto a bus (40) of the bus system (1) in order to send a message (46) to at least one other subscriber station (10; 20; 30) of the bus system (1), a reception module (222; 2220) for receiving signals (CAN_H, CAN_L ) from the bus (40) and for generating a digital reception signal (RxD) from the analog differential signal (CAN_H, CAN_L) according to the first operating mode (SIC) using a predetermined first reception threshold (T1), and a reception mode setting module (25 ; 250; 2500) for setting the operating mode (SIC; FAST_RX) of the reception module (222; 2220), so that the reception module (222; 2220) receives a digital reception signal (RxD) from the analog differential signal (CAN_H, CAN_L) according to the first Operating mode (SIC) and / or an analog differential signal (CAN_H, CAN_L), which was generated according to a second operating mode (FAST_TX), with which at least one other subscriber station (10; 20; 30) of the bus system (1) sends signals (CAN_H, CAN_L) to the bus (40), the reception mode setting module (25; 250; 2500) being connected between the reception module (222; 2220) and a connection (RXD) for outputting the digital received signal (RxD) is connected to the communication control device (22).

Description

The present invention relates to a transmitting/receiving device and a method for receiving differential signals in a serial bus system. The bus system uses transmitting/receiving devices (transceivers) which are designed to send and receive data at different speeds in the bus system.

State of the art

Serial bus systems are used for message or data transmission in technical systems. For example, a serial bus system can enable communication between sensors and control devices in a vehicle or a technical production system, etc. There are various standards or data transmission protocols for data transmission. In particular, a CAN bus system, an LVDS bus system (LVDS = Low Voltage Differential Signaling), an MSC bus system (MSC = Micro Second Channel), and a 10BASE-T1S Ethernet are known.

In a CAN bus system, messages are transmitted using the CAN and/or CAN FD protocol, as described in the ISO-11898-1:2015 standard as the CAN protocol specification with CAN FD. With CAN FD, transmission on the bus switches back and forth between a slow operating mode in a first communication phase (arbitration phase) and a fast operating mode in a second communication phase (data phase). With a CAN FD bus system, a data transfer rate of more than 1 Mbit per second (1Mbps) is possible in the second communication phase. For example, CAN FD is used by most manufacturers with a 500kbit/s arbitration bit rate and 2 Mbit/s data bit rate in the vehicle.

In order to enable even higher data rates in the second communication phase, there are successor bus systems for CAN FD, such as CAN-SIC and CAN XL. With CAN-SIC according to the CiA601-4 standard, a data rate of around 5 to 8 Mbit/s can be achieved in the second communication phase. With CAN XL, a data rate of > 10 Mbit/s is required in the second communication phase. The standard (CiA610-3) for this is set by the CAN in Automation (CiA) organization. This standard is currently being incorporated into ISO11898-2. In addition to pure data transport via the CAN bus, CAN XL is also intended to support other functions such as functional safety, data security and quality of service (QoS). These are elementary properties that are needed in an autonomous vehicle.

In all of the CAN-based bus systems mentioned above, a CAN_H bus signal and, ideally, a CAN_L bus signal are driven separately onto a bus for a transmission signal TxD. Here, at least in the first communication phase, a bus state is actively driven in the bus signals CAN_H, CAN_L. The other bus state is not driven and occurs due to a terminating resistor for bus lines or bus wires of the bus. With CAN XL, CAN FD and CAN SIC, the data in the second communication phase is sent to the bus at a higher data rate than in the first communication phase.

To send and receive the bus signals, transmitter/receiver devices are usually used for the individual communication participants in a CAN bus system, which are also referred to as CAN transceivers or CAN FD transceivers, etc. With CAN XL, the transmitting/receiving devices must be able to send the bus signals CAN_H, CAN_L to the bus in the second communication phase with a different physical layer and to receive them with a different reception threshold than in the first communication phase. The type of communication in the second communication phase is called FAST MODE. The physical layer corresponds to the physical layer or layer 1 of the well-known OSI model (Open Systems Interconnection Model).

With CAN XL, the data in the second communication phase can be sent to the bus at a significantly higher data rate (FAST MODE) than with CAN FD or CAN SIC. In addition, the bus levels of the bus signals CAN_H, CAN_L for the first communication phase can differ from the bus levels of the second communication phase. To ensure a low error rate, it is important that a subscriber station that is newly connected to communication on the bus recognizes in which communication phase communication is currently taking place on the bus.

If a bus system uses both transmitting/receiving devices (transceivers) that are designed for CAN XL and transmitting/receiving devices (transceivers) that are designed for CAN FD or CAN SIC, this applies to all operating phases of communication on the bus to ensure that a receiving subscriber station of the bus system can correctly recognize and evaluate the levels of the bus signals CAN_H, CAN_L. This is the only way to prevent communication disruptions on the bus, which could otherwise occur due to the different communication standards.

Disclosure of the invention

It is therefore the object of the present invention to provide a transmitter/receiver device and a method for receiving differential signals in a serial bus system, which solve the aforementioned problems. In particular, the transmitting/receiving device and the method for receiving differential signals in a serial bus system should enable reliable and inexpensive detection and treatment of bus signals, even if the physical layer is switched between two communication phases during communication on the bus.

The object is achieved by a transmitting/receiving device for transmitting and/or receiving differential signals in a serial bus system with the features of claim 1. The transmitting/receiving device has a transmitting module for transmitting a digital transmission signal from a communication control device as an analog differential signal according to a first operating mode onto a bus of the bus system in order to send a message to at least one other subscriber station of the bus system, a receiving module for receiving signals from the Bus and for generating a digital reception signal from the analog differential signal according to the first operating mode using a predetermined first reception threshold, and a reception mode setting module for setting the operating mode of the reception module, so that the reception module produces a digital reception signal from the analog differential signal according to the first Operating mode and / or an analog differential signal that was generated according to a second operating mode, with which at least one other subscriber station of the bus system sends signals to the bus, the reception mode setting module being connected between the reception module and a connection for outputting the digital reception signal the communication control device is switched.

The transmitter/receiver device described is designed in such a way that reliable and inexpensive detection of bus signals occurs during operation of the bus system. This applies in particular to such communication in which the physical layer is switched between two communication phases for communication on the bus, although a transmitter module of the subscriber station is not designed to generate such bus signals. The receiving module of the subscriber station can still reliably distinguish the respective bus states of the individual communication phases and thus the individual communication phases during communication on the bus.

The described transmitting/receiving device enables communication in accordance with the CAN XL standard CiA610-3 in particular between other subscriber stations of the bus system, even if the transmitting/receiving device is not designed to send CAN XL messages.

The transmitter/receiver device described is designed in such a way that signal levels of bus signals can be converted into a digital received signal, even if the transmitter module itself is not designed to send such signal levels to the bus. In the receiving module, the two reception thresholds that are used in the individual communication phases (arbitration phase, data phase) of a message exchanged between the subscriber stations can be different depending on the communication phase.

As a result, the transmitting/receiving device can also help ensure that a subscriber station that is added and tries to integrate into the communication on the bus does not disrupt the communication on the bus. The subscriber station can use the transmitting/receiving device to reliably detect whether the bus is free of data traffic. Since the transmitting/receiving device reliably assigns the current bus states, its newly added subscriber station will only send data to the bus itself when the bus is free. This means that adding a subscriber station, which is initially started, for example, or tries to reintegrate into the communication on the bus after an error in the bus communication, does not lead to a disruption in the communication on the bus.

As a result, the transmitting/receiving device enables the functionality of using different reception thresholds for arbitration and data phase. This not only ensures communication in the bus system between other subscriber stations with higher bit rates, but also ensures that the transferable bit rate is not reduced due to errors in communication.

Advantageous further refinements of the transmitting/receiving device are described in the dependent claims.

The transmission module is preferably not designed to send a digital transmission signal to the bus in accordance with the second operating mode.

The transmission module may be designed to generate the analog differential signals according to the first operating mode for all communication phases of a message with the same physical layer, wherein the analog differential signals were generated according to the second operating mode for two communication phases of a message with different physical layers.

According to a special embodiment, the reception module has a receiver for evaluating the differential signals received from the bus with a first reception threshold or with a second reception threshold that differs from the first reception threshold, the reception mode setting module being designed to include the receiver for evaluation to set the first reception threshold when the differential signals received from the bus were generated according to the first operating mode, and wherein the reception mode setting module is designed to set the receiver for evaluation with the second reception threshold when the differential signals received from the bus according to the second operating mode were created.

According to another special embodiment, the receiving module has a first receiver for generating the digital received signal by evaluating the differential signals received from the bus with a first reception threshold, and a second receiver for generating the digital received signal by evaluating the differential signals received by the bus with a second reception threshold, which differs from the first reception threshold.

According to one embodiment, the reception mode setting module is configured to activate the first receiver and deactivate the second receiver when the differential signals received from the bus were generated in accordance with the first operating mode, wherein the reception mode setting module is configured to activate the second receiver and deactivate the first receiver when the differential signals received from the bus have been generated in accordance with the second mode of operation.

According to another exemplary embodiment, the first receiver and the second receiver are designed and/or arranged to simultaneously evaluate the differential signals received from the bus. Here, the reception mode setting module can have at least one module for the logical AND operation of the signal output from the first receiver and the signal output from the second receiver, the output of the at least one module being connected to the connection for outputting the digital reception signal to the communication control device is.

According to yet another embodiment, the reception mode setting module has a protocol controller configured to evaluate the digital reception signal, whether or not the differential signal received from the bus was generated according to the second operating mode, and a state machine for evaluating whether the reception module for evaluating the differential signals received from the bus is set according to the evaluation result of the protocol controller, wherein the reception mode setting module is designed to set the receiving module for evaluating the differential signals received from the bus according to the evaluation result of the protocol controller when the receiving module is not set to evaluate the differential signals received from the bus according to the evaluation result of the protocol controller.

According to yet another exemplary embodiment, the reception mode setting module also has an interface module which is connected between the transmission module and a connection for outputting the digital transmission signal of the communication control device to the transmission module, and wherein the interface module is designed to evaluate whether the differential received from the bus Signals were generated according to the second operating mode or not, and for switching the transmitter module in such a way that the transmitter module cannot transmit on the bus if the evaluation shows that the received from the bus A differential signal was generated according to the second operating mode. Here, the interface module can be designed to generate a digital received signal from the differential signals received from the bus, which were generated according to the second operating mode.

The transmitter/receiver device described above can be part of a subscriber station for a serial bus system. The subscriber station can also have a communication control device for controlling communication in the bus system and for generating a digital transmission signal for the transmission module.

Optionally, the subscriber station is designed for communication in a bus system in which exclusive, collision-free access of a subscriber station to the bus of the bus system is guaranteed at least temporarily.

The aforementioned object is also achieved by a method for receiving differential signals in a serial bus system with the features of claim 14. The method is carried out with a transmitting/receiving device which has a transmitting module, a receiving module and a receiving mode setting module for sending and/or receiving signals in a serial bus system, the transmitting module being used to send a digital transmission signal from a communication control device as an analog differential signal is designed according to a first operating mode on a bus of the bus system in order to send a message to at least one other subscriber station of the bus system, and wherein the method has the steps of receiving, with the reception module, signals from the bus, generating, with the reception module, a digital reception signal from the analog differential signal according to the first operating mode using a predetermined first reception threshold, setting, with the reception mode setting module, the operating mode of the reception module, so that the reception module produces a digital reception signal from the analog differential signal according to the first operating mode and / or an analog differential signal that was generated according to a second operating mode, with which at least one other subscriber station of the bus system sends signals onto the bus, and forwarding, with the reception mode setting module, which is between the reception module and a connection for outputting the digital Reception signal is connected to the communication control device, of the digital reception signal to the communication control device.

The method offers the same advantages as previously mentioned with regard to the receiving module.

Further possible implementations of the invention also include combinations of features or embodiments described above or below with regard to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

drawings

• 1 ein vereinfachtes Blockschaltbild eines Bussystems gemäß einem ersten Ausführungsbeispiel;
• 2 ein Schaubild zur Veranschaulichung des Aufbaus einer Nachricht, die von Teilnehmerstationen des Bussystems gemäß dem ersten Ausführungsbeispiel gesendet werden kann;
• 3 ein Beispiel für den zeitlichen Verlauf von Sendesignalen TxD einer ersten Teilnehmerstation beim Umschalten der Betriebsarten bzw. Betriebszustände der Sende-/Empfangseinrichtung der ersten Teilnehmerstation zwischen den verschiedenen Kommunikationsphasen einer Nachricht;
• 4 ein Beispiel für den idealen zeitlichen Verlauf von Bussignalen CAN_H, CAN_L, die von der ersten Teilnehmerstation des Bussystems für die Nachricht von 2 auf einen Bus des Bussystems gesendet werden;
• 5 den zeitlichen Verlauf einer Differenzspannung VDIFF, die sich auf dem Bus des Bussystems infolge der Bussignale von 4 ausbildet;
• 6 ein Blockschaltbild einer Sende-/Empfangseinrichtung mit einem Empfangsmodul für eine zweite Teilnehmerstation des Bussystems gemäß dem ersten Ausführungsbeispiel;
• 7 ein Beispiel für einen zeitlichen Verlauf eines digitalen Sendesignals, welches von der zweiten Teilnehmerstation in einer Arbitrationsphase (SIC-Betriebsart) der Nachricht von 2 in Bussignale CAN_H, CAN_L für den Bus des Bussystems von 1 umgesetzt werden soll;
• 8 den zeitlichen Verlauf der Bussignale CAN_H, CAN_L beim Wechsel zwischen einem rezessiven Buszustand zu einem dominanten Buszustand und zurück zu dem rezessiven Buszustand, die von der zweiten Teilnehmerstation in der Arbitrationsphase (SIC-Betriebsart) aufgrund des Sendesignals von 7 auf den Bus gesendet werden;
• 9 ein Beispiel für einen zeitlichen Verlauf eines digitalen Sendesignals, welches von der zweiten Teilnehmerstation in einer Datenphase der Nachricht von 2 in Bussignale CAN_H, CAN_L für den Bus des Bussystems von 1 umgesetzt werden soll;
• 10 den zeitlichen Verlauf der Bussignale CAN_H, CAN_L, die von der zweiten Teilnehmerstation in der Datenphase aufgrund des Sendesignals von 9 auf den Bus gesendet werden;
• 11 ein Blockschaltbild einer Sende-/Empfangseinrichtung mit einem Empfangsmodul für eine zweite Teilnehmerstation des Bussystems gemäß einem zweiten Ausführungsbeispiel; und
• 12 ein Blockschaltbild einer Sende-/Empfangseinrichtung mit einem Empfangsmodul für eine zweite Teilnehmerstation des Bussystems gemäß einem dritten Ausführungsbeispiel.

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

• 1 a simplified block diagram of a bus system according to a first exemplary embodiment;
• 2 a diagram illustrating the structure of a message that can be sent by subscriber stations of the bus system according to the first exemplary embodiment;
• 3 an example of the time course of transmission signals TxD of a first subscriber station when switching the operating modes or operating states of the transmitting/receiving device of the first subscriber station between the different communication phases of a message;
• 4 an example of the ideal timing of bus signals CAN_H, CAN_L, which are sent by the first subscriber station of the bus system for the message from 2 be sent to a bus of the bus system;
• 5 the time course of a differential voltage VDIFF, which is on the bus of the bus system as a result of the bus signals from 4 trains;
• 6 a block diagram of a transmitting/receiving device with a receiving module for a second subscriber station of the bus system according to the first exemplary embodiment;
• 7 an example of a time course of a digital transmission signal which is sent by the second subscriber station in an arbitration phase (SIC operating mode) of the message from 2 in bus signals CAN_H, CAN_L for the bus of the bus system 1 should be implemented;
• 8th the time course of the bus signals CAN_H, CAN_L when changing between a recessive bus state to a dominant bus state and back to the recessive bus state, which is sent by the second subscriber station in the arbitration phase (SIC operating mode) due to the transmission signal from 7 be sent to the bus;
• 9 an example of a time course of a digital transmission signal which comes from the second subscriber station in a data phase of the message from 2 in bus signals CAN_H, CAN_L for the bus of the bus system 1 should be implemented;
• 10 the time course of the bus signals CAN_H, CAN_L, which are sent by the second subscriber station in the data phase due to the transmission signal from 9 be sent to the bus;
• 11 a block diagram of a transmitting/receiving device with a receiving module for a second subscriber station of the bus system according to a second exemplary embodiment; and
• 12 a block diagram of a transmitting/receiving device with a receiving module for a second subscriber station of the bus system according to a third exemplary embodiment.

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

Description of the exemplary embodiments

1 shows a bus system 1, which can be, for example, at least in sections a CAN bus system, a CAN FD bus system, etc. The bus system 1 can be used in a vehicle, in particular a motor vehicle, an airplane, etc., or in a hospital, etc.

In 1 the bus system 1 has a plurality of subscriber stations 10, 20, 30, each of which is connected to a bus 40 or bus line with a first bus wire 41 and a second bus wire 42. The bus wires 41, 42 can also be called CAN_H and CAN_L for the signals on the bus 40. Messages 45, 46, 47 can be transmitted in the form of signals between the individual subscriber stations 10, 20, 30 via the bus 40. The subscriber stations 10, 20, 30 can be, for example, control devices or display devices of a motor vehicle.

As in 1 shown, the subscriber stations 10, 30 each have a communication control device 11 and a transmitting/receiving device 12. The transmitting/receiving device 12 has a transmitting module 121 and a receiving module 122.

The subscriber station 20 has a communication control device 21 and a transmitting/receiving device 22. The transmitting/receiving device 22 has a transmitting module 221, a reception mode setting module 25 and a receiving module 222.

The transmitting/receiving devices 12 of the subscriber stations 10, 30 and the transmitting/receiving device 22 of the subscriber station 20 are each connected directly to the bus 40, even if this is the case 1 is not shown.

The communication control devices 11, 21 each serve to control communication between the respective subscriber station 10, 20, 30 via the bus 40 with at least one other subscriber station of the subscriber stations 10, 20, 30 that are connected to the bus 40.

The communication control devices 11 create and read first messages 45, 47, which are, for example, modified CAN messages 45, 47. The modified CAN messages 45, 47 are, for example, based on the CAN XL format. The transmitting/receiving device 12 is used to send and receive the messages 45, 47 from the bus 40. The transmitting module 121 receives a digital transmission signal TxD created by the communication control device 11 for one of the messages 45, 47 and sets this into signals on the bus 40 around. The digital transmission signal TxD can be a pulse-width modulated signal. The reception module 122 receives signals sent on the bus 40 corresponding to the messages 45 to 47 and uses them to generate a digital reception signal RxD. The reception module 122 sends the reception signal RxD to the communication control device 11. The reception module 122, the digital received signal RxD. Additionally, the communication control devices 11 can be designed to create and read second messages 46, which are CAN SIC messages 46, for example. The transmitting/receiving devices 12 can be designed accordingly.

The communication control device 21 can be designed like a conventional CAN controller according to ISO 11898-1:2015, i.e. like a CAN FD tolerant Classical CAN controller or a CAN FD controller or a CAN SIC controller. The communication control device 21 creates and reads second messages 46, for example CAN SIC messages. The transmitting/receiving device 22 is used to send and receive the messages 46 from the bus 40. The transmitting module 221 receives a digital transmission signal TxD created by the communication control device 21 and converts this into signals for a message 46 on the bus 40. The reception module 222 receives signals sent on the bus 40 corresponding to the messages 45 to 47 and uses them to generate a digital reception signal RxD. The reception mode setting module 25 is described in more detail below. Otherwise, the transmitting/receiving device 22 can be designed like a conventional CAN-SIC transceiver.

To send messages 45, 46, 47 with CAN SIC or CAN XL, proven properties are adopted that are responsible for the robustness and user-friendliness of CAN and CAN FD, in particular the frame structure with identifier and arbitration according to the well-known CSMA/CR method. The CSMA/CR method means that there must be so-called recessive states on the bus 40, which can be overwritten by other subscriber stations 10, 20, 30 with dominant levels or dominant states on the bus 40.

With the two subscriber stations 10, 30, it is possible to form and then transmit messages 45, 47 with different CAN formats, in particular the CAN FD format or the CAN SIC format or the CAN XL format, as well as the reception of such messages 45, 47. This is described in more detail below for a message 45.

2 shows a frame 450 for the message 45, which is in particular a CAN XL frame, as provided by the communication control device 11 for the transmitting/receiving device 12 for sending to the bus 40. Here, the communication control device 11 creates the frame 450 in the present exemplary embodiment as compatible with CAN FD. Alternatively, the 450 frame is compatible with CAN XL.

According to 2 the frame 450 for CAN communication on the bus 40 is divided into different communication phases 451, 452, namely an arbitration phase 451 (first communication phase) and a data phase 452 (second communication phase). The frame 450 has, after a start bit SOF, an arbitration field 453, a control field 454, a data field 455, a checksum field 456 and a frame termination field 457. The checksum field 456 and the frame termination field 457 form a frame end phase 456, 457 of the frame 450.

In the arbitration phase 451, with the aid of an identifier (ID) with, for example, bits ID28 to ID18 in the arbitration field 453, a bit-by-bit negotiation is made between the subscriber stations 10, 20, 30 as to which subscriber station 10, 20, 30 will send the message 45, 46 with the highest priority would like to and therefore gets exclusive access to the bus 40 of the bus system 1 for the next time for sending in the subsequent data phase 452. In the arbitration phase 451, a physical layer like CAN and CAN-FD is used. The physical layer corresponds to the physical layer or layer 1 of the well-known OSI model (Open Systems Interconnection Model).

An important point during phase 451 is that the known CSMA/CR method is used, which allows simultaneous access of the subscriber stations 10, 20, 30 to the bus 40 without the higher priority message 45, 46 being destroyed. This makes it relatively easy to add additional bus subscriber stations 10, 20, 30 to the bus system 1, which is very advantageous.

The CSMA/CR method means that there must be so-called recessive states on the bus 40, which can be overwritten by other subscriber stations 10, 20, 30 with dominant levels or dominant states on the bus 40. In the recessive state, there are 10, 20, 30 high-resistance conditions at the individual subscriber station, which, in combination with the parasites in the bus circuitry, results in longer time constants. This leads to a limitation of the maximum bit rate of today's CAN FD physical layer to currently around 2 megabits per second in real vehicle use.

In the data phase 452, in addition to a part of the control field 454, the user data of the CAN-XL frame 450 or the message 45 from the data field 455 and the checksum field 456 are sent. The checksum field 456 can contain a checksum for the data of the data phase 452 including the stuff bits, which are inserted as an inverse bit by the sender of the message 45 after a predetermined number of identical bits, in particular 10 identical bits. At the end of the data phase 452, the arbitration phase 451 is switched back to.

At least one acknowledge bit may be contained in an end field in the frame termination field 457. There may also be a sequence of 11 identical bits indicating the end of the CAN XL frame 450. The at least one acknowledge bit can be used to indicate whether or not a receiver has discovered an error in the received CAN XL frame 450 or the message 45.

A sender of the message 45 only begins sending bits of the data phase 452 to the bus 40 when the subscriber station 10 as the sender has won the arbitration and the subscriber station 10 as the sender therefore has exclusive access to the bus 40 of the bus system 1 for sending .

Thus, in the arbitration phase 451, the subscriber stations 10, 30 partially use, in particular up to the FDF bit (inclusive), a format known from CAN/CAN-FD in accordance with ISO11898-1:2015 as the first communication phase. However, in comparison to CAN or CAN FD, an increase in the net data transfer rate, in particular to over 10 megabits per second, is possible in the data phase 452 as the second communication phase. It is also possible to increase the size of the user data per frame, in particular to approximately 2kbytes or any other value.

As in 3 shown, the transmitting/receiving devices 12 use a physical layer 451_P both in the arbitration phase 451 and in the frame end phase 456, 457. The same applies to the transmitting/receiving device 22. In contrast to this, the transmitting/receiving device 12 can use a physical layer 452_P in the data phase 452, which differs from the physical layer 451_P, as already described previously.

In the transmission signal TxD from 3 The levels or values HI (High = High) or 1 of the FDF bit and the XLF bit signal that a switch is to be made to the data phase 452 of a frame 450. The resXL bit is always sent in frame 450 with a level or value LW (Low) or 0. The resXL bit may be used differently in subsequent formats to frame 450. The digital transmission signal TxD can be a pulse-width modulated signal or can subsequently be pulse-width modulated. Starting with the ADH bit at the end of the arbitration phase 451, a sequence ADS will be sent, which also includes bits DH1, DH2 and DL1. The sequence ADS indicates that the transmitting/receiving device 22 has to switch into an operating mode of the data phase 452. After the FCP field with bits FCP3 to FCP0, starting with the DAH bit at the end of the data phase 452, a DAS sequence is sent, which also includes a bit AH1 and additional bits not shown. The sequence DAS indicates that the transceiver 22 is to be switched from the operating mode of the data phase 452 to the operating mode of the arbitration phase 451.

After receiving the appropriate signals according to 4 and 5 from the transmission signal TxD from 3 are formed and sent to the bus 40, each transmitting/receiving device 12 generates the associated received signal RxD from 3 . The received signal RxD from 3 ideally has no time offset from the transmission signal TxD, as in 3 shown.

The transmitting/receiving device 12 recognizes the received signal RxD from based on the HI levels of the FDF bit and the XLF bit in the example 3 that a switchover to data phase 452 must be made. In particular, the bit duration t_bt2 of the bits of the transmission signal TxD in the data phase 452 is less than the bit duration t_bt1 of the bits of the transmission signal TxD in the arbitration phase 451. As a result, the bit rate of the signals on the bus 40 in the data rate 452 is higher than in the arbitration phase 451. For this purpose, the operating mode of the transmitting/receiving device 12 can be switched, in particular by switching the transmitting/receiving device 12 from sending and/or receiving signals with the physical layer 451_P to the physical layer 452_P. There are two operating modes for the physical layer 452_P, as per 4 and 5 described in more detail.

After receiving the bits DH2, DL2, AH of the received signal RxD from 3 the transmitting/receiving device 12 recognizes that a switchover from the data phase 452 back to the arbitration phase 451 is to be undertaken. Accordingly, the transmitting/receiving device 12 is switched from sending and/or receiving signals with the physical layer 452_P to the physical layer 451_P.

4 shows on the left that the subscriber stations 10, 20, 30 in the arbitration phase 451 send signals CAN_H, CAN_L to the bus 40, which alternately have at least one dominant state 401 or at least one recessive state 402. After the arbitration in the arbitration phase 451, one of the participant stations 10, 20, 30 is determined as the winner.

Assume that the first subscriber station 10 has won the arbitration. Then the transmitting/receiving device 12 of the subscriber station 10 switches its physical layer 451_P at the end of the arbitration phase 451 from a first operating mode (SLOW), which can also be designed as a SIC operating mode, to a second operating mode (FAST_TX), since the subscriber station 10 in data phase 452 is the sender of message 45. As in 4 shown, the transmission module 121 then generates in the data phase 452 or in the second operating mode (FAST_TX) depending on a transmission signal TxD one after the other and thus serially the states L0 or L1 with the physical layer 452_P for the signals CAN_H, CAN_L on the bus 40. The frequency of the signals CAN_H, CAN_L can be increased in the data phase 452, as on the right in 4 shown. Thus, the net data transfer rate in the data phase 452 is increased compared to the arbitration phase 451. In contrast, the transmitting/receiving device 12 of the subscriber station 30 switches its physical layer 451_P at the end of the arbitration phase 451 from the first operating mode (SLOW or SIC) to a third operating mode (FAST_RX), since the subscriber station 30 is only a receiver in the data phase 452, i.e no transmitter, the frame is 450. After the end of the arbitration phase 451, all transmitting/receiving devices 12 of the subscriber stations 10, 30 switch their operating mode to the first operating mode (SLOW or SIC). Thus, all transmitting/receiving devices 12 also switch their physical layer, as described above.

According to 5 Ideally, in the arbitration phase 451, a difference signal VDIFF = CAN_H - CAN_L with values of VDIFF = 2V for dominant states 401 and VDIFF = 0V for recessive states 402 is formed on the bus 40. This is on the left in 5 shown. In contrast, in the data phase 452 on the bus 40, a difference signal VDIFF = CAN_H - CAN_L is formed corresponding to the states L0, L1 of 4 like on the right in 5 shown. The state L0 has a value VDIFF = 1V. The state L1 has a value VDIFF = -1V.

The reception module 122 can distinguish the states 401, 402 with two of the reception thresholds T1, T2, T3, which lie in the areas TH_T1, TH_T2, TH_T3. For this purpose, the receiving module 122 samples the signals from 4 or 5 at times t_A, as in 5 shown. To evaluate the scanning result, the reception module 122 uses the reception threshold T1 of, for example, 0.7 V and the reception threshold T2 of, for example, -0.35 V in the arbitration phase 451. In contrast, the reception module 122 in the data phase 452 only uses signals that have the reception threshold T3 were evaluated. When switching between the first to third operating modes (SLOW or SIC, FAST_TX, FAST_RX), previously referred to 4 are described, the reception module 122 switches the reception thresholds T2, T3. This is described in more detail below.

The reception threshold T2 is used to detect whether the bus 40 is free when the subscriber station 12 is newly switched into the communication on the bus 40 and tries to integrate into the communication on the bus 40. The reception threshold T2 is called OOB (= Out-of-Boundary = outside the limit value) in the standard for CAN. The conditions for a traffic-free bus to be able to communicate according to the CAN-XL standard are that no dominant state 401 occurs, which typically has the differential voltage VDIFF = 2V. This means that the reception threshold T1 of, for example, 0.7 V must not be exceeded. In addition, no levels may occur according to state L1, which typically has the differential voltage VDIFF = 2V -1V. This means that the reception threshold T2 must not fall below -0.35 V, for example.

Each subscriber station 10, 30 switches the operating mode of the transceiver 12 to the operating mode of the arbitration phase 451 when the subscriber station 12 is newly switched into communication on the bus 40.

The connection of the subscriber station 10 may be necessary if the subscriber station 10 is initially started and is to be integrated into the communication on the bus 40. On the other hand, it may be necessary to connect the subscriber station 10 if the subscriber station 10 tries to reintegrate itself into the communication on the bus 40 after an error in the bus communication Only when it is recognized that the bus is free can the subscriber station 10 itself send data, in particular messages 45, 47, to the bus 40 in the cases mentioned.

Table 1 below shows the values that can be set for the individual reception thresholds on bus 40. VDIFF_min indicates the lower limit for the individual areas TH_T1, TH_T2, TH_T3, which may be set minimally for the corresponding reception threshold T1, T2, T3 in V. VDIFF_typ indicates the value that is typically or usually set for the corresponding reception thresholds T1, T2, T3 in V. VDIFF_max specifies the upper limit for the individual areas TH_T1, TH_T2, TH_T3, which may be set in V for the corresponding reception threshold T1, T2, T3. Table 1: Tolerance ranges of the reception thresholds T1, T2, T3 Reception threshold VDIFF_min in V VDIFF_type in V VDIFF_max in V Tolerance in V T1 0.5 0.7 0.9 +/- 0.2 T2 -0.45 -0.35 -0.25 +/- 0.1 T3 -0.1 0.0 +0.1 +/- 0.1

6 shows the basic structure of the transmitting/receiving device 22 of the second subscriber station 20. In contrast to the subscriber stations 10, 30, the subscriber station is designed for sending CAN FD or CAN SIC messages 46, but not for sending CAN XL messages 45 , 47 designed. However, the transmitting/receiving device 22 of the second subscriber station 20 is also designed to receive CAN XL messages 45, 47.

In 6 the transmission module 221 is only shown in simplified form. The transmission module 221 is connected directly to the bus 40 via connections CANH, CANL in order to be able to send a transmission signal TxD from the communication control device 21 to the bus 40. The communication control device 21 sends the transmission signal TxD to the transmission module 221 via a connection TXD.

According to 6 The receiving module 222 is also connected directly to the bus 40 via the CANH, CANL connections. The reception module 222 has a first receiver 2221, which is designed only for receiving and evaluating CAN SIC messages 46 in order to generate the digital reception signal RxD. In addition, the reception module 222 has a second receiver 2222. The second receiver 2222 can be designed as a comparator, in particular a low-voltage comparator. The reception module 222 sends or outputs the reception signal RxD to the communication control device 21 via a connection RXD.

The first receiver 2221 and the second receiver 2222 are designed and/or arranged to simultaneously evaluate the differential signals CAN_H, CAN_L received from the bus 40.

The reception mode setting module 25 has a protocol controller 251 and a state machine 252. The reception mode setting module 25 is designed to activate or deactivate the receiver 2221 with a switching signal S_1 or the reception comparator 2222 with a switching signal S_2. This will be described in more detail later.

7 shows an example of a transmission signal TxD, which the transmission module 221 receives from the device 21 in the arbitration phase 451. An example of the transmission signal TxD, which the transmission module 221 receives from the device 21 in the data phase 452, is shown in 9 shown. As a result of the signals from 7 or. 9 the transmitter module generates 221 signals according to 8th or. 10 on the bus 40. The subscriber stations 10, 30 are also designed to send and/or receive CAN SIC messages 46 in particular, as described above. Therefore, the description of the signals from applies 7 until 10 also for subscriber stations 10, 30.

7 shows an example of a part of the digital transmission signal TxD, which the transmission module 221 receives from the communication control device 21 in the arbitration phase 451, and from which the signals CAN_H, CAN_L for the bus 40 are generated. In 9 the transmission signal TxD changes from a state LW (Low = Low) to a level or value HI (High = High) and back again to the level or value LW (Low = Low).

The received signal RxD is ideally identical to the transmitted signal TxD. In such an ideal case, there is no transmission delay/runtime, particularly over bus 40, and no possible reception errors.

As in 8th shown in more detail, the transmission module 221 can be used for the transmission signal TxD 7 In the CAN SIC or CAN XL operating mode, the signals CAN_H, CAN_L from 8th for the bus wires 41, 42. In contrast to 4 , is at the signals from 8th There is also a status 403 (sic). State 403 (sic) can be of different lengths, as shown with state 403_0 (sic) when transitioning from state 402 (rec) to state 401 (dom) and state 403_1 (sic) when transitioning from state 401 ( dom) to state 402 (rec). The state 403_0 (sic) is shorter in time than the state 403_1 (sic). To get signals according to 8th To generate, the transmitter module 221 is switched to a SIC operating mode (SIC mode).

For the subscriber stations 10, 30, passing through the short sic state 403_0 according to the CiA610-3 standard for CAN XL is not required and the state depends on the type of implementation. The time duration of the “long” state 403_1 (sic) is specified for CAN-SIC as well as for the SIC operating mode for CAN-XL as t_sic < 530ns, starting with the rising edge on the transmit signal TxD from 7 .

In the “long” state 403_1 (sic), the transmitter module 221 or the transmitter module 121 should adapt the impedance between the bus wires 41 (CANH) and 42 (CANL) as well as possible to the characteristic characteristic impedance Zw of the bus line used. Here Zw=100Ohm or 120Ohm. This adjustment prevents reflections and thus allows operation at higher bit rates. For the sake of simplicity, we will always refer to state 403 (sic) or sic state 403 below.

9 shows an example of another part of the digital transmission signal TxD, which the transmission module 221 receives from the communication control device 21 in the data phase 452, and from which the signals CAN_H, CAN_L for the bus 40 are generated. In 9 the transmission signal TxD changes several times from the level or value HI (High = High) to a level or value LW (Low = Low) and again to a level or value HI (High = High) and so on.

As in 10 shown in more detail, the transmission module 221 generates the transmission signal TxD from 9 the signals CAN_H, CAN_L for the bus wires 41, 42 such that the state L0 ( 10 ) for a state LW (Low = Low) of the transmission signal TxD from 9 trains. In addition, the state L1 ( 10 ) for a level or value HI (High = High) of the transmission signal TxD from 9 out of.

For the two bus states 401, 402 according to 8th The transmitter module 221 uses a dominant bus state and a recessive bus state, as described above. In addition, the transmit module 221 generates the bus state 403 (sic), as described above. In contrast, the bus states are L0, L1 10 a first bus state L0 and a second bus state L1, both driven as specified for CAN XL.

The receiving module 222 can receive both the signals 4 or. 5 as well as the signals according to 8th and 10 received in the two different communication phases, namely the SIC mode or arbitration phase 451 and the data phase 452. For this purpose, the reception module 122 switches the reception thresholds T2, T3 for the respective operating modes, as previously referred to 4 and 5 described.

During operation of the bus system 1, the reception mode setting module 25 checks in the RxD signal generated by the first receiver 2221 whether the resXL bit has the value H, in particular 1, or the value L, in particular 0. If the resXL bit has the value H, in particular 1, a CAN XL message 45, 47 is currently being sent via bus 40. If the resXL bit has the value L, in particular 0, a CAN XL message 46 is currently being sent via bus 40. In addition, the reception mode setting module 25, in particular its protocol controller 251, checks in the RxD signal generated by the first receiver 2221 whether the ADS sequence indicates that the CAN XL message 45, 47 is connected to the second physical layer 452_P via the Bus 40 is sent.

Recognizes the reception mode setting module 25, in particular its protocol controller 251, that a CAN XL message 45, 47 is currently being sent via the bus 40 and/or in the case of the message 45, 47 from the bus 40 the second physical layer 452_P is used, the reception mode setting module 25 deactivates the first receiver 2221 by a corresponding signal S_1. As a result, analog components that detect a differential voltage VDIFF of a minimum of +1.5 V and a maximum of +3.00 V are deactivated. In addition, the reception mode setting module 25 activates the second receiver 2222 by a corresponding signal S_2. As a result, analog components are activated that detect a differential voltage VDIFF of a minimum of -0.1 V and a maximum of +0.1 V.

The reception mode setting module 25 can send the signals S_1, S_2 one after the other. Alternatively, the reception mode setting module 25 can send the signals S_1, S_2 at least partially simultaneously.

If the second receiver 2222 is activated, the second receiver 2222 uses at least one reception threshold in the FAST_RX operating mode to detect level L1 for CAN_H with voltages V _{CAN_H1} +1.5V to +2.46V. In addition, the second receiver 2222 uses at least one reception threshold in the FAST_RX operating mode to detect level L1 for CAN_L with voltages V _{CAN_H1} +2.25V to +3.51V. In particular, the reception threshold T3 is used as the reception threshold 5 used to detect a differential voltage VDIFF of a minimum of -0.1 V and a maximum of +0.1 V. In other words, in the FAST_RX operating mode, the second receiver 2222 checks level L1 for CAN_H with voltages V _{CAN_H1} +1.5V to +2.46V and checks level L1 for CAN_L with voltages V _{CAN_H1} +2.25V to +3.51V.

The reception mode setting module 25, in particular its protocol controller 251, can also be designed to check in the RxD signal generated by the first receiver 2221 whether the DAS sequence at the end of the data phase 452 indicates that the data phase 452 of the CAN XL message 45, 47 has ended and the second physical layer 452_P is to be switched back to the first physical layer 451_P.

If the reception mode setting module 25, in particular its state machine 252, recognizes that the switch from the FAST_RX operating mode to the SIC operating mode for the arbitration phase 451 has taken place, as described above, the reception mode setting module 25 deactivates the second receiver 2222 by means of a corresponding signal S_2. If the switch from the FAST_RX operating mode to the SIC operating mode for the arbitration phase 451 has taken place, the state machine 252 no longer detects the level L1, L0 of a CN XL message 45, 47 in the data phase 452. In addition, the reception mode setting module 15 activates the first receiver 2222 by a corresponding signal S_1. As a result, analog components are activated that detect a differential voltage VDIFF of a minimum of +1.5 V and a maximum of +3.00 V. In particular, the reception threshold T1 is used as the reception threshold 5 used to detect a differential voltage VDIFF of a minimum of +0.5 V and a maximum of +0.9 V.

The reception mode setting module 25 can send the signals S_2, S_1 one after the other. Alternatively, the reception mode setting module 25 can send the signals S_2, S_1 at least partially simultaneously.

The subscriber station 20 can then again take part in the arbitration for sending the next message 45, 46, 47 via the bus 40. If the subscriber station 20 wins the arbitration this time, the subscriber station 20 can send a message 46. Otherwise, one of the subscriber stations 10, 30 sends a message 45, 46, 47 again, with the subscriber station 20 again proceeding as described above.

According to a modification of the first exemplary embodiment, only, for example, the receiver 2221 is used, the reception threshold T1 of which can be switched to the reception threshold T3, and in which the reception threshold T3 can be switched to the reception threshold T1.

According to the present exemplary embodiment and its modification, the reception mode setting module 25 thus sets the reception thresholds T1, T3 in accordance with the currently required operating mode (SIC, FAST_RX) of the transmitting/receiving device 22. Nevertheless, the transmitting/receiving device 22 is more cost-effective than a transmitting/receiving device 12, since the transmitting/receiving device 220 does not have the full functionality of a CAN-SIC XL transmitting/receiving device 12.

11 shows a transmitting/receiving device 220 according to a second exemplary embodiment. The transmitting/receiving device 220 can be used instead of a transmitting/receiving device 22 in the bus system 1 1 be used.

In contrast to the transceiver 22 of the previous exemplary embodiment, the transceiver 220 of the present exemplary embodiment has a reception module 2220 and a reception mode setting module 250. The reception mode setting module 250 has at least one Logic module 253. The at least one logic module 253 is in particular an AND logic module.

The reception module 2220 of the present exemplary embodiment has a third receiver 2223 instead of the second receiver 2222. The first receiver 2221 and the third receiver 2222 are designed and / or arranged to simultaneously evaluate the differential signals CAN_H, CAN_L received from the bus 40.

Only the differences from the previous exemplary embodiment are described below.

In contrast to the previous exemplary embodiment, the receivers 2221, 2223 are both active during operation of the transmitting/receiving device 220. As a result, the receivers 2221, 2223 are both active in the arbitration phase 451 and in the data phase 452.

The first receiver 2221 uses the reception threshold T1, as is usual for a SIC subscriber station and as described above. As a result, the first receiver 2221 outputs a value HI (high = high) in its digital reception signal for all voltage values of the differential voltage VDIFF that are below, for example, 0.7 V.

However, the third receiver 2223 is designed to use the reception threshold T2. The reception threshold T2 is used to detect whether a message 45, 47 is currently being transmitted on the bus 40. This allows the third receiver 2223 to check whether the differential voltage VDIFF has voltage values that are below -0.43 V or below -0.23 V, respectively, as described previously. The third receiver 2223 only outputs a value HI (High = High) in its digital reception signal when the difference voltage VDIFF is above the reception threshold T2. Thus, the third receiver 2223 outputs the differential voltage VDIFF for a level L1 5 the value LW (low = low) in its digital reception signal.

Due to the AND operation of the signals from the receivers 2221, 2223 by the at least one logic module 253, all bus states with level L1 of the differential voltage VDIFF of 5 hidden or displayed as the value LW (Low = Low). The reception mode setting module 250 outputs a digital reception signal RxD, which has the value HI (High = High) as long as voltage values of the differential voltage VDIFF are received, which lie between the voltage values of the reception thresholds T1, T2. For example, the received signal RxD has the value HI (High = High) as long as the voltage values of the differential voltage VDIFF on the bus 40 are between +0.7 V and -0.35 V. Otherwise, the received signal RxD has the value LW (Low = Low).

(Please check what additional information about OOB Comparator needs to be included here from page 4 and page 5 of the invention disclosure, especially for the SIC operating mode)

In this way, the receiving module 2220 with the third receiver 2223 can prevent the transceiver 220 from disrupting the communication on the bus 40 with an error message or going into the protocol exception state.

The reception module 2220 is thus designed to use the reception thresholds T1, T2 to determine the operating mode (SIC) or the corresponding signals 4 and 5 on the bus 40 and to tolerate the operating mode (FAST_RX) on the bus 40. Nevertheless, the transmitting/receiving device 2220 is more cost-effective than a transmitting/receiving device 12, since the transmitting/receiving device 220 does not have the full functionality of a CAN-XL transmitting/receiving device 12.

12 shows a transmitting/receiving device 2200 according to a third exemplary embodiment. The transmitting/receiving device 2200 can be used instead of a transmitting/receiving device 22 or a transmitting/receiving device 220 in the bus system 1 1 be used.

In contrast to the transmitting/receiving device 220 of the previous exemplary embodiment, the transmitting/receiving device 2200 has a reception mode setting module 2500, which has an interface module 254 in addition to the logic module 253 of the previous exemplary embodiment. The interface module 254 enables the transceiver 2200 of the present exemplary embodiment to not only receive messages 46, but also to correctly receive messages 45, 47.

The interface module 253 is designed to receive a message 45, 47 from the bus 40, to prepare it appropriately for the communication control device 21 and to forward the message 45, 47 to the communication control device 21 as an RxD signal. The interface module 254 therefore has the functionality of a reception module 122 of a transmitting/receiving device 12. However, the interface module 254 does not have the functionality of a transmitting module 121 of a transmitting/receiving device 12.

During operation of the transmitting/receiving device 2200, the interface module 254 checks whether a message 45, 47 is received. If this is the case, the interface module 254 outputs a signal S_3 to the transmission module 221 in order to deactivate the transmission module 221. As a result, the transmission module 221 cannot send on the bus 40. More specifically, this means that the transmission module 221 cannot send the transmission signal TxD onto the bus 40. (- After the end of the message 45, 47, the interface module 254 outputs a signal S_3 to the transmission module 221 in order to set the transmission module 221 back to the normal state. This allows the transmission module 221 to transmit on the bus 40.

The setting, in particular switching, of the operating modes of the transmitting/receiving device 2200 is therefore carried out by the receiving mode setting module 2500, so that no FAST_TX operating mode is possible, but only the FAST_RX operating mode. If the switchover to the FAST_TX operating mode occurs, the reception mode setting module 2500, more precisely its interface module 254, sets the transmission module 221, as previously described.

The design of the transmitting/receiving device 2200 of the present exemplary embodiment is particularly advantageous if a firmware update is to be carried out. The data for the firmware update (firmware update) can therefore be received at up to, for example, 20 Mbit/sec. This allows the firmware update (firmware update) to take place significantly faster than in the case where only messages 46 can be received.

The reception mode setting module 2500 is thus designed to set the reception thresholds T1, T2 in order to set the operating modes (SIC, FAST_RX) or the corresponding signals of 4 and 5 can be seen on bus 40. The reception mode setting module 2500, more precisely its interface module 254, also enables the transmitting/receiving device 2200 to receive not only CAN SIC messages 46, but also messages 45, 47 in the FAST_RX operating mode.

Nevertheless, the transmitting/receiving device 2200 is more cost-effective than a transmitting/receiving device 12, since the transmitting/receiving device 2200 does not have the full functionality of a CAN-XL transmitting/receiving device 12.

All previously described configurations of the reception module 222, 2220, the transmitting/receiving devices 22, 220, 2200, the subscriber stations 10, 20, 30, the bus system 1 and the method carried out therein according to the first and second exemplary embodiments and their modifications can be implemented individually or in can be used in all possible combinations. In addition, the following modifications in particular are conceivable.

The previously described bus system 1 according to the first and second exemplary embodiments is described using a bus system based on the CAN protocol. However, the bus system 1 according to the first and/or second exemplary embodiment may alternatively be another type of communication network in which the signals are transmitted as differential signals. It is advantageous, but not an essential requirement, that in the bus system 1 exclusive, collision-free access of a subscriber station 10, 20, 30 to the bus 40 is guaranteed at least for certain periods of time.

The bus system 1 according to the first and/or second exemplary embodiments and their modifications is in particular a bus system in which communication can be carried out between at least two of the subscriber stations 10, 20, 30 according to two different CAN standards, such as CAN-HS or CAN FD or CAN SIC or CAN XL. However, the bus system 1 may be another communication network in which the signals are transmitted as differential signals and serially over the bus 40. The functionality of the exemplary embodiments described above can therefore be used, for example, in transmitting/receiving devices 12, 22 that are to be operated in such a bus system.

The number and arrangement of the subscriber stations 10, 20, 30 in the bus system 1 according to the first and second exemplary embodiments and their modifications can be selected as desired.

Claims (14)

Transmitting/receiving device (22; 220; 2200) for sending and/or receiving signals in a serial bus system (1), with a transmission module (221) for sending a digital transmission signal (TxD) of a communication control device (22) as an analog differential signal (CAN_H, CAN_L) according to a first operating mode (SIC) to a bus (40) of the bus system (1) in order to at least one to send a message (46) to another subscriber station (10; 20; 30) of the bus system (1), a reception module (222; 2220) for receiving signals (CAN_H, CAN_L) from the bus (40) and for generating a digital reception signal (RxD) from the analog differential signal (CAN_H, CAN_L) according to the first operating mode (SIC). a predetermined first reception threshold (T1), and a reception mode setting module (25; 250; 2500) for setting the operating mode (SIC; FAST_RX) of the reception module (222; 2220), so that the reception module (222; 2220) receives a digital reception signal (RxD) from the analog differential signal (CAN_H , CAN_L) according to the first operating mode (SIC) and / or an analog differential signal (CAN_H, CAN_L) which was generated according to a second operating mode (FAST_TX), with which at least one other subscriber station (10; 20; 30) of the Bus system (1) sends signals (CAN_H, CAN_L) to the bus (40), wherein the reception mode setting module (25; 250; 2500) is connected between the reception module (222; 2220) and a connection (RXD) for outputting the digital reception signal (RxD) to the communication control device (22). Transmitting/receiving device (22; 220; 2200). Claim 1 , wherein the transmission module (221) is not designed to send a digital transmission signal (TxD) according to the second operating mode (FAST_TX) to the bus (40). Transmitting/receiving device (22; 220; 2200). Claim 1 or 2 , wherein the transmission module (222; 2220) is designed to generate the analog differential signals (CAN_H, CAN_L) according to the first operating mode (SIC) for all communication phases (451, 452) of a message (46) with the same physical layer (451_P). , and wherein the analog differential signals (CAN_H, CAN_L) were generated according to the second operating mode (FAST_TX) for two communication phases (451, 452) of a message (45; 47) with different physical layers (451_P; 452_P). Transmitting/receiving device (22) according to one of the Claims 1 until 3 , wherein the reception module (222; 2220) has a receiver (2221; 2222) for evaluating the differential signals (CAN_H, CAN_L) received from the bus (40) with a first reception threshold (T1) or with a second reception threshold (T3), which differs from the first reception threshold (T1), wherein the reception mode setting module (25) is designed to set the receiver (2221; 2222) for evaluation with the first reception threshold (T1) when the differential received from the bus (40). Signals (CAN_H, CAN_L) were generated according to the first operating mode (SIC), and wherein the reception mode setting module (25) is designed to set the receiver (2221; 2222) for evaluation with the second reception threshold (T3) if the Bus (40) received differential signals (CAN_H, CAN_L) were generated according to the second operating mode (FAST_TX). Transmitting/receiving device (22; 220; 2200) according to one of Claims 1 until 3 , wherein the reception module (222; 2220) has a first receiver (2221) for generating the digital reception signal (RxD) by evaluating the differential signals (CAN_H, CAN_L) received from the bus (40) with a first reception threshold (T1), and a second receiver (2222; 2223) for generating the digital received signal (RxD) by evaluating the differential signals (CAN_H, CAN_L) received from the bus (40) with a second reception threshold (T2; T3), which differs from the first reception threshold ( T1) differs. Transmitting/receiving device (22). Claim 5 , wherein the reception mode setting module (25) is designed to activate the first receiver (2221) and deactivate the second receiver (2222) when the differential signals (CAN_H, CAN_L) received from the bus (40) according to the first operating mode (SIC) were generated, and wherein the reception mode setting module (25) is designed to activate the second receiver (2222). and deactivate the first receiver (2221) when the differential signals (CAN_H, CAN_L) received from the bus (40) were generated according to the second operating mode (FAST_TX). Transmitting/receiving device (22; 220; 2200). Claim 5 , wherein the first receiver (2221) and the second receiver (2222; 2223) are designed and / or arranged to simultaneously evaluate the differential signals (CAN_H, CAN_L) received from the bus (40). Transmitting/receiving device (220; 2200). Claim 7 , wherein the reception mode setting module (250; 2500) has at least one module (253) for logically ANDing the signal output from the first receiver (2221) and the signal output from the second receiver (2222), the output of the at least a module (253) is connected to the connection (RXD) for outputting the digital received signal (RxD) to the communication control device (22). Transmitting/receiving device (22) according to one Claims 1 until 7 , wherein the reception mode setting module (25) has a protocol controller (251) which is designed to evaluate the digital reception signal (RxD), whether the differential signals (CAN_H, CAN_L) received from the bus (40) according to the second operating mode (FAST_TX) was generated or not, and a state machine (252) for evaluating whether the receiving module (222; 2220) is used to evaluate the differential signals (CAN_H, CAN_L) received from the bus (40) according to the evaluation result of the protocol controller ( 251), wherein the reception mode setting module (25) is designed, the reception module (222; 2220) for evaluating the differential signals (CAN_H, CAN_L) received from the bus (40) according to the evaluation result of the protocol controller (251) to be set if the receiving module (222; 2220) is not set to evaluate the differential signals (CAN_H, CAN_L) received from the bus (40) in accordance with the evaluation result of the protocol controller (251). Transmitting/receiving device (2200) according to one Claims 1 until 3 , or 5 or 7 or 8, wherein the reception mode setting module (2500) also has an interface module (254) which is connected between the transmission module (221) and a connection (TXD) for outputting the digital transmission signal (TxD) of the communication control device (22). is connected to the transmitter module (221), and wherein the interface module (254) is designed to evaluate whether the differential signals (CAN_H, CAN_L) received from the bus (40) were generated according to the second operating mode (FAST_TX) or not, and for switching the transmitter module (221) in such a way that the transmitter module (221) cannot transmit on the bus (40) if the evaluation shows that the differential signals (CAN_H, CAN_L) received by the bus (40) correspond to the second operating mode (FAST_TX) were generated. Transmitting/receiving device (2200). Claim 10 , wherein the interface module (254) is designed to generate a digital received signal (RxD) from the differential signals (CAN_H, CAN_L) received from the bus (40), which were generated according to the second operating mode (FAST_RX). Subscriber station (20) for a serial bus system (1), with a transmitting/receiving device (22; 220; 2220) according to one of the preceding claims, and a communication control device (21) for controlling communication in the bus system (1) and for generating a digital transmission signal (TxD) for the transmission module (221). Subscriber station (20). Claim 12 , wherein the subscriber station (20) is designed for communication in a bus system (1), in which exclusive, collision-free access of a subscriber station (10, 20, 30) to the bus (40) of the bus system (1) is guaranteed at least temporarily . Method for receiving differential signals (CAN_H, CAN_L) in a serial bus system (1), the method being carried out with a transmitting/receiving device (22; 220; 2200) which is used to send and/or receive signals in a serial bus system (1). Bus system (1) has a transmission module (221), a reception module (222; 2220) and a reception mode setting module (25; 250; 2500), wherein the transmission module (221) for sending a digital transmission signal (TxD) of a communication control device (22) is designed as an analog differential signal (CAN_H, CAN_L) according to a first operating mode (SIC) on a bus (40) of the bus system (1) in order to send a message to at least one other subscriber station (10; 20; 30) of the bus system (1). (46), and wherein the method comprises the steps of receiving, with the receiving module (222; 2220), signals (CAN_H, CAN_L) from the bus (40), Generate, with the reception module (222; 2220), a digital reception signal (RxD) from the analog differential signal (CAN_H, CAN_L) according to the first operating mode (SIC) using a predetermined first reception threshold (T1), setting, with the reception mode Setting module (25; 250; 2500), the operating mode (SIC; FAST_RX) of the reception module (222; 2220), so that the reception module (222; 2220) receives a digital reception signal (RxD) from the analog differential signal (CAN_H, CAN_L). the first operating mode (SIC) and / or an analog differential signal (CAN_H, CAN_L) that was generated according to a second operating mode (FAST_TX), with which at least one other subscriber station (10; 20; 30) of the bus system (1) Sends signals (CAN_H, CAN_L) to the bus (40) and forwards them to the reception mode setting module (25; 250; 2500), which is between the reception module (222; 2220) and a connection (RXD) for outputting the digital reception signal (RxD) is connected to the communication control device (22), of the digital received signal (RxD) to the communication control device (22).

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