Apparatus for subscriber stations of a serial bus system and method for communicating in a serial bus system

Abstract

An apparatus (12; 32) for a serial bus system (1) and a method for communicating in the serial bus system (1) are provided. The apparatus (12; 32) includes a transmitting block (121) for serially transmitting a digital transmission signal (TxD) generated by a communication control device (12) onto a bus (40) of the bus system (1) as a signal (VDIFF) for exchanging messages (45) between user stations (10, 20, 30) of the bus system (1), in which at least one first communication phase (451, 453) and a second communication phase (452) are used for exchanging messages (45; 46) between user stations (10, 20, 30) of the bus system (1), and a receiving block (122) for serially receiving the signal (VDIFF) from the bus (40) and using... The system includes a digital receive signal (RxD) generated based on the signal (VDIFF) received from the bus (40) and the digital receive signal (RxD) serially output to the communication control device (12), and an operation type switching module (15; 35) for evaluating at least one signal (TxD, RxD, TC_S) received by or sent to the communication control device (12) in relation to the following signaling, namely, the operation type switching module (15; 35) should switch the transmitting block (121) and / or the receiving block (122) to an operation type (B_451_W) for serially transmitting the wake-up mode (125) to the bus (40).

Description

TECHNICAL FIELD

[0001] The present application relates to an apparatus for a subscriber station of a serial bus system and to a method for communication in a serial bus system, which operates both with high data rates and high fault tolerance and with reduced energy consumption and is cost-advantageous. BACKGROUND

[0002] For communication between sensors and control devices, for example in a vehicle, bus systems are usually used in which data is transmitted as messages in the ISO 11898-1 :2015 standard, which is the CAN protocol specification using CAN FD. These messages are transmitted via a bus between bus subscribers, for example sensors, control devices, transmitters, etc., of the bus system.

[0003] In order to be able to transmit data at higher bit rates than in CAN, an option for switching to a higher bit rate within a message is provided in the CAN FD message format. In such a technique, the maximum possible data rate is increased to values of more than 1 MBit / s by using a higher clock rate in the data field area. Such a message is also referred to below as a CAN FD frame or CAN FD message.

[0004] In order to transmit data from a transmitting bus subscriber to a receiving bus subscriber faster than in the case of CAN FD, a CAN FD successor bus system is currently being developed, which is referred to as CAN XL. In this case, in addition to the data rate in the data phase being higher than in the case of CAN FD, the useful data length implemented so far using CAN FD should also be increased by up to 64 bytes. However, the robustness advantages of a communication network based on CAN or CAN FD should also be retained even in the case of CAN XL. The reason for this is, inter alia, that CAN XL should support, in addition to pure data transmission via the CAN bus, further functions such as functional safety (Safety), data security (Security) and quality of service (QoS = Quality of Service). These are essential properties that are required in autonomous driving vehicles.

[0005] A large contribution to the robustness is provided by arbitration, in which it is determined which subscriber has exclusive, collision-free access to the bus in the subsequent data phase.

[0006] If the data rate during the data phase is further increased by switching the physical layer, then the operating type of the transmitting / receiving device that drives signals onto and receives signals from the bus should be switched. The physical layer corresponds to the bit transport layer or Layer 1 of the well-known OSI model (Open Systems Interconnection model). For robust data transmission, the switching between the various transmitting and receiving operating types must be as smooth as possible.

[0007] Furthermore, for bus systems that can operate in an energy-efficient manner, it is advantageous that only the technical infrastructure, particularly the vehicle's functions, are currently operational. ISO 11898-2:2016 describes the "partial networking" function (subnet operation) of a CAN network. In subnet operation, at least one user station can remain in sleep mode while other user stations continue to communicate. When the transmitting / receiving device (transceiver) of a CAN user station detects a dominant bit on the CAN bus, the CAN user station wakes up from its normal sleep state. The CAN user station wakes up from the subnet sleep state via a special wake-up message. In this case, subnet operation requires special transceiver and corresponding user station functions. According to ISO 11898-6, integrated into ISO 11898-2:2016, all wake-up messages must be sent in the classic CAN format. However, the transmitting / receiving device (transceiver) can also tolerate CAN FD frames without waking up.

[0008] Transmitters / receivers with selective wake-up capabilities are significantly more expensive than others due to their integrated protocol controller for recognizing individual wake-up messages determined for the user station. If such a transmitter / receiver is also required to be usable in a CAN XL network, it becomes even more expensive. This is because, for example, a first transmitter / receiver switching to an arbitration phase operation mode cannot reliably recognize the level of a second transmitter / receiver switching to a data phase operation mode. Without corresponding measures, this will lead to communication errors, resulting in a reduction in the net data rate that can be transmitted. Implementing error mitigation measures complicates the CAN protocol, thus increasing the cost of the user station. Summary of the Invention

[0009] Therefore, the object of the present invention is to provide an apparatus for a user station in a serial bus system and a method for communication in a serial bus system, which solves the above-mentioned problems. In particular, an apparatus for a user station in a serial bus system and a method for communication in a serial bus system should be provided, wherein high data rates and increased useful data per frame can be achieved with high fault tolerance and low communication power consumption, while maintaining great flexibility during operation of the technical facilities using the bus system for communication in a cost-effective bus system.

[0010] This task is solved by an apparatus for a user station in a serial bus system having the features of claim 1. The apparatus comprises a transmitting block for serially transmitting digital transmitting signals generated by a communication control device onto the bus of the bus system as signals for exchanging messages between user stations in the bus system, wherein at least one first communication phase and a second communication phase are used in the bus system for exchanging messages between user stations; a receiving block for serially receiving the signals from the bus and for generating digital receiving signals based on the signals received from the bus and serially outputting the digital receiving signals to the communication control device; and an operation type switching module for evaluating at least one signal received by or sent to the communication control device with respect to the following signaling, namely, that the operation type switching module should switch the transmitting block and / or the receiving block to an operation type for serially transmitting wake-up modes onto the bus.

[0011] The device is designed so that communication on the bus will not be interfered with by waking up user stations in the bus system. To this end, the wake-up mode used by the device begins outside the transmitted frames. Thus, frames preceding the wake-up mode are not tampered with and remain valid frames. Furthermore, subsequent frames are not interfered with, but at most experience a delay.

[0012] Another advantage is that the device or the transmitting / receiving device (transceiver) can independently identify the wake-up mode without the need for an expensive protocol controller in the transmitting / receiving device (transceiver).

[0013] Furthermore, there is no need to add functionality to the user station's protocol controller, which uses this functionality to send invalid frames as a bit pattern to wake the user station from sleep mode. Such frames would complicate the CAN protocol, thereby increasing the cost of the protocol controller. Additionally, it would reduce the net data rate that can be efficiently transmitted in the bus system.

[0014] Furthermore, if the wake-up mode begins during the time between frames (interval break), the device is designed to ensure that the wake-up mode does not disrupt any frames. Conversely, if the wake-up mode begins during bus idle (IDLE) periods, the risk of other user stations on the bus system simultaneously starting to transmit is minimal.

[0015] Therefore, by utilizing the aforementioned device in the bus system, in particular, the arbitration known from CAN can be retained during the first communication phase, and the transmission rate can still be significantly improved again compared to CAN or CAN FD.

[0016] This facilitates net data rates of at least 5 Mbit / s to approximately 8 Mbit / s or 10 Mbit / s or higher. At a transmission rate of 100 Mbit / s, the length of a single bit is less than 100 ns. Furthermore, the size of useful data in the bus system can reach up to 4096 bytes per frame.

[0017] If at least one CAN user station that tolerates CAN FD is also used in the bus system, the method performed by the device, which is designed according to the ISO 11898-1:2015 standard, can also be used.

[0018] Advantageous further designs of the device are described in the dependent claims.

[0019] Possibly, the operation type switching module is designed to switch the sending block and / or the receiving block from the operation type used for sending the wake-up mode to another predetermined operation type among at least two operation types after the transmission of the wake-up mode ends, in order to resume operation for exchanging messages between user stations in the bus system, wherein the wake-up mode is used to wake up all dormant user stations in the bus system.

[0020] The operation type switching module can be designed to evaluate the signaling received digital transmit signal at the first connection end and / or the digital receive signal to be output at the second connection end and / or the modulated signal received at the third connection end.

[0021] It is conceivable that the operation type switching module is designed with respect to the signaling evaluation pulse width modulation signal. In this case, the operation type switching module may be designed with respect to at least one PWM symbol in and / or immediately following the signaling evaluation bit in the transmitted signal, the at least one PWM symbol signaling to the operation type switching module that the device should switch from a slow operation type for transmitting the transmitted signal to the bus to a fast operation type for transmitting the transmitted signal to the bus.

[0022] In a particular design, the operation type switching module may be designed to signal the operation type switching module with respect to at least one PWM symbol in the signaling evaluation bits of the transmitted signal, the at least one PWM symbol signaling the device to switch from a fast operation type for transmitting the transmitted signal to the bus to a slow operation type for transmitting the transmitted signal to the bus.

[0023] According to one embodiment, the operation type switching module is designed to evaluate the signaling of the last N PWM symbols in the transmitted signal before the operation type switching module should switch the device to a fast operation type for transmitting the transmitted signal on the bus, wherein the device switches to a fast operation type for transmitting the transmitted signal on the bus in the N PWM signals, where N is a natural number greater than or equal to 1.

[0024] According to one embodiment, the operation type switching module is designed to evaluate the transmission signal with respect to the signaling when the device switches to a fast operation type, in which the device is not a sender of messages on the bus, wherein the device is designed not to send the signaling on the bus.

[0025] According to one design, the operation type switching module is designed to send the wake-up mode onto the bus not upon recognition of the signaling, but after a predetermined time point of communication in the bus system. In this case, the predetermined time point of communication in the bus system—at which the operation type switching module should switch the transmit block and / or receive block to the operation type for serially sending the wake-up mode onto the bus—may be the beginning of an intermediate frame interval between two different frames used for exchanging messages on the bus, and during which no user station sends anything to the bus, wherein the intermediate frame interval has at least three bits.

[0026] The wake-up mode may have a level corresponding to the level of a first communication phase, in which the transmitting block and / or the receiving block is switched to a predetermined operating type among at least two operating types, and during the first communication phase, the recessive bus state in the signal can be overridden by a dominant bus state. Alternatively, the wake-up mode may have a level corresponding to the level of a second communication phase, in which the transmitting block and / or the receiving block is switched to a predetermined operating type among the at least two operating types, and during the second communication phase, a bus state different from the recessive and dominant bus states exists in the signal.

[0027] The duration of the wake-up mode can be longer than the length of other predetermined bit modes that may occur during normal communication on the bus.

[0028] Alternatively, the operation type switching module is designed to identify a wake-up mode in a signal received from the bus when the device is in a sleep operation type, wherein the operation type switching module is designed to switch the transmitting block and / or the receiving block to a predetermined operation type among at least two operation types in response to the identified wake-up mode, so as to resume operation for exchanging messages between user stations in the bus system, wherein the operation type switching module is designed to output a signal to the communication control device to wake up the sleep communication control device.

[0029] The aforementioned task is also solved by a communication control device for a user station in a serial bus system according to claim 15. The communication control device has a communication control module for generating a transmit signal to control communication between the user station and at least one other user station in the bus system, wherein at least one first communication phase and a second communication phase are used in the bus system for exchanging messages between user stations in the bus system, wherein the communication control module is also designed to serially receive a receive signal from a device that has serially transmitted the transmit signal onto the bus of the bus system and generates the receive signal based on signals subsequently received from the bus, and wherein the communication control module is also designed to set signaling for the device in at least one signal for a message transmitted by the communication control device or received by the device, i.e., the device should switch to an operating type for serially transmitting a wake-up mode onto the bus.

[0030] The communication control module can be designed to set the signaling to at least one PWM symbol of at least one signal sent by or received by the communication control device.

[0031] The communication control device may also have a connection terminal for transmitting a modulated operation type signaling signal along with the signaling to the device, the device being designed to transmit the signaling signal to the bus of the bus system.

[0032] Depending on the specific implementation variant, the bus state of the signal received from the bus in the first communication phase and the bus state of the signal received in the second communication phase are generated using different physical layers.

[0033] According to another specific implementation variation, the bus state of the signal received from the bus in the first communication phase has a longer bit time than the bus state of the signal received in the second communication phase.

[0034] In the first communication phase, it can be negotiated which user station of the bus system will obtain at least temporary exclusive, conflict-free access to the bus in the subsequent second communication phase.

[0035] The aforementioned device may be part of a user station in a serial bus system.

[0036] The aforementioned user station may be part of a bus system, which further includes a bus and at least two user stations interconnected via the bus, enabling the at least two user stations to communicate serially with each other. In this case, at least one of the at least two user stations is the user station previously described.

[0037] The aforementioned task is also solved by a method for communication in a serial bus system according to claim 23. This method is performed using an apparatus having a transmitting block for serially transmitting a digital transmitting signal generated by a communication control device onto the bus of the bus system as a signal, and having a receiving block and an operating type switching module. The apparatus performs the following steps: receiving the signal from the bus using the receiving block, the signal being based on the digital transmitting signal and using the signal to exchange messages between user stations in the bus system; generating a digital receiving signal using the receiving block based on the signal received from the bus, and serially outputting the digital receiving signal to the communication control device; and evaluating at least one signal received from or sent to the communication control device with respect to the following signaling: the operating type switching module should switch the transmitting block and / or the receiving block to an operating type for serially transmitting a wake-up mode onto the bus.

[0038] This method provides the same advantages mentioned above regarding the device and / or user station.

[0039] Other possible implementations of the invention include combinations of features or embodiments not explicitly mentioned in the descriptions above or below regarding the embodiments. Furthermore, those skilled in the art can add various aspects to the corresponding basic forms of the invention as improvements or additions.

[0040] Attached Figure

[0041] The invention will now be described in more detail with reference to the accompanying drawings and embodiments.

[0042] Figure 1 A simplified block diagram of the bus system according to the first embodiment is shown;

[0043] Figure 2 A diagram is shown illustrating the structure of a message that can be transmitted by a transmitting / receiving device of a user station in a bus system according to a first embodiment;

[0044] Figure 3 A simplified schematic block diagram of a user station in a bus system according to a first embodiment is shown;

[0045] Figure 4 The time variation process of bus signals CAN-XL H and CAN-XL L during the arbitration phase on the bus of the bus system according to the first embodiment is shown.

[0046] Figure 5 The time variation of the differential voltage VDIFF is shown, which is generated by... Figure 4 The bus signals CAN-XLH and CAN-XLL are obtained;

[0047] Figure 6 The time variation process of bus signals CAN-XLH and CAN-XLL during the data phase on the bus of the bus system according to the first embodiment is shown.

[0048] Figure 7 The time variation of the differential voltage VDIFF is shown, which is generated by... Figure 6 The bus signals CAN-XLH and CAN-XLL are obtained;

[0049] Figure 8 The time variation of the differential voltage VDIFF is shown, which is generated by bus signals CAN-XL H and CAN-XL L respectively from the arbitration phase and the data phase according to the first embodiment;

[0050] Figure 9 A state diagram showing the operating state of the transmitting / receiving device according to the first embodiment is shown;

[0051] Figure 10 A timing diagram illustrating the operational state of a transmitting / receiving device according to another embodiment is shown, which acts only as a receiver of frames from the bus during the data phase; and

[0052] Figure 11 A timing diagram of the operating state of a transmitting / receiving device according to a second embodiment is shown, which acts as both a transmitter of frames to the bus and a receiver of frames from the bus during the data phase.

[0053] In the accompanying drawings, unless otherwise specified, the same or functionally equivalent elements are given the same reference numerals. Detailed Implementation

[0054] As an example, Figure 1 Bus system 1 is shown, which is specifically designed for use with CAN bus systems, CAN FD bus systems, CAN XL bus systems and / or variations thereof, as described below. Bus system 1 can be used in vehicles (especially motor vehicles), aircraft, etc., or in hospitals, etc.

[0055] exist Figure 1 In the bus system 1, there are a large number of user stations 10, 20, and 30, each user station connected to a bus 40 having a first bus core line 41 and a second bus core line 42. The bus core lines 41 and 42 can also be referred to as CAN H and CAN L or CAN-XL H and CAN-XL L, and are used for electrical signal transmission after a differential level or dominant level has been coupled into the input or after a recessive level has been generated in the signal in the transmit state.

[0056] The signals 45 and 46 can be serially transmitted between the various user stations 10, 20, and 30 via bus 40. User stations 10, 20, and 30 are, for example, control devices, sensors, and display devices of a motor vehicle.

[0057] If an error occurs during communication on bus 40, such as Figure 1 As indicated by the jagged black arrow, error frame 47 (error flag) can be sent. Error frame 47 consists of six dominant bits. All other user stations 10, 20, and 30 will recognize these six consecutive dominant bits as a format error or a violation of the bit stuffing rule, which stipulates that a bit opposite to the five identical bits must be inserted after the five identical bits in messages 45 and 46.

[0058] Error messages 45 and 46 are acknowledged by the receiver via an acknowledgment bit, which is a dominant bit driven by the acknowledgment slot implicitly sent by the sender. Apart from the acknowledgment slot, the sender of messages 45 and 46 expects to always see the level it transmitted on bus 40. Otherwise, the sender recognizes a bit error and considers messages 45 and 46 invalid. The unsuccessful messages 45 and 46 are then repeated.

[0059] like Figure 1 As shown, user station 10 has a communication control device 11, a transmitting / receiving device 12, an operation type signaling module 14, and an operation type setting module 15. Conversely, user station 20 has a communication control device 21, a transmitting / receiving device 22, and an optional operation type signaling module 24. User station 30 has a communication control device 31, a transmitting / receiving device 32, an operation type signaling module 34, and an operation type setting module 35. The transmitting / receiving devices 12, 22, and 32 of user stations 10, 20, and 30 are directly connected to bus 40, even though this... Figure 1 It is not shown in the document.

[0060] Communication control devices 11, 21, and 31 are respectively used to control the communication between the corresponding user stations 10, 20, and 30 and at least one other user station among the user stations 10, 20, and 30 connected to the bus 40 via the bus 40.

[0061] The communication control device 11 creates and reads a first message 45, which is, for example, a modified CAN message 45. In this case, the modified CAN message 45 is constructed based on the CAN XL format and will refer to... Figure 2 A more detailed description of the CAN XL format.

[0062] The communication control unit 21 can be implemented as a conventional CAN controller according to ISO 11898-1:2015. The communication control unit 21 creates and reads a second message 46, such as a classic CAN message 46. The classic CAN message 46 is constructed according to the classic basic format, in which up to 8 data bytes can be contained within the message. Alternatively, the second message 46 is constructed as a CAN FD message, which can include up to 64 data bytes, and these data bytes are transmitted at a significantly faster data rate than in the case of the classic CAN message 46. In the latter case, the communication control unit 21 is implemented as a conventional CAN FD controller.

[0063] The communication control unit 31 can be implemented to provide CAN XL messages 45 or classic CAN messages 46 to the transmitting / receiving unit 32 as needed, or to receive these messages from the transmitting / receiving unit 32. The communication control unit 31 thus creates and reads either the first message 45 or the second message 46, where the first and second messages 44, 46 differ from each other due to their data transmission standards (i.e., CAN XL or CAN in this case). Alternatively, the second message 46 is constructed as a CAN FD message. In the latter case, the communication control unit 31 is implemented like a conventional CAN FD controller.

[0064] Apart from the differences, which will be described in more detail below, the transmitting / receiving device 12 can be implemented as a CAN XL transceiver. The transmitting / receiving device 22 can be implemented like a conventional CAN transceiver or a CAN FD transceiver. The transmitting / receiving device 32 can be implemented to provide or receive messages 45 according to the CAN XL format or messages 46 according to the current CAN basic format to the communication control device 31 as needed. The transmitting / receiving devices 12 and 32 can be implemented as additionally or alternatively as conventional CAN FD transceivers.

[0065] Through two user stations 10 and 30, messages 45 in CAN XL format can be generated and then transmitted, and such messages 45 can be received.

[0066] Figure 2Message 45 illustrates a CAN XL frame 450, which is transmitted by either transmitter / receiver 12 or transmitter / receiver 32. The CAN XL frame 450 is subdivided into different communication phases 451 to 453 for CAN communication on bus 40: arbitration phase 451, data phase 452, and end-of-frame phase 453. An intermediate frame interval (IFS) exists between two distinct frames 450, and this IFS has at least three bits. During this interval, an idle or standby state 410 occurs on bus 40, in which no user stations 10, 20, or 30 transmit anything to bus 40. The idle or standby state 410 is hereinafter referred to as standby state 410.

[0067] During the arbitration phase 451, user stations 10, 20, and 30 negotiate bit by bit, by means of identifiers, which user station 10, 20, and 30 wishes to send messages 45 and 46 with the highest priority, and thus obtain exclusive access to bus 40 of bus system 1 in the next time period for transmission in the subsequent data phase 452.

[0068] In data phase 452, useful data for CAN-XL frames or messages 45 is transmitted. Depending on the value range of the data length code, the useful data can have, for example, a value of up to 4096 bytes or greater. As previously mentioned, in data phase 452, during normal operation, only one of user stations 10, 20, and 30 is the sender of frame 450. Therefore, all other user stations 10, 20, and 30 are receivers of frame 450 and thus switch to receive operation mode.

[0069] In frame end phase 453, for example, a checksum of the data from data phase 452 may be included in the checksum field. This data includes padding bits, which are inserted as opposite bits by the transmission blocks of message 45 after a predetermined number of identical bits, particularly 10 or other numbers. Furthermore, at least one acknowledgment bit may be included in the end field of frame end phase 453. Additionally, a sequence of seven identical bits indicates the end of CAN XL frame 450. Optionally, at least one acknowledgment bit is used to inform user stations 10 and 30 whether an error was found in the received CAN XL frame 450 or message 45, as previously mentioned.

[0070] Therefore, user stations 10 and 30 of bus system 1 see at least 11 identical bits at the end of frame 450. These identical bits consist of the confirmation boundary bit at the end of frame 450, a sequence of 7 identical bits indicating the end of frame 450, and an intermediate frame interval (IFS) having at least three bits and causing a standby state 410 on bus 40.

[0071] In the arbitration phase 451 and the frame end phase 453, the physical layer is used as in CAN and CAN-FD.

[0072] An important point during phases 451 and 453 is the use of the known CSMA / CR method, which allows user stations 10, 20, and 30 to access bus 40 simultaneously without disrupting higher-priority messages 45 and 46. This allows for the relatively simple addition of other bus user stations 10, 20, and 30 to bus system 1, which is highly advantageous.

[0073] The CSMA / CR method requires the existence of a so-called recessive state on bus 40, which can be overridden by dominant states on bus 40 from other user stations 10, 20, and 30. In the recessive state, high-ohmic relationships dominate on each user station 10, 20, and 30, which, combined with parasitic elements in the bus circuitry, results in a longer time constant. This limits the maximum bit rate of the current CAN-FD physical layer to approximately 2 megabits per second in real-world vehicle applications.

[0074] The sender of message 45 (e.g., user station 10) only begins sending bits of data phase 452 onto bus 40 when user station 10, as the sender, wins the arbitration and thereby gains exclusive access to bus 40 of bus system 1. The sender may switch to a faster bit rate and / or other physical layer after a portion of switching phase 452, or only at the beginning of the subsequent data phase 453, i.e., at the start of the subsequent data phase 453.

[0075] Generally speaking, compared to CAN or CAN FD, the following different characteristics can be achieved in bus systems using CAN XL:

[0076] a) Adopt and, where necessary, adapt proven features responsible for the robustness and user-friendliness of CAN and CAN FD, particularly the frame structure with identifiers and arbitration based on the CSMA / CR method.

[0077] b) Increase the net data transfer rate to approximately 10 megabits per second.

[0078] c) Increase the size of the useful data per frame to approximately 2k bytes.

[0079] Figure 3The basic structure of a user station 10, comprising a communication control unit 11, a transmitting / receiving unit 12, an operation type signaling module 14, and an operation type setting module 15, is shown. The communication control unit 11 includes a communication control module 113, which can be located within or separate from module 14. The communication control module 113 is specifically a CAN protocol controller. The operation type setting module 15 includes an evaluation block 151, a receive threshold switching block 152, and a time measurement block 153. In the evaluation block 151, limit values ​​1511 and 1512 are used to evaluate which operation type the transmitting / receiving unit 12 should switch to and thus set that operation type. The evaluation block 151 can be designed as a comparator.

[0080] User site 30 is similar to Figure 3 The configuration shown is different, except that the operation type setting module 34 is not integrated into the transmitting / receiving device 32, but is separate from the communication control device 31 and the transmitting / receiving device 32. Furthermore, the operation type signaling module 34 is provided separately from the communication control device 11. Therefore, the user station 30 and the operation type setting module 35 will not be described separately. The functions of modules 14 and 15 described below are the same in their corresponding modules 34 and 35.

[0081] according to Figure 3 In addition to the communication control unit 11, the transmitting / receiving unit 12, and modules 14 and 15, the user station 10 also includes a microcontroller 13 and a system ASIC 16 (ASIC = Application-Specific Integrated Circuit). The user station's application software 131 can be executed in the microcontroller 13. The communication control unit 11 is assigned to the microcontroller 13. Furthermore, a wake-up mode 125 is stored in the storage device of the transmitting / receiving unit 12. Depending on the application, the wake-up mode 125 can be configured in the transmitting / receiving unit 12, particularly in its storage device. Alternatively, the wake-up mode 125 is permanently set in the transmitting / receiving unit 12.

[0082] The system ASIC 16 (ASIC = Application-Specific Integrated Circuit) can alternatively be a system base chip (SBC) on which multiple functions required for the electronic modules of the user station 10 are combined. In addition to the transmitting / receiving device 12, a power supply device 17 is also installed in the system ASIC 16 to supply power to the transmitting / receiving device 12. The power supply device 17 typically provides a 5-volt CAN_Supply. However, the power supply device 17 can provide other voltages with different values ​​as needed. Additionally or alternatively, the power supply device 17 can be designed as a current source.

[0083] The transmitting / receiving device 12 also includes a transmitting block 121 and a receiving block 122. Although the transmitting / receiving device 12 is always referred to below, the receiving block 122 may alternatively be located in a separate device outside of the transmitting block 121. The transmitting block 121 and the receiving block 122 can be constructed as in a conventional transmitting / receiving device 22. The transmitting block 121 may, in particular, have at least one operational amplifier and / or transistor. The receiving block 122 may, in particular, have at least one operational amplifier and / or transistor.

[0084] The transmitting / receiving device 12 is connected to bus 40, more specifically to its first bus line 41 for CAN_H or CAN-XL_H and its second bus line 42 for CAN_L or CAN-XL_L. The voltage supply for the energy supply device 17 of CAN_Supply, which supplies power, particularly voltage, to the first and second bus lines 41, 42, is made via at least one connection terminal 43. Connection to ground or CAN_GND is achieved via connection terminal 44. The first and second bus lines 41, 42 are terminated by terminating resistors 49.

[0085] The first and second bus cores 41 and 42 are connected in the transmitting / receiving device 12 not only to the transmitting block 121, also known as the transmitter, but also to the receiving block 122, also known as the receiver, though they are not shown for simplicity. Figure 3 The first and second bus cores 41 and 42 are also connected to module 15 in the transmitting / receiving device 12.

[0086] During the operation of bus system 1, transmitting block 121 can transfer the communication control device 11 with digital states 0 and 1 (in the transmission operation of transmitting / receiving device 12) during the transmission operation of transmitting / receiving device 12. Figure 3 (Illustratively illustrated) The transmit signal TXD or TxD is converted into corresponding signals Data_0 and Data_1 for bus cores 41 and 42, and these signals Data_0 and Data_1 are sent to bus 40 at the connection terminals for CAN_H and CAN_L or CAN-XL_H and CAN-XL_L, as shown below. Figure 4 As shown.

[0087] Receiver block 122 forms a data structure based on the bus signals received from bus 40 on CAN-XL_H and CAN-XL_L. Figure 5 The differential voltage VDIFF is converted into a receive signal RXD or RxD with digital states 0 and 1, such as... Figure 3 The illustration is as follows. For example... Figure 3 As shown, the receiving block 122 forwards the received signal RXD or RxD to the communication control device 11.

[0088] Furthermore, signaling can be exchanged between devices 11 and 12, particularly devices 12 and 14, via connection terminal RXD for receiving signal RxD and / or connection terminal TXD for transmitting signal TxD and / or optional connection terminal TC_S. Connection terminal TC_S can be an additional connection terminal. Alternatively, connection terminal TC_S is a standby connection terminal STB, also known as a standby connection terminal.

[0089] During normal operation, the transmitting / receiving device 12 always uses the receiving block 122 to listen for the transmission of data or messages 45, 46 on the bus 40, regardless of whether the transmitting / receiving device 12 is the sender of message 45.

[0090] according to Figure 4 The signals on CAN-XL_H and CAN-XL_L have dominant and recessive bus levels 401 and 402 in the aforementioned communication phases 451 and 453, as known from CAN. Because Figure 4 The signals CAN-XL_H and CAN-XL_L are formed on bus 40. Figure 5 The differential signal VDIFF shown is CAN-XL_H-CAN-XL_L. The bits of the differential signal VDIFF have a bit duration t_bt1.

[0091] from Figure 4 It can be seen that the transmitting block 121 drives the dominant state 402 of the differential signals CAN-XL_H and CAN-XL_L differently only in the aforementioned communication stages 451 and 453. Here, in the aforementioned communication stages 451 and 453, the bus level on bus 40 for the recessive state 401 is equal to, for example, a voltage Vcc of approximately 5V or half of CAN_Supply, i.e., 2.5V. In the recessive state 401, the bus level is not driven by the transmitting block 121, but is set by the terminating resistor 49. Conversely, the bus level on bus 40 for the dominant state 402 is approximately 1.5V for the signal CAN_XL_L and approximately 3.5V for the signal CAN_XL_H. Therefore, in Figure 4 and Figure 5 The example yields a differential voltage VDIFF between approximately 0V and 2V. Therefore, for voltage VDIFF = CAN-XL_H - CAN-XL_L, recessive state 401 (logic "1" for transmitting signal TxD) receives approximately 0V, while dominant state 402 (logic "0" for transmitting signal TxD) receives approximately 2.0V. Receiver block 122 can identify the state transition between states 401 and 402 in stages 451 and 453 using a receive threshold T_a, which is... Figure 5 As shown in the image.

[0092] exist Figure 5In the example, the receive threshold T_a of the receive block 122 is set to approximately 0.7V using the operation type setting module 15. In common transceiver modules or modules of the transmit / receive device 12, the receive threshold lies within a tolerance range between T_a_min and T_a_max, depending on the operating temperature, operating voltage, and manufacturing tolerances. Figure 8 As shown in the image.

[0093] In addition, according to Figure 5 A receive threshold T_c with a negative voltage value is set. For example, the negative voltage value of the receive threshold T_c is between -0.3V and -0.8V. However, even if the value of the receive threshold T_c is, for example, -0.4V, this value can be optimized according to the currently used CAN bus topology. Therefore, other values ​​of the negative voltage value can be considered, which can also be derived from... Figure 8 The value of the receiving threshold T_c is derived from the description. It is determined based on manufacturing tolerances and the effects of temperature and operating voltage.

[0094] Therefore, the run type setting module 15, especially its block 152, sets the receiving thresholds T_a and T_c for the receiving block 122 in stages 451 and 453.

[0095] Using the receive threshold T_c, receive block 122, particularly block 151 of the operation type setting module 15, can identify whether a negative voltage appears in the differential signal VDIFF in stages 451 and 453. If a negative voltage appears in the differential signal VDIFF, receive block 122 outputs a receive signal RxD = '0', even though the result should be RxD = '1' according to the receive threshold T_a specified in ISO 11898-2. This prevents stage 452 from incorrectly identifying the standby state 410 of the CAN bus 40 even when data of the CAN XL frame 450 is being transmitted.

[0096] The run type setting module 15, and in particular its evaluation block 151, can use a switching threshold T_c to identify a predetermined wake-up mode 125 in sleep state B_451_S. This will be referenced below. Figure 9 To describe in more detail.

[0097] Figure 6 and Figure 7 The data phase 452 is shown with Figure 4 and Figure 5 A similar time-varying process. Therefore, in data phase 452, the transmitting block 121 drives the bus states U_D0 and U_D1 of the differential signals CAN-XL_H and CAN-XL_L differently, respectively. Therefore, the signals CAN-XL_H and CAN-XL_L differ in data phase 452 from those according to... Figure 4 The regular signals on CAN_H and CAN_L are as described above.

[0098] The run type setting module 15, and in particular its switching block 152, sets the receiving thresholds T_d and T_c for the receiving block 122 in the data phase 452, which will be explained in more detail below.

[0099] according to Figure 8 Generally, it is established that the differential voltage VDIFF is obtained in communication phases 451 and 453 at the receiver of frame 450, between the maximum value 0.05V = VDIFF_401_max for the recessive state 401 and the minimum value 1.5V = VDIFF_402_min for the dominant state 402. Furthermore, according to... Figure 8 Generally, it is assumed that the receiving threshold T_a of receiving block 122 in evaluation block 151 lies between the minimum receiving threshold T_a_min of 0.5V and the maximum receiving threshold T_a_max of 0.9V. The value of the receiving threshold T_a is determined based on manufacturing tolerances and the effects of temperature and operating voltage. Therefore, if the differential voltage VDIFF is below 0.5V, such as... Figure 8 As shown on the left as an example, the bus level VDIFF_401 will definitely be read as "recessive". If the differential voltage VDIFF level is higher than 0.9V, the bus level will definitely be read as "dominant". If the differential voltage VDIFF level is between 0.5V and 0.9V, the level cannot be definitively identified as "recessive" or "dominant".

[0100] If the transmitting / receiving device 12, particularly its module 15, recognizes the end of the arbitration phase 451, then the transmitting / receiving devices 12, 22, and 32 in the user stations 10, 20, and 30 of the bus system 1 switch to the corresponding operating type for the data phase 452, as will be determined later based on... Figure 9 A more detailed explanation.

[0101] Figure 8 The right side shows the differential voltage VDIFF formed by signals Data_0 and Data_1, which the transmitting block 121 sends to bus 40 during the data phase 452 operation. Figures 6 to 8 In the example, the bus level on bus 40 for the Data_0 state (logic:='0') is approximately 3V for the signal CAN_XL_H and 2V for the signal CAN_XL_L. In data phase 452, the bus level U_D1 on bus 40 for the Data_1 state (logic:='1') is approximately 2V for the signal CAN_XL_H and 3V for the signal CAN_XL_L. Alternatively, a differential voltage VDIFF with other bus levels of + / -1V is possible. However, according to... Figure 6The 3V and 2V levels are symmetrical with the 2.5V center voltage at a 5V operating voltage. This symmetry helps reduce radiation that degrades signal quality on bus 40.

[0102] according to Figure 8 The right-hand portion, in the optional faster data phase 452 of bus states Data_0 and Data_1, corresponds to the binary data states 0 and 1 of the transmitted signal TXD, deriving bus states U_D0, U_D1 or differential voltages VDIFF_D0, VDIFF_D1. Figures 6 to 8 In the example, the minimum differential voltage VDIFF_D0_min of the Data_0 bit expected by the receiver or its receiving block 122 in data phase 452 is approximately 0.6V. Figures 6 to 8 In the example, the maximum differential voltage VDIFF_D1_max of the Data_1 bit is approximately -0.6V in data phase 452.

[0103] Therefore, the transmitting block 121 again drives the states of the differential signals CAN-XL_H and CAN-XL_L differently, as in the communication stages 451 and 453 described above. However, in the data stage 452, the two bus states U_D0 and U_D1 or the differential voltages VDIFF_D0 and VDIFF_D1 are driven symmetrically corresponding to the data states 0 and 1 of the transmitting signal TXD. Furthermore, the bus level used for the data state Data_0 in communication stages 451 and 453 is different from that of the data state Data_0 in communication stage 452. Also, the bus level used for the data state Data_1 in communication stages 451 and 453 is different from that of the data state Data_1 in communication stage 452.

[0104] As previously mentioned, in data phase 452, in addition to the receiving thresholds T_a and T_c of phases 451 and 453, receiving block 122 also uses a receiving threshold T_d. The nominal value of the receiving threshold T_d is approximately 0.0V. Therefore, the receiving threshold T_d lies between the maximum value of T_d_max = 0.1V and the minimum value of T_d_min = -0.1V. The value of the receiving threshold T_d is determined based on manufacturing tolerances and the effects of temperature and operating voltage.

[0105] The nominal differential voltage VDIFF_401 of the latent data state is 0V, falling within the range between T_d_max and T_d_min, and therefore cannot be explicitly identified when using the receive threshold T_d = 0.0V. However, the nominal differential voltage VDIFF_401 of the latent data state can be identified using the receive threshold T_a. The minimum differential voltage VDIFF_D0_min of the data state Data_0 is lower than T_a_max, and therefore cannot be explicitly identified when using the receive threshold T_a. However, the minimum differential voltage VDIFF_DO_min of the data state Data_0 can be identified using the receive threshold T_d.

[0106] Therefore, the operation type setting module 15 sets the reception thresholds T_a and T_c in stages 451 and 453. In stage 452, the operation type setting module 15 sets three reception thresholds T_a, T_d, and T_c. Based on the evaluation of the reception threshold T_c, the operation type setting module 15 can turn on or off at least one of the reception thresholds T_a and T_d, as shown in reference... Figure 9 A more detailed description.

[0107] Therefore, sending block 121 switches from the first run type in stages 451 and 453 to another run type in data stage 452, as shown in the reference. Figure 9 A more detailed explanation follows. In the first run type, bits have a bit duration t_bt1 and there are dominant and recessive bus states or bus levels. In the data stage 452 run type, bits have a bit duration t_bt2 and there are no dominant and recessive bus states or bus levels; instead, there are bus levels Data_0 and Data_1. The bit duration t_bt2 can be less than the bit duration t_bt1, such as... Figure 6 As shown in the diagram. Optionally, the bit durations t_bt2 and t_bt1 are the same.

[0108] In other words, based on Figure 4 , Figure 5 and Figure 6 In the first operating type of the left part, the transmitting block 121 generates a first data state (e.g., 0) of the transmitting signal TxD as a bus state 402 with different bus levels for the two bus lines 41 and 42 of the bus 40, and generates a second data state (e.g., 1) of the transmitting signal TxD as a bus state 401 with the same bus level for the two bus lines 41 and 42 of the bus 40.

[0109] Furthermore, for the time variation process of signals CAN-XL_H and CAN-XL_L in the operation type including data phase 452, the transmitting block 121 at least partially drives the first and second data states 0 and 1 of the transmitting signal TxD, respectively, so that the two bus lines 41 and 42 of the bus 40 are formed. Figure 6 The bus levels on the right are Data_0 and Data_1.

[0110] The difference between the physical layer in communication phases 453 and 451 of CAN and the previously described physical layer in data phase 452 is that in data phase 452, the state Data_1 with differential voltage VDIFF_D1 is partially or completely driven by the transmitting block 121 or the transmitting / receiving device 12. In the case of a bit rate of, for example, 10 Mbit / s in data phase 452, the bit time t_bt2 = 100 ns.

[0111] Therefore, in Figure 6 In the example shown, the bit duration t_bt2 in data phase 452 is shorter than the bit duration t_bt1 used in arbitration phase 451 and frame end phase 453. Therefore, a higher bit rate is used in data phase 452 than in arbitration phase 451 and frame end phase 453. In this way, the transmission speed in bus system 1 can be further increased compared to the case of CAN FD.

[0112] Figure 9 The diagram illustrates the switching between communication phases 451 and 453 of the transmitting / receiving device 12, in which "slow operation type" B_451 or "slow mode" is used, and communication phase 452, in which "fast operation type" B_452_RX or B_452_TX (also known as "fast mode") and operation types B_451_S and B_451_W are used, as explained in more detail below. Furthermore, the configuration operation type B_420 of the transmitting / receiving device 12 can be set.

[0113] If switching condition S_20 exists, the transmitting / receiving device 12 can switch to configuration operation type B_420, as indicated by the arrow between operation type B_451 and operation type B_420. At least one communication setting can be made in configuration operation type B_420. For example, the values ​​of receive thresholds T_a, T_d, and T_c can be set, the value of the duration of communication in bus system 1 can be set, wake-up mode 125 can be set, limit values ​​1511 and 1512 can be set, at least one identifier can be set, or other settings can be made. The switchback condition S_21 from operation type B_420 to operation type B_451 can be that the transmit signal TxD is constant for a predetermined time t, for example, greater than 5 μs. The switchback condition S_21 ensures that user station 10 can re-engage in communication in bus system 1 after the predetermined time t.

[0114] The difference between operating types B_451, B_452_RX, and B_452_TX lies in how the logic (digital) signal TxD to be transmitted is driven onto bus 40 (CAN_L, CAN_H) as a differential voltage VDIFF, and how the differential voltage VDIFF is evaluated to generate the logic (digital) receive signal RxD. Additionally, the direction of at least one of the connection terminals RXD and TXD can optionally be switched to notify device 12 via connection terminals RXD and TXD that it will be switched to one of operating types B_420, B_451, B_451, B_451_S, B_451_W, B_452_RX, and B_452_TX. If connection terminals RXD and TXD operate in the same direction, differential transmission can be performed via connection terminals RXD and TXD.

[0115] In operation type B_451, the transmitting / receiving device 12 is configured to transmit and receive signals, as shown in the reference. Figure 4 , Figure 5 and Figure 8 The left-hand side describes this. In operation type B_451, the transmitting / receiving device 12 uses VDIFF = +2V to drive the bits to be transmitted as logic '0', but does not drive the bits to be transmitted as logic '1' at all. The bus level of VDIFF = 0V is set by terminating resistor 49, as specified in ISO 11898-2. The transmitting / receiving device 12 also uses the receive threshold T_a specified in ISO 11898-2 to distinguish between VDIFF = +2V and VDIFF = 0V to generate the receive signal RxD. Additionally, the receive threshold T_c is used.

[0116] If arbitration of frame 450 is completed, it is determined which of user stations 10, 20, and 30 is permitted to transmit its frame 450 onto bus 40 in the subsequent data phase 452. Depending on whether a switching condition S52_1 or S52_3 exists, the transmitting / receiving device 12 switches to operating type B_452_RX or operating type B_452_TX at the end of arbitration phase 451. If user station 10 lost the previous arbitration or did not participate in the arbitration, user station 10 is not the sender of frame 450 in data phase 452, thus switching condition S52_1 exists. Conversely, if user station 10 won the previous arbitration, user station 10 is the sender of frame 450 in data phase 452, thus switching condition S452_3 exists.

[0117] In operation type B_452_RX, the operation type setting module 15 has configured the transmitting / receiving device 12 to receive signals, as shown in the reference. Figure 6 , Figure 7 and Figure 8 The right side of the description is as follows. In operating type B_452_RX, the transmitting / receiving device 12 does not drive the bus 40 and uses a 0V receive threshold T_d to distinguish between levels VDIFF = +1V and VDIFF = 1V. The connection terminal TXD can be set to TXD = 1. Alternatively, the opposite receive signal RxD can be sent to device 11 via the connection terminal TXD. If the transmitting / receiving device 12 detects the end of data phase 452, a switchback condition S52_2 exists, causing the operating type setting module 15 to switch the transmitting / receiving device 12 back to operating type B_451. In error conditions, such as if no edge change is received from the bus 40 for a predetermined time t in operating type B_452_RX, the evaluation module 151 of the operating type setting module 15 identifies the switchback condition SO. The switchback condition SO is identified by the evaluation block 151 comparing the predetermined time t with the shutdown time T_O, for example, which can be set to... If the switchback condition SO exists, the operation type setting module 15 switches the transmitting / receiving device 12 back to operation type B_451 by means of its receiving threshold switching block 152.

[0118] In operation type B_452_TX, the operation type setting module 15 has already configured the transmitting / receiving device 12 to transmit and receive signals, as shown in the reference. Figure 6 , Figure 7 and Figure 8As described in the right-hand section. In operating type B_452_TX, the transmitting / receiving device 12 uses VDIFF = -1V to drive the bits of the transmitting signal TxD to be transmitted as logic "1" onto bus 40. Conversely, the transmitting / receiving device 12 uses VDIFF = +1V to drive the bits of the transmitting signal to be transmitted as logic "0" onto bus 40. The receiving block 122 is set up as in operating type B_452_RX. Alternatively, the opposite transmitting signal TxD can be sent to device 12 via the connection terminal RXD. If the transmitting / receiving device 12 detects the end of data phase 452, a switchback condition S52_4 exists, causing the operating type setting module 15 to switch the transmitting / receiving device 12 back to operating type B_451. In error conditions, for example, if the signal TxD remains constant for a period exceeding a predetermined duration T1 in operating type B_452_TX, the evaluation module 151 of the operating type setting module 15 identifies the switchback condition S1. The cutback condition S1 is identified by comparing the predetermined time t with the shutdown time T_O in evaluation block 151. The shutdown time T_O can be set, for example, to... If the switchback condition S1 exists, the operation type setting module 15 switches the transmitting / receiving device 12 back to operation type B_451 by means of its receiving threshold switching block 152.

[0119] If the functionality of user station 10 is not required in the current operation of bus system 1, energy can be saved. For this purpose, bus system 1 can use the system controller to determine which user stations 10, 20, and 30 should hibernate and which should be activated or woken up. The decision regarding which user stations 10, 20, and 30 should hibernate is sent via bus 40 in messages 45 and 46. Local software 131 evaluates these messages 45 and 46. If user station 10 should hibernate, that is, if the transmitting / receiving device 12 should switch to operating type B_451_S "Hibernate until wake-up mode is recognized" (hibernate), the process is as follows. User stations 10, 20, and 30 are woken up via wake-up mode 125, as described below.

[0120] Software 131 can signal the transmitting / receiving device 12 to switch to operating type B_451_S, and disable the communication control device 11, and if necessary, the microcontroller 13. This state of the user station 10 is also called "entering hibernation". As a result, when the switching condition S51_1 exists, the transmitting / receiving device 12 uses module 15 to switch to operating type B_451_S. Operating type B_451_S can also be called operating type "hibernation until wake-up mode is recognized".

[0121] To switch the transmitting / receiving device 12 to operating type B_451_S, the software 131 in the user station 10 can perform the following: The software 131 can directly control the connection terminal (pin) of the operating type signaling module 14. Alternatively, the software 131 can instruct the communication control device 11, particularly the communication control module 113 or module 14, to control the transmitting / receiving device 12. In the latter case, the operating type signaling module 14 also signals a switch to operating type B_451_S, i.e., "sleep until wake-up mode is recognized."

[0122] In this embodiment, a pulse driven by the communication control module 113 or module 14 signals the module 15 on the RxD line between devices 11 and 12 to notify that the operating type of the transmitting / receiving device 12 will be switched to operating type B_451_S. Therefore, device 11 reverses the transmission direction at the RXD connection end to signal that the operating type of the transmitting / receiving device 12 will be switched to operating type B_451_S. Therefore, instead of a single pulse for switching from data phase 452 to frame end phase 453, a double pulse can be used to signal the module 15 that the transmitting / receiving device 12 should switch to operating type B_451_S.

[0123] In operation type B_451_S "Sleep until wake-up mode is recognized" (sleep), the transmitting / receiving device 12 does not drive the bus 40. The transmitting / receiving device 12 outputs a constant receive signal RxD, for example, RxD = '1'. Once the transmitting / receiving device 12 recognizes the wake-up mode 125 through the operation type setting module 15, the operation type setting module 15 uses its block 151 to notify the microcontroller 13 and / or the communication control device 11, especially the module 14, to wake up the other parts of the sleep user station 10. For this purpose, the transmitting / receiving device 12, more precisely its block 151, inverts the receive signal RxD. Alternatively or additionally, the transmitting / receiving device 12 can signal the wake-up via its own wake-up output TC_S. Furthermore, if the module 15 recognizes the wake-up mode 125, there is a switchback condition S51_2. Therefore, the module 15 switches the transmitting / receiving device 12 back to operation type B_451 after the aforementioned wake-up signaling. The transmitting / receiving device 12 thus exits the operating state "sleep until wake-up mode is recognized." The user station 10 then attempts to integrate into the communication on the bus 40. For this purpose, the functionality of the user station 10 can be fully utilized again.

[0124] As wake-up mode 125, a constant level longer than that that might occur during normal operation of bus system 1 can be used, for example. For example, a constant level VDIFF = -1V with a predetermined length can be used. During normal operation, only the recessive level VDIFF = 0V can occur for an extended period, i.e., when bus 40 is in standby state 410. The permissible lengths of other levels during normal operation, i.e., VDIFF = +2V, VDIFF = -1V, or VDIFF = +1V, are limited by bit stuffing rules. Alternatively, any other wake-up mode 125 can be used. In particular, wake-up mode 125 is a bit pattern consisting of multiple different alternating levels.

[0125] A wake-up mode 125, characterized by a constant voltage level VDIFF = -1V and a predetermined length longer than that that might occur during normal operation of bus system 1, can be identified by module 15 using a third receive threshold T_c as follows. Each time the value falls below the threshold T_c, evaluation block 151 begins time measurement using time measurement block 153. For this purpose, time measurement block 153 has, for example, at least one RC element and / or a timer. If the threshold T_c is exceeded, the time measurement of time measurement block 153 is reset. When the time measurement exceeds a limit value 1511, wake-up mode 125 is identified. The limit value 1511 is selected such that it cannot appear in the data phase 452 of CAN XL frame 450. Optionally, the limit value 1511 is configurable. Thus, the limit value 1511 can be adapted to the bit rates set for communication phases 451 to 453 respectively in the configuration operation type B_420. Additionally or alternatively, different limit values ​​1511 can be specified in the transmitting / receiving device 12 for different bit rates.

[0126] Other wake-up patterns 125 are identified in other ways not described herein. For example, evaluation block 151 may evaluate whether a threshold T_c is exceeded or fallen below more than once. Alternatively, patterns that exceed or fall below the threshold T_c once or multiple times are possible.

[0127] Optionally, the transmitting / receiving device 12 may alternatively or additionally identify the edge on the transmit signal TxD from the device 11, particularly module 14, as wake-up mode 125. In this case, the switchback condition S51_2 is also satisfied, so that the device 12 switches from operating type B_451_S to operating type B_451 by means of its module 15, i.e., wakes up in this way.

[0128] Optionally, a switchback condition S2 is added to the operating type B_451_S (hibernation), which module 15, particularly its evaluation block 151, can recognize. In the case of user station 10, the result of switchback condition S2 is that user station 10 is woken up if communication on bus 40 stops for a predetermined time t. The stoppage of communication may be caused by interference. User station 10, which is hibernating in subnetwork operation, can then be woken up to maintain emergency operation of bus system 1. This also applies to other hibernating user stations of bus system 1. Regarding user station 10, device 12 switches from operating type B_451_S to operating type B_451 by means of its module 15 when switchback condition S2 is present.

[0129] Evaluation block 151 identifies a communication halt because no +1V, -1V, or +2V VDIFF level is observed within a predetermined time t. Therefore, each time one of these three levels is observed, evaluation block 151 restarts another time measurement in block 153. When the time measurement in block 153 reaches a predetermined limit value 1512, evaluation block 151 identifies a communication halt.

[0130] Alternatively, evaluation block 151 can restart the timing measurement of block 153 for only one of the three VDIFF levels (e.g., for level VDIFF = 2V = dominant), for example, only when level VDIFF = +1V is observed. Alternatively, evaluation block 151 can restart the timing measurement of block 153 for only two of the three VDIFF levels.

[0131] In principle, the wake-up mode 125, which should be used to wake up at least one dormant user station 10, 20, 30, can be sent by any of the currently active user stations 10, 20, 30. However, alternatively, user stations 10, 20, 30 can be deployed in the bus system 1 to perform the tasks of the system controller for the subnet. In the example below, user station 10 has the task of the system controller. Alternatively, if the system controller is unavailable, at least one of user stations 10, 20, 30 can be used as a backup system controller. This improves the failover protection of the bus system 1. In the example below, user station 30 is a backup station that takes over the system controller task from user station 10.

[0132] If necessary, user station 10, acting as the system controller, can signal its transmitting / receiving device 12 to switch to operating type B_451_S, i.e., enter sleep mode. Therefore, in this case, the signaling is not made via bus 40, but via at least one of the connection terminals RxD, TxD, and TC_S. This can be used when all other user stations in bus system 1 have entered sleep mode. If wake-up mode 125 should be sent via bus 40, the system controller, particularly device 11 and / or its module 14, signals the transmitting / receiving device 12 to switch to operating type B_451_W. Operating type B_451_W can also be referred to as the "transmit wake-up mode" operating type. If module 15 recognizes this signaling, switching condition S51_3 exists. Subsequently, the transmitting / receiving device 12 can directly switch to operating type B_451_W. Alternatively, it can switch to operating type B_451_W only after switching to operating type B_451 or B_452_TX.

[0133] In order to send wake-up mode 125, in this example, the transmit / receive device 12 of user station 10 is switched to operating type B_451_W. In another example, the transmit / receive device 32 can of course be switched to operating type B_451_W instead, as described above.

[0134] All user stations 10, 20, and 30 receive wake-up mode 125 from bus 40. This wakes up all currently dormant user stations in bus system 1. However, it is possible that not all user stations 10, 20, and 30 are needed for subsequent communication. In this case, the system controller (e.g., user station 10) will instruct those user stations in bus system 1 that remain dormant via bus 40 to switch their transmitting / receiving devices 22 and 32 back to operating type B_451_W, i.e., "dormant until a wake-up mode is recognized," by means of at least one message.

[0135] To switch the system controller's transmitting / receiving devices to operating type B_451_W, i.e., "transmit wake-up mode" (wake-up), and to wake up the system controller of the hibernating user station, particularly the software 131 in user station 10, the following operations can be performed: The system controller can directly manipulate the connection terminals (pins) of the associated operating type signaling modules 14, 24, and 34. Alternatively, the system controller can instruct the associated communication control devices 11, 21, and 31 (particularly communication control module 113 or module 14) to manipulate the associated transmitting / receiving devices 12, 22, and 32. In the latter case, the associated operating type signaling modules 14, 24, and 34 also signal the switch to operating type B_451_W, i.e., "transmit wake-up mode" (wake-up).

[0136] Therefore, the user station 10, as the system controller, will use the microcontroller 13, and in particular the application software 131 of the microcontroller, to directly control the connection terminal (pin) of the operation type signaling module 14 or to control the communication control device 11, and in particular the communication control module 113, thereby controlling the operation type signaling module 14 to send a signal notification by sending the wake-up mode 125.

[0137] Significantly, when the CAN bus 40 is in standby state 410, the operation type signaling module 14 begins executing signaling to switch to operation type B_451_S, i.e., "transmit wake-up mode" (wake-up). For example, this signaling begins immediately after the CAN message or frame 450 ends. In this case, the signaling begins with the start of the intermediate frame interval (IFS). The signaling is a single-stage signaling.

[0138] In this embodiment, during the data phase 452 of the transmitting / receiving device 12 when switching to operating type B_452_TX (data phase in the transmission direction), the connection terminals TXD and RXD for signals TxD and RxD are used to transmit the signaling signal to be transmitted from device 11 as a differential signal to the transmitting / receiving device 12. To switch from operating type B_452_TX to operating type B_451, the connection terminals TXD and RXD, or the signals TxD and RxD, are set to the same value "1" (switching condition S52_3). To switch from operating type B_452_TX to operating type B_451_W, the connection terminals TXD and RXD, or the signals TxD and RxD, are set to the same value "0" (switching condition S5_3).

[0139] Alternatively, a switching signal may be defined, which device 11 uses to notify the transmitting / receiving device 12 after receiving frame 450, i.e. after operating type B_452_RX (data phase in the receiving direction): the transmitting / receiving device 12 should switch to operating type B_451_W.

[0140] According to the second embodiment, device 11 signals to transmitting / receiving device 12 via an additional connection terminal TC_S that the operating mode of transmitting / receiving device 12 should be switched. Therefore, this signaling notification is not performed via connection terminal RXD as described in the previous embodiments.

[0141] When the transmitting / receiving device 12 switches to operating type B_451_S, the signaling for "sleep until wake-up mode is recognized" is executed by the operating type signaling module 14. When the transmitting / receiving device 12 switches to operating type B_451_W, the signaling for "transmit wake-up mode" is also executed by the operating type signaling module 14.

[0142] In this embodiment, the operation type signaling module 14 generates signaling for the operation type that the transmitting / receiving device 12 should switch to, wherein the signal is pre-modulated via the connection terminal TC_S, specifically pulse width modulation (PWM). A first pre-modulated signal via the connection terminal TC_S signals a switch from the current operation state to operation type B_451_S, i.e., "sleep until wake-up mode is recognized." A second pre-modulated signal via the connection terminal TC_S signals a switch from the current operation state to operation type B_451_W, i.e., "transmit wake-up mode."

[0143] For example, the following encoding can be used, and module 15 evaluates the encoding.

[0144] When the modulation signal is a PWM signal with more than 1 component (0 components), for example, using... Figure 10 As shown in PWM_D1, evaluation block 151 evaluates this as "entering and remaining in FAST state," that is, evaluating it as signaling to switch to operating type B_452_RX or operating type B_452_TX. Here, the value of the transmit signal TxD indicates whether the transmit / receive device 12 should switch to operating type B_452_RX or operating type B_452_TX. Module 15 only evaluates the transmit signal TxD used for state transition when the signaling, i.e., the PWM signal, begins.

[0145] When the modulation signal is a PWM signal with more than 1 component and more than 0 components, for example using... Figure 10 As shown in PWM_D0, evaluation block 151 evaluates this as "entering state 'send wake-up mode' (wake-up)", which is evaluated as signaling to switch to run type B_452_W.

[0146] If a static 0 or constant level 0 is present at the TC S connection end, evaluation block 151 evaluates this as "entering SLOW state", that is, as signaling to switch to run type B_451.

[0147] Alternatively, the signaling for the operating type that the transmitting / receiving device 12 should switch to can be executed in two stages. In other words, module 14 executes the signaling to the transmitting / receiving device 12 in two steps.

[0148] In the first step, module 14, in particular communication control module 113, signals to the transmitting / receiving device 12 during the transmission of frame 450 that the transmitting / receiving device 12 should not switch to arbitration operation type B_451 (SLOW) at the end of data phase 452, but should switch to operation type B_451_W "transmit wake-up mode". When transmitting frame 450, the transmitting / receiving device 12 switches to operation type B_452_RX (FAST_RX) or operation type B_452_TX (FAST_TX).

[0149] In the second step, which is executed after a predetermined time t following the execution of the first step, wake-up mode 125 is sent. Therefore, wake-up mode 125 is not sent immediately, but rather after a pulse is received, for example, on the TxD line or in the transmit signal TxD. Alternatively, wake-up mode 125 is sent after a predetermined time has elapsed, the predetermined time depending on the bit rate of at least one of communication stages 451 and 452. Setting the latter predetermined time is more difficult than the timing of sending or receiving a pulse on the TxD line or in the transmit signal TxD.

[0150] In the same way, module 14, in particular communication control module 113, can signal to the transmitting / receiving device 12 that the transmitting / receiving device 12 should switch to operating type B_451_S or operating type B_451_W.

[0151] Figure 10 and Figure 11 The third embodiment describes how device 11 signals to transmitting / receiving device 12 via connection TXD to notify that the operating type of transmitting / receiving device 12 should be switched. Therefore, this signaling notification is not performed via connection RXD or TC_S as described in the previous embodiments. Furthermore, this signaling notification is performed in two stages.

[0152] Figure 10 The following situation is illustrated during time t: a transmit signal TXD_RX is sent at the connection end TXD. As a result, the transmit / receive device 12 switches to operating type B_452_RX in data phase 452 and therefore acts only as a receiver of frames 450 from bus 40 during data phase 452. Figure 10 The various stages of frame 450 are described above the transmitted signal TXD_RX. Figure 10 Below the transmit signal TXD_RX, the operating type of the transmit / receive device 12 set during time t is shown.

[0153] Figure 11The following situation is illustrated during time t: a transmit signal TXD_TX is sent at the connection end TXD. Therefore, the transmit / receive device 12 switches to operating type B_452_TX during the data phase 452 of frame 450 and thus acts as a transmitter of frame 450 to bus 40 and a receiver of frame 450 from bus 40 during the data phase 452. Figure 11 Below the transmit signal TXD_TX, the operating type of the transmit / receive device 12 set during time t is shown.

[0154] exist Figure 10 The signals TXD_RX and Figure 11 In the signal TXD_TX, PWM encoding is used instead of NRZ encoding (NRZ = Non-Return-to-Zero). The transmitting / receiving device 12 identifies the TxD signal as PWM encoded through numerous edges based on the PWM encoding. This is the switching condition for the transmitting / receiving device 12 to switch to the operating type of the data phase 452. The first PWM symbol determines whether the transmitting / receiving device 12 must switch to operating type B_452_TX (FAST_TX) or operating type B_452_RX (FAST_RX) in bit AL1. As long as the TxD signal remains PWM encoded and therefore the transmitting / receiving device 12 frequently sees edges on the TxD signal, the transmitting / receiving device 12 remains in the PWM encoding state. Figure 10 The runtime type is B_452_RX (FAST_RX) or according to Figure 11 The runtime type is B_452_TX (FAST_TX).

[0155] Even in user stations that act solely as receivers (receiving nodes) during the data phase, the protocol controller sends PWM symbols to the associated transmitting / receiving devices during operation type B_452_RX (FAST_RX). However, these PWM symbols are not transmitted onto bus 40 by the transmitting / receiving devices in the receiving nodes.

[0156] Each bit of the transmitted signals TXD_RX and TXD_TX is transmitted as one or more PWM symbols. The symbol duration has a maximum length T. If a 0-phase or 0-component is longer than a 1-phase or 1-component in a PWM symbol, then the symbol is a DATA0 symbol, as shown in... Figure 10 and Figure 11 This is referred to as PWM_D0. If a 1-stage or 1-component is longer than a 0-stage or 0-component in a PWM symbol, then the symbol is a DATA1 symbol, as shown in... Figure 10 and Figure 11 It is referred to as PWM_D1 in Chinese.

[0157] Transmitting / receiving devices 12 and 32 are respectively designed to decode PWM symbols according to the above rules before transmitting signals TXD_RX and TXD_TX onto bus 40. Transmitting / receiving devices 12 and 32 are respectively designed to decode symbol PWM_D0 into an NRZ signal with a value of 0 and to decode symbol PWM_D1 into an NRZ signal with a value of 1.

[0158] according to Figure 10 and Figure 11 At least the transmitting / receiving device 12 uses a phase particularly suitable for the signaling with module 14 or device 11 as previously described during the transmission of CAN XL frame 450.

[0159] If the transmitting / receiving device 12 switches to operating type B_452_RX (FAST_RX), then the transmitting / receiving device 12 will not... Figure 10 The PWM symbol shown is sent to bus 40. Furthermore, communication control module 113 or module 14 ignores the levels of two bits AL1 and AH1; during the bit time of these two bits, the operating mode of the transmitting / receiving device 12 will be switched. This applies to the receiving node ( Figure 10 ) and sending node ( Figure 11 ).

[0160] During these phases, specifically the two-bit intervals of AL1 and AH1, the communication control module 113 or module 14 can signal the transmitting / receiving device 12 via a predetermined PWM symbol mode to notify the transmitting / receiving device 12 that its operating type should be switched according to a predetermined schedule. Through the successive setting modes of the PWM symbols, the communication control module 113 or module 14 signals the transmitting / receiving device 12 to notify it that after leaving the data phase operating type B_452_RX or B_452_TX (FAST_RX or FAST_TX), it should not enter the arbitration phase operating type B_451 (SLOW) but rather the operating type B_451_W "transmit wake-up mode" (wake-up). After the duration T_O has elapsed, the transmitting / receiving device 12 re-enters operating type B_451 (SLOW), as described above.

[0161] In the data phase 452, when the transmitting / receiving device 12 switches to the receiving node operating type B_452_RX (FAST_RX), it can be, for example, according to Figure 10Execute signaling. Instead of only sending DATA1 symbols, specifically PWM_D1, communication control module 113 or module 14 also sends at least one DATA0 symbol, specifically PWM_D0. Multiple DATA0 symbols, specifically PWM_D0, can be sent sequentially or distributed over time t. The transmitting / receiving device 12 marks or stores the pattern of the received DATA1 / DATA0 symbols, such that when operation type B_452_RX (FAST_RX) ends, i.e., in bit AH1, the transmitting / receiving device 12 switches to operation type B_451_W "transmit wake-up mode".

[0162] In a specific case of the above process, communication control module 113 or module 14 uses the last N PWM symbols of data phase 452 to transmit a predetermined symbol pattern, where N is a natural number greater than or equal to 1. Transmitting / receiving device 12 marks or stores the last N symbols in a shift register. Therefore, communication control module 113 or module 14 can signal to transmitting / receiving device 12 that the pattern has changed to 2. N A state or running type.

[0163] Figure 10 An example of the simplest case with N=1 is shown. Since the last PWM symbol is DATA0 or PWM_D0, the transmitting / receiving device 12 switches to the operating type B_451_W "transmit wake-up mode" in bit AH1. Conversely, if the last PWM symbol is DATA1 or PWM_D1, the transmitting / receiving device 12 switches to the operating type B_451 (SLOW).

[0164] In the data phase 452, when the transmitting / receiving device 12 switches to the transmitting node operating type B_452_TX (FAST_TX), it can be, for example, according to Figure 11 Execute signaling. In this case, communication control module 113 or module 14 uses bits AL1 and AH1. Bit AL1 is used to switch the transmitting / receiving device 12 from operating type B_451 (SLOW) to operating type B_451_TX (FAST_TX) or operating type B_451_RX (FAST_RX). Bit AH1 is used to switch the transmitting / receiving device 12 from operating type B_451_TX (FAST_TX) or operating type B_451_RX (FAST_RX) to operating type B_451 (SLOW). As mentioned above, the CAN protocol ignores the actual values ​​of bits AL1 and AH1 on bus 40. Therefore, communication control module 113 or module 14 signals the transmitting / receiving device 12 with a predetermined PWM symbol pattern during these stages, i.e., the bit time of two bits AL1 and AH1, to notify the transmitting / receiving device 12 that the operating type of the transmitting / receiving device 12 should be switched according to a predetermined pattern.

[0165] For example, the first PWM symbol sent to the transmitting / receiving device 12 by the communication control module 113 or module 14 is a DATA0 symbol, specifically PWM_D0, thereby causing the transmitting / receiving device 12 to switch from operating type B_451 (SLOW) to operating type B_451_TX (FAST_TX) in the AL1 bit. Once the transmitting / receiving device 12 switches to operating type B_451_TX (FAST_TX), it transmits a pattern with N PWM symbols, where N is a natural number greater than or equal to 1. If, for example, N = 4, then specifically a DATA1 symbol followed by three DATA0 symbols can be transmitted. If the transmitting / receiving device 12, specifically the evaluation block 151, recognizes this pattern shortly after switching to operating type B_451_TX (FAST_TX), then block 152 switches the transmitting / receiving device 12 at the end of operating type B_452_TX (FAST_TX), causing the transmitting / receiving device 12 to switch to operating type B_451_W "transmit wake-up mode".

[0166] A special case of the above process is that communication control module 113 or module 14 utilizes the last N PWM symbols of data phase 452, i.e., shortly before leaving operating type B_451_TX (FAST_TX), to send a specific symbol pattern. Transmit / receive device 12 marks or stores these last N symbols in a shift register. Therefore, communication control module 113 or module 14 can signal to transmit / receive device 12 that the process has switched to 2... N A state or running type.

[0167] Figure 11 An example is shown for the case where N=2. Since the last two PWM symbols are DATA1 or PWM_D1, the transmitting / receiving device 12 switches to operating type B_451_W "transmit wake-up mode" in bit AH1. Otherwise, the transmitting / receiving device 12 enters operating type B_451(SLOW).

[0168] By switching the aforementioned signaling type to the appropriate operating type based on the communication phase on the bus 40 via the transmitting / receiving device 12 of user station 10, interference and interruption of communication on bus 40 can be prevented very cost-effectively. As a result, the net data rate in bus system 1 can be further improved.

[0169] All previously described designs of devices 11, 12, 21, 22, 31, 32, modules 14, 24, 34, 15, 35, user stations 10, 20, 30, bus system 1, and the methods performed therein can be used individually or in all possible combinations. In particular, all features of the above embodiments and / or modifications thereof can be combined arbitrarily. Additional or alternative modifications are particularly conceivable.

[0170] Even though the invention has been described above using a CAN bus system as an example, it can be applied to any communication network and / or communication method where two distinct communication phases are used, in which the bus states generated for the different communication phases are different from each other. In particular, the invention can be used for the development of other serial communication networks, such as Ethernet and / or 100Base-T1 Ethernet, fieldbus systems, etc.

[0171] In particular, the bus system 1 according to the embodiment can also be a communication network in which data can be transmitted serially at two different bit rates. An advantageous, but not mandatory, premise is that, in the bus system 1, exclusive, conflict-free access to the common channel by a user station 10, 20, 30 is guaranteed at least for a specific time period.

[0172] The number and arrangement of user stations 10, 20, and 30 in the bus system 1 of these embodiments are arbitrary. In particular, user station 20 in bus system 1 can be omitted. One or more of user stations 10 or 30 may exist in bus system 1. It is conceivable that all user stations in bus system 1 are designed identically, i.e., only user station 10 or only user station 30 exists.

[0173] The number of receive thresholds T_c added to receive thresholds T_d or T_a can also be increased further than previously described. This can further improve the plausibility check of the detection of the current operating type of ongoing communication. However, the cost of evaluating the thresholds increases with the number of receive thresholds T_c that are connected.

[0174] The above variations for sending signals to the corresponding transmitting / receiving devices to notify the operating type can be combined in any way.

[0175] At least one of the previously described variants for identifying operating types can withstand time filtering to improve robustness with respect to electromagnetic compatibility (EMV) and resistance to electrostatic charging (ESD), pulses, and other interference.

Claims

1. A device (12; 32) for a serial bus system (1), the device having A transmitting block (121) is used to serially transmit a digital transmission signal (TxD) generated by the communication control device (12) onto the bus (40) of the bus system (1) as a signal (VDIFF) for exchanging messages (45) between user stations (10, 20, 30) of the bus system (1), in which at least one first communication stage (451, 453) and a second communication stage (452) are used for exchanging messages (45, 46) between user stations (10, 20, 30) of the bus system (1). The receiving block (122) is configured to serially receive the signal (VDIFF) from the bus (40) and generate a digital received signal (RxD) based on the signal (VDIFF) received from the bus (40), and serially output the digital received signal (RxD) to the communication control device (12). The operation type switching modules (15, 35) are used to evaluate at least one signal (TxD, RxD, TC_S) received by or sent to the communication control device (12) with respect to the following signaling, namely, the operation type switching modules (15; 35) should switch the transmitting block (121) and / or the receiving block (122) to the operation type (B_451_W) for serially transmitting the wake-up mode (125) on the bus (40). The operation type switching module (15; 35) is designed to send the wake-up mode (125) to the bus (40) not upon recognition of the signaling, but after a predetermined time point of communication in the bus system (1). The predetermined time point for communication in the bus system (1) is the start of the intermediate frame interval between two different frames (450) for exchanging messages (45) on the bus (40), at which time the run type switching module (15; 35) should switch the sending block (121) and / or the receiving block (122) to the run type (B_451_W) for serially sending the wake-up mode (125) to the bus (40), and no user station (10, 20, 30) sends anything to the bus (40) during the intermediate frame interval. The intermediate frame interval has at least three bits.

2. The apparatus (12; 32) according to claim 1. The operation type switching module (15; 35) is designed to switch the sending block (121) and / or the receiving block (122) from the operation type (B_451_W) used for sending the wake-up mode (125) to other predetermined operation types among at least two operation types (B_420; B_451; B_451_S, B_451_W; B_452_RX; B_452_TX) after the end of the transmission of the wake-up mode (125), so as to restore the operation for exchanging messages (45) between user stations (10, 20, 30) in the bus system (1), and The wake-up mode (125) is used to wake up all dormant user stations (10, 20, 30) of the bus system (1).

3. The apparatus (12; 32) according to claim 1 or 2, wherein the operation type switching module (15; 35) is designed to evaluate the digital transmit signal (TxD) received at the first connection (TXD) and / or the digital receive signal (RxD) to be output at the second connection (RXD) and / or the modulated signal received at the third connection (TC_S) with respect to the signaling.

4. The apparatus (12; 32) according to any one of the preceding claims, wherein the operation type switching module (15; 35) is designed to evaluate the pulse width modulation signal with respect to the signaling.

5. The apparatus (12; 32) according to claim 4, wherein the operation type switching module (15; 35) is configured to signal the operation type switching module (15; 35) to at least one PWM symbol in and / or immediately following the signaling evaluation bit (AL1) in the transmit signal (TxD), the at least one PWM symbol signaling to the operation type switching module (15; 35) that the apparatus (12; 32) should switch from a slow operation type (B_451) for transmitting the transmit signal (TxD) to the bus (40) to a fast operation type (B_452_RX, B_452_TX) for transmitting the transmit signal (TxD) to the bus (40).

6. The apparatus (12; 32) according to claim 4 or 5, wherein the operation type switching module (15; 35) is configured to signal the operation type switching module (15; 35) to the apparatus (12; 32) to switch from a fast operation type (B_452_RX, B_452_TX) for sending the transmission signal (TxD) to the bus (40) to a slow operation type (B_451) for sending the transmission signal (TxD) to the bus (40) with regard to at least one PWM symbol in the signaling evaluation bit (AH1) of the transmit signal (TxD).

7. The apparatus (12; 32) according to any one of claims 4 to 6. The operation type switching module (15; 35) is designed such that, before switching the device (12; 32) to a slow operation type (B_451) for sending the transmit signal (TxD) to the bus (40), the device (12; 32) switches to a fast operation type (B_452_RX, B_452_TX) for sending the transmit signal (TxD) to the bus (40) for the last N PWM symbols of the signaling evaluation of the transmit signal (TxD), during which the device (12; 32) switches to a fast operation type (B_452_RX, B_452_TX) for sending the transmit signal (TxD) to the bus (40). Where N is a natural number greater than or equal to 1.

8. The apparatus (12; 32) according to any one of the preceding claims. The operation type switching module (15; 35) is designed to evaluate the transmit signal (TxD) with respect to the signaling when the device (12; 32) switches to the fast operation type (B_452_RX), in which the device (12; 32) is not a sender of the message (45) on the bus (40), and The devices (12; 32) are designed not to send the signaling to the bus (40).

9. The apparatus (12; 32) according to any one of the preceding claims, wherein the wake-up mode (125) has a level corresponding to a first communication phase (451; 453, 451), in which the transmitting block (121) and / or the receiving block (122) switches to a predetermined operating type (B_451) among the at least two operating types (B_420; B_451; B_451_S, B_451_W; B_452_RX; B_452_TX), and during the first communication phase, the recessive bus state (401) in the signal (VDIFF) can be overridden by the dominant bus state (402).

10. The apparatus (12; 32) according to any one of claims 1 to 8, wherein the wake-up mode (125) has a level corresponding to a level of a second communication phase (452), in which the transmitting block (121) and / or the receiving block (122) switches to a predetermined operating type (B_452_RX; B_452_TX) among the at least two operating types (B_420; B_451; B_451_S, B_451_W; B_452_RX; B_452_TX), and during the second communication phase there is a bus state (U_D0, UD1) in the signal (VDIFF) that is different from the recessive and dominant bus states (401, 402).

11. The apparatus (12; 32) according to claim 9 or 10, wherein the duration of the wake-up mode (125) is longer than the duration of any other predetermined bit mode that may occur in normal communication on the bus (40).

12. The apparatus (12; 32) according to any one of the preceding claims. The operation type switching module (15; 35) is designed to identify the wake-up mode (125) in the signal (VDIFF) received from the bus (40) when the device (12; 32) is in a hibernation operation type (B_451_S). The operation type switching module (15; 35) is designed to switch the transmitting block (121) and / or the receiving block (122) to a predetermined operation type (B_420; B_451; B_451_S, B_451_W; B_452_RX; B_452_TX) in response to a recognized wake-up mode (125) to resume operation for exchanging messages (45) between user stations (10, 20, 30) in the bus system (1), and The operation type switching module (15; 35) is designed to output a signal to the communication control device (12; 32) to wake up the dormant communication control device (12; 32).

13. A communication control device (11) for a user station (10) in a serial bus system (1), the communication control device having A communication control module (113) is configured to generate a transmit signal (TxD) for controlling communication between the user station (10) and at least one other user station (10; 20; 30) of the bus system (1), wherein at least one first communication phase (451, 453) and a second communication phase (452) are used in the bus system (1) to exchange messages (45; 46) between the user stations (10, 20, 30) of the bus system (1). The communication control module (113) is also designed to serially receive a received signal (RxD) from a device (12; 32) that has serially transmitted the transmitted signal (TxD) to the bus (40) of the bus system (1) and generates the received signal (RxD) based on a signal (VDIFF) subsequently received from the bus (40). The communication control module (113) is also designed to set signaling for the device (12; 32) in at least one signal (TxD, RxD, TC_S) sent by the communication control device (12) or received by the device (12; 32) for messages (45; 46), namely, the device (12; 32) should switch to an operating type (B_451_W) for serially sending the wake-up mode (125) on the bus (40). The communication control module (113) is also designed to send the wake-up mode (125) to the bus (40) not when the signaling is recognized, but after a predetermined time point of communication in the bus system (1), wherein the predetermined time point of communication in the bus system (1) is the beginning of an intermediate frame interval between two different frames (450) for exchanging messages (45) on the bus (40), at which time the run type switching module (15; 35) should switch the sending block (121) and / or the receiving block (122) to a run type (B_451_W) for serially sending the wake-up mode (125) to the bus (40), and no user station (10, 20, 30) sends anything to the bus (40) during the intermediate frame interval, and wherein the intermediate frame interval has at least three bits.

14. The communication control device (11) according to claim 13, wherein the communication control module (113) is designed to set the signaling to at least one PWM symbol of at least one signal (TxD, RxD, TC_S) sent by the communication control device (12) or received by the device (12; 32).

15. The communication control device (11) according to claim 13 or 14, further comprising a connection for transmitting a modulated operation type signaling signal (TC_S) together with the signaling to the device (12; 32), the device being designed to transmit the transmission signal (TxD) to the bus (40) of the bus system (1).

16. The apparatus (11; 12; 32) according to any one of the preceding claims, wherein the bus state (401, 402) of the signal received from the bus (40) in the first communication phase (451; 453, 451) and the bus state (U_D0, U_D1) of the signal received in the second communication phase (452) are generated using different physical layers.

17. The apparatus (11; 12; 32) according to any one of the preceding claims, wherein the bus state (401, 402) of the signal received from the bus (40) in the first communication phase (451; 453, 451) has a longer bit time (t_bt1) than the bus state (U_D0, U_D1) of the signal received in the second communication phase (452).

18. The apparatus (11; 12; 32) according to any one of the preceding claims, wherein in the first communication phase (451; 453, 451) it is negotiated which user station (10, 20, 30) of the bus system (1) will obtain at least temporarily exclusive, conflict-free access to the bus (40) in the subsequent second communication phase (452).

19. A user station (10; 30) for a serial bus system (1), the user station having The communication control device (11; 31) according to any one of claims 13 to 18, and The apparatus (12; 32) according to any one of claims 1 to 12.

20. A bus system (1) having Bus (40), and At least two user stations (10; 20; 30) are interconnected via the bus (40) so that the at least two user stations can communicate serially with each other, and at least one of the at least two user stations (10; 30) is a user station (10; 30) according to claim 19.

21. A method for communication in a serial bus system (1), wherein the method is performed using means (12; 32), the means having a transmitting block (121) for serially transmitting a digital transmitting signal (TxD) generated by a communication control device (12) onto a bus (40) of the bus system (1) as a signal (VDIFF), and having a receiving block (122) and an operation type switching module (15; 35), wherein the means (12; 32) performs the following steps: The receiving block (122) is used to receive the signal (VDIFF) from the bus (40), the signal being based on the digital transmission signal (TxD) and the signal being used to exchange messages (45) between user stations (10, 20, 30) of the bus system (1). The receiving block (122) generates a digital receive signal (RxD) based on the signal (VDIFF) received from the bus (40), and serially outputs the digital receive signal (RxD) to the communication control device (12). The operation type switching module (15; 35) evaluates at least one signal (TxD, RxD, TC_S) received from or sent to the communication control device (12) with respect to the following signaling, namely, the operation type switching module (15; 35) should switch the transmitting block (121) and / or the receiving block (122) to the operation type (B_451_W) for serially transmitting the wake-up mode (125) on the bus (40). The wake-up mode (125) is sent to the bus (40) not when the signaling is identified, but after a predetermined time point of communication in the bus system (1), wherein the predetermined time point of communication in the bus system (1) is the beginning of an intermediate frame interval between two different frames (450) for exchanging messages (45) on the bus (40), at which time the run type switching module (15; 35) should switch the sending block (121) and / or the receiving block (122) to a run type (B_451_W) for serially sending the wake-up mode (125) to the bus (40), and no user station (10, 20, 30) sends anything to the bus (40) during the intermediate frame interval, and wherein the intermediate frame interval has at least three bits.

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