Subscriber station and method for deterministic communication in a serial bus system

Abstract

A subscriber station (10; 20; 30) and a method for deterministic communication in a serial bus system (1) are provided. The subscriber station (10; 20; 30) has a communication control device (11; 21; 31) for controlling communication between the subscriber station (10; 20; 30) and at least one other subscriber station (20; 30; 10) of the bus system (1) by generating messages (45; 46) based on a frame (450) and by sending the messages (45; 46) to a bus (40) of the bus system (1) and by evaluating at least one signal (VDIFF; RXD) received from a bus (40) of the bus system (1) based on the frame (450), in which frame (450) the bit time (t_bt1) in a first communication phase (451) can differ from a bit time (t_bt2) in a second communication phase (452), and a pause module (152) for evaluating at least one of the communication control device (11; 21;31) output status information (ST_A) regarding whether or not a predetermined frame (450_B) has been received from the bus (40), wherein the pause module (152) is configured to generate and output a transmission delay signal (TX_E) based on a result of its evaluation in order to delay or not delay the provision of a transmission message (1511A) to the communication control device (11; 21; 31);

Description

Technical field

[0001] The present invention relates to a subscriber station and a method for deterministic communication in a serial bus system. State of the art

[0002] For cost reasons, many vehicle manufacturers prefer bus systems to point-to-point connections. Increasingly higher data transmission rates are required for communication between technical devices, such as sensors and control units. In some bus systems, technical devices are required to communicate with each other, which, if necessary, should be able to switch between different communication standards and / or data transmission rates between the bus system's participating stations as needed.

[0003] Currently, Classical CAN and / or CAN FD are used for communication between devices in vehicles and / or other technical facilities, both of which are standardized in the international standard ISO11898-1:2015.

[0004] In CAN bus-based communication, a frame is used to generate a transmission signal. This frame is divided into an arbitration phase and a data phase. During the arbitration phase, the bus system's subscriber stations negotiate which of the bus system's subscriber stations will receive exclusive access to the bus in the subsequent data phase and will then be permitted to send its data over the bus. In the data phase, the bits of the transmission signal are generated and sent over the bus with a shorter bit time for CAN FD and CAN XL than in the arbitration phase. Therefore, the bits are generated and sent over the bus at a higher bit rate during the data phase.

[0005] CAN FD is initially deployed by most vehicle users at a data bit rate of 2 Mbps and an arbitration bit rate of 500 kbit / s. So-called CAN SIC transceivers enable the use of CAN FD at up to 8 Mbps.

[0006] CAN XL, which is compatible with CAN FD and specified in ISO 11898-1, can also be used. With the help of SIC and SIC XL transceivers, bit rates of up to 8 Mbit / s and 20 Mbit / s, respectively, are possible in the data phase of CAN XL. However, even with CAN XL, the bit rate remains at approximately 500 kbit / s in the arbitration phase to enable arbitration. Furthermore, CAN XL supports payload lengths of up to 2048 bytes. The use of CAN XL in real products is currently beginning. This means that high data transmission rates are already feasible in a vehicle bus system.

[0007] However, for the operation of autonomous or semi-autonomous vehicles, an important requirement is that predetermined maximum reception delays are maintained for individual transmitted frames. Such delays are also called worst-case delays. This means that a frame must arrive at the receiving station (receiving node) no later than the worst-case delay. Delays can arise, for example, from other frames or signals occupying the bus.

[0008] Within a bus system, this requirement can be solved using deterministic bus access.

[0009] For this type of bus access, the 10BASE-T1S Ethernet transceiver, which has been standardized by the IEEE, uses a method called PLCA (Physical Layer Collision Avoidance). In PLCA, each node has a node number. All nodes transmit in sequence. This is referred to in the literature as Round Robin (RR) scheduling. The PLCA method also requires a master node (subscriber station). At the beginning of a cycle, the master node sends a so-called BEACON signal, which marks the start of the cycle. Each node is permitted to send one frame in each cycle. The PLCA method offers determinism and allows the communication bandwidth to be fairly distributed among all nodes. However, a disadvantage is that a master node is indispensable, even if this poses a risk to functional safety. Another disadvantage is that configuring the individual nodes with node numbers results in considerable complexity.

[0010] Arbitration in CAN-based bus systems uses the CSMA / CR (CR = Collision Resolution) method at the beginning of the frame, which resolves transmit collisions on the bus. Collision resolution is based on the frame's identifier (ID). The frame with the highest priority identifier (ID) prevails on the bus. This corresponds to strict-priority scheduling. This is currently sufficient for many use cases in autonomous vehicles. However, arbitration is not initially suitable for use cases that require deterministic bus access.

[0011] In some cases, this problem can be solved by selecting a higher bit rate on the CAN bus than required, so that the CAN bus is only utilized at, say, 50% capacity. However, this severely limits the net data rate. In any case, the possible net data rate cannot be achieved at maximum bus utilization. Disclosure of the invention

[0012] Therefore, it is an object of the present invention to provide a subscriber station and a method for deterministic communication in a serial bus system that solve the aforementioned problems. In particular, a subscriber station and a method for deterministic communication in a serial bus system are to be provided in which, even when different communication standards and bit rates are used in the bus system, deterministic bus access can be implemented and guaranteed for individual subscriber stations as needed, even at maximum bus utilization, in a straightforward, cost-effective, and secure manner.

[0013] This object is achieved by a subscriber station for deterministic communication in a serial bus system having the features of claim 1. The subscriber station has a communication control device for controlling communication between the subscriber station and at least one other subscriber station of the bus system by generating a message based on a frame and by sending the message to a bus of the bus system, as well as by evaluating at least one signal received from a bus of the bus system based on the frame, in which frame the bit time in a first communication phase can differ from a bit time in a second communication phase, and a pause module for evaluating at least one item of status information output by the communication control device with regard to whether a predetermined frame has been received from the bus or not, wherein the pause module is designedto generate and output a transmission delay signal based on a result of its evaluation in order to delay or not delay the provision of a transmission message to the communication control device, wherein the transmission message is to be sent by the communication control device as a message on the bus.

[0014] The design of the described subscriber station enables deterministic bus access and achieves the maximum possible net data rate at maximum bus utilization. Advantageously, the described subscriber station allows for 100% CAN bus utilization while simultaneously providing deterministic bus access. In particular, this enables both a high data bit rate such as CAN XL and the requirements for applications with strict real-time requirements.

[0015] The described subscriber station thus enables the use of CAN even for applications with strict real-time requirements. The technology of the described subscriber station is suitable for replacing FlexRay.

[0016] Another advantage is the very simple and uncomplicated configuration of the subscriber station and thus the implementation of the procedure carried out by the subscriber station in the bus system.

[0017] In addition, the described subscriber station allows the bus system to contain at least two subscriber stations that send messages to the bus according to different CAN standards. This means that, for example, in addition to two CAN-XL subscriber stations, the bus system can also contain at least one other subscriber station that sends messages to the bus according to a different / different CAN standard.

[0018] Advantageous further embodiments of the subscriber station are specified in the dependent claims.

[0019] The pause module may be configured to set the transmission delay signal to a predetermined value, according to which the transmission to the bus of a transmission message provided to the communication control device is to be delayed, only after the communication control device has transmitted N frames, where N is a natural number greater than or equal to 1.

[0020] The subscriber station may also have a message handling module for providing the transmit message to the communication controller, and a logic module for outputting the transmit message to the communication controller based on the determination of the pause module.

[0021] In one embodiment, the communication control device is designed to negotiate with the other subscriber stations in the first communication phase as to which of the subscriber stations of the bus system will receive at least temporarily exclusive, collision-free access to the bus in the subsequent second communication phase.

[0022] In one embodiment, the pause module is designed to evaluate the at least one item of status information with respect to at least one predetermined property of the predetermined frame.

[0023] The pause module may have a configuration buffer for storing a configuration parameter for the at least one predetermined property of the predetermined frame, wherein the configuration parameter is selectable for the subscriber station as required.

[0024] The at least one predetermined property may be a predetermined frame identifier of the predetermined frame. Additionally or alternatively, the at least one predetermined property is a predetermined control bit having a predetermined value. Additionally or alternatively, the at least one predetermined property is a predetermined frame format.

[0025] The subscriber station may be a master subscriber station, wherein the master subscriber station is configured to send the predetermined frame onto the bus after a predetermined period of time has elapsed.

[0026] It is conceivable that the pause module is also designed to evaluate the at least one status information in relation to at least one event on the bus.

[0027] The at least one event on the bus may include or be that the communication controller sees the bus in the idle state for one bit.

[0028] The at least one event on the bus may include or be that the communication controller has started receiving a signal corresponding to the frame from the bus.

[0029] The at least one event on the bus may include or be that the communication control device has successfully sent a signal corresponding to the frame onto the bus.

[0030] The at least one event on the bus may include or be that the communication control device has detected an error when sending a signal corresponding to the frame.

[0031] In one embodiment, the subscriber station is a master subscriber station, wherein the master subscriber station is configured to send the predetermined frame onto the bus after the pause module has detected a predetermined number of events on the bus, wherein the events include the communication controller seeing the bus in the idle state for one bit and / or the communication controller having started receiving a signal corresponding to the frame from the bus, where P is a natural number equal to or greater than 1.

[0032] The subscriber station described above may also have a signal setting block configured to change the value of the transmission delay signal after detecting the at least one event in order to delay the provision of a transmission message to the communication control device.

[0033] The subscriber station described above may also have a transmitting / receiving device which is connected to the bus and is designed to generate a digital received signal from the at least one signal received from the bus, wherein the communication control device is designed to sample and evaluate the received signal generated by the transmitting / receiving device according to the predetermined frame.

[0034] At least one of the preceding subscriber stations may be part of a bus system which also comprises a bus and at least one previously described master subscriber station, wherein the at least one subscriber station and the at least one master subscriber station are connected to one another via the bus in such a way that the subscriber stations can communicate with one another serially.

[0035] The above-mentioned object is also achieved by a method for deterministic communication in a serial bus system according to claim 18. The method is carried out with a subscriber station which has a communication control device and a pause module, wherein the communication control device is designed to control communication of the subscriber station with at least one other subscriber station of the bus system by generating a message based on a frame and by sending the message to a bus of the bus system and by evaluating at least one signal received from a bus of the bus system based on the frame, in which frame the bit time in a first communication phase can differ from a bit time in a second communication phase, and wherein the method comprises the steps of evaluating, with the pause module,at least one piece of status information output by the communication control device regarding whether or not a predetermined frame has been received from the bus, and generating, with the pause module based on a result of its evaluation, a transmission delay signal to delay or not delay the provision of a transmission message to the communication control device, wherein the transmission message is to be sent by the communication control device as a message on the bus.

[0036] The method offers the same advantages as previously mentioned with regard to the subscriber station.

[0037] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention. Drawings

[0038] The invention is described in more detail below with reference to the accompanying drawings and exemplary embodiments. They show: Fig. 1 shows a simplified block diagram of a bus system according to a first embodiment; Fig. 2 is a diagram illustrating the structure of a message that can be sent by a subscriber station of the bus system according to the first embodiment, which does not have a master function in the bus system; Fig. 3 is a diagram illustrating the structure of a message that can be sent by a master subscriber station of the bus system according to the first embodiment; Fig. 4 is a schematic block diagram of a subscriber station of the bus system according to the first embodiment, which does not have a master function in the bus system; Fig. 5 a time course of a digital transmission signal during operation of the bus system at the subscriber station of Fig. 4, which is connected to the same bus of the bus system with at least one second subscriber station; Fig. 6 a time course of bus signals CAN_H and CAN_L at the subscriber station of Fig. 4; Fig. 7 shows a time course of a differential voltage VDIFF of the bus signals CAN_H and CAN_L at the subscriber station of Fig. 4; Fig. 8 shows a time course of a digital reception signal that the subscriber station receives from Fig. 4 generated from a signal received from the bus; Fig. 9 is a diagram of states on a bus of the bus system over time, which can occur during operation of the bus system according to the first embodiment; Fig. 10 a time course of a signal for enabling or not enabling the transmission of the subscriber station from Fig. 4 to the bus of the bus system of Fig. 1; and Fig. 11 is a diagram illustrating the structure of a message that can be sent by a master subscriber station of the bus system according to a second embodiment.

[0039] In the figures, identical or functionally identical elements are provided with the same reference numerals unless otherwise stated. Description of the embodiments

[0040] Fig. 1 shows, as an example, a bus system 1, which is configured, in particular, fundamentally for a CAN bus system, a CAN FD bus system, a CAN XL bus system, and / or modifications thereof, as described below. The bus system 1 can be used in a vehicle, in particular a motor vehicle, an aircraft, etc., or in a hospital, etc.

[0041] In Fig. 1, the bus system 1 has a plurality of subscriber stations 10, 20, 30, each connected to a bus 40 with a first bus wire 41 and a second bus wire 42. The bus wires 41, 42 can also be called CAN_H and CAN_L and are used for electrical signal transmission after coupling in the dominant levels or generating recessive levels or other levels for a signal in the transmit state.

[0042] Via the bus 40, messages 45, 46 are transmitted based on a frame according to Fig. 2 and can be transmitted serially in the form of signals between the individual subscriber stations 10, 20, 30. If a fault occurs during communication on bus 40, as indicated by the jagged black block arrow in Fig. As shown in Figure 1, one of the subscriber stations 10, 20, 30 can optionally send an error frame 47 with an error flag and an error delimiter. In particular, the interference can cause the subscriber stations 10 to detect an error when sending a message 45, 46, which corresponds to an event E4. The interference is in Fig. 1 as a jagged arrow. The participant stations 10, 20, 30 of Fig. 1 are, for example, control units, sensors, display devices, etc. of a motor vehicle or other technical system.

[0043] The subscriber station 30 is also referred to as the master in the following, since the subscriber station 30 begins sending a predetermined message 48 according to a predetermined frame 450_B of Fig. 3 via the bus 40 when the subscriber stations 10, 20 send a message 45, 46 based on a frame of Fig. 2 on the bus 40. The predetermined frame 450_B is in Fig. 3 and Fig. 9 and described in more detail below.

[0044] Accordingly, in the present embodiment, the subscriber stations 10, 20 do not have a master function. The subscriber stations 10, 20 are therefore also referred to as non-master subscriber stations or slave subscriber stations.

[0045] As in Fig. 1, the subscriber station 10 has a communication control device 11, a transmitting / receiving device 12 and a transmitting / waiting device 15. The subscriber station 20 has a communication control device 21, a transmitting / receiving device 22 and a transmitting / waiting device 25. The subscriber station 30 has a communication control device 31, a transmitting / receiving device 32 and a transmitting / waiting device 35. The transmitting / receiving devices 12, 22, 32 of the subscriber stations 10, 20, 30 are each directly connected to the bus 40, even if this is not shown in Fig. 1 is not illustrated.

[0046] The communication control devices 11, 21, 31 each serve to control communication between the respective subscriber station 10, 20, 30 via the bus 40 and at least one other subscriber station of the subscriber stations 10, 20, 30 connected to the bus 40. For this purpose, the communication control devices 11, 31 create and / or read first messages 45, which are, for example, CAN FD messages 45. The CAN FD messages 45 are structured based on a CAN FD format specified in ISO11898-1:2015.

[0047] The communication control devices 11, 31 can also be configured to provide a CAN FD message 45 or a CAN XL message 46 for the associated transmitting / receiving device 12, 32 or to receive one from the latter, as needed. The communication control devices 11, 31 thus create and read a first message 45 or a second message 46, wherein the first and second messages 45, 46 differ in their data transmission standard, namely CAN FD or CAN XL in this case. The CAN XL messages 46 are structured based on a CAN XL format defined in CiA610-1 or ISO11898-1.

[0048] The communication control device 21 can be designed like a conventional CAN controller according to ISO 11898-1:2015, i.e., like a CAN FD-tolerant Classical CAN controller or a CAN FD controller. The communication control device 21 creates and reads initial messages 45, for example, CAN FD messages 45. The CAN FD messages 45 can contain from 0 to 64 data bytes, which are also transmitted at a significantly faster data rate than a Classical CAN message. In particular, the communication control device 21 is designed like a conventional CAN FD controller.

[0049] The transmitting / receiving devices 12, 32 can be designed to provide messages 45 according to the CAN FD format or messages 46 according to the CAN XL format for the associated communication control device 11, 31 or to receive them from the latter, as required.

[0050] The transmitting / receiving device 22 can be designed as a conventional CAN transceiver according to ISO 11898-1:2015 or CAN FD transceiver.

[0051] In addition, the transmission waiting devices 15, 25, 35 are present, which are described in more detail below.

[0052] Fig. 2 shows the basic structure of a frame 450 for the message 45, as provided by the communication control device 11 for the transmitting / receiving device 12 for sending onto the bus 40.

[0053] According to Fig. 2, frame 450 for CAN communication on bus 40 is divided into different communication phases 451, 452, namely an arbitration phase 451 (first communication phase) and a data phase 452 (second communication phase). After a start bit SOF, frame 450 has an arbitration field 453, a control field 454, a data field 455, a checksum field 456, and a frame end field 457. A frame is used for message 46 which has the same basic structure as for frame 450 in Fig. 2 shown.

[0054] In the arbitration phase 451, using an identifier (ID) with, for example, bits ID28 to ID18 in the arbitration field 453, the subscriber stations 10, 20, 30 negotiate bit by bit to determine which subscriber station 10, 20, 30 wishes to send the message 45, 46 with the highest priority and will therefore receive exclusive access to the bus 40 of the bus system 1 for the next transmission time in the subsequent data phase 452. In the arbitration phase 451, a physical layer is used with the bus states dominant and recessive. The physical layer corresponds to the physical layer or layer 1 of the well-known OSI model (Open Systems Interconnection Model).

[0055] A sender of message 45, for example, subscriber station 10, begins sending bits of control field 454 and bits of data phase 452 to bus 40 only if subscriber station 10, as the sender, has won the arbitration and subscriber station 10, as the sender, thus has exclusive access to bus 40 of bus system 1 for sending. The same applies to subscriber stations 20, 30 if they wish to send a message 45 or 46 to bus 40.

[0056] In the data phase 452, in addition to a part of the control field 454, the payload data of the frame 450 or the message 45 or the message 46 from the data field 455 and the checksum field 456 are sent.

[0057] The checksum field 456 may contain a checksum of the data from the data phase 452. At the end of the data phase 452, the system switches back to the arbitration phase 451.

[0058] An ACK bit slot is provided in the frame end field 457, in which subscriber stations that are currently only receivers of frame 450 but not senders of the frame can confirm or not confirm the correct receipt of frame 450 from bus 40. An ACK-Del bit, also called an ACK delimiter, is also provided. A bit sequence is provided in the frame end field 457 that marks the end of frame 450. The bit sequence at the end of the frame end field 457 thus serves to identify the end of frame 450. The bit sequence cannot occur within frame 450. This allows subscriber stations 10, 20, and 30 to reliably detect the end of frame 450.

[0059] After the frame end field 457 there follows an inter-frame space (IFS - Inter Frame Space), which is Fig. 2 is not shown. This interframe space (IFS) is designed for CAN FD according to ISO 11898-1:2015. The interframe space (IFS) has a minimum of 3 bits.

[0060] Furthermore, the fields and bits mentioned are known from ISO11898-1:2015 and CiA610-1 respectively and are therefore not described in detail here.

[0061] Thus, in the arbitration phase 451, the first communication phase, subscriber stations 10 and 30 partially use a format known from CAN / CAN FD according to ISO 11898-1:2015. However, compared to CAN in the data phase 452, the second communication phase, CAN FD and CAN XL allow an increase in the net data transmission rate, up to 20 megabits per second for CAN XL. Furthermore, CAN XL allows an increase in the size of the payload data per frame to up to 2048 bytes.

[0062] An important point during phase 451 at the beginning of the frame is that the well-known CSMA / CR method is used, which allows simultaneous access of the subscriber stations 10, 20, 30 to the bus 40 without destroying the higher-priority message 45, 46. This allows additional bus subscriber stations 10, 20, 30 to be added to the bus system 1 relatively easily, which is very advantageous.

[0063] The CSMA / CR method requires the existence of so-called recessive states on bus 40, which can be overwritten by other subscriber stations 10, 20, or 30 with dominant states on bus 40. In the recessive state, high-impedance conditions prevail at the individual subscriber stations 10, 20, or 30, which, in combination with the parasitics of the bus circuitry, results in longer time constants. This limits the maximum bit rate of today's CAN FD physical layer to approximately 2 megabits per second in real-world vehicle use. With the new CAN SIC physical layer, 5 megabits per second and up to 8 megabits per second are also possible.

[0064] Fig. Figure 3 shows a predetermined frame 450_B, also called a BEACON frame. The subscriber station 30 (master) of Fig. 1 regularly sends a message 48 on the bus 40 based on or according to the predetermined frame 450_B. The predetermined frame 450_B is a normal CAN frame that is Fig. 2 previously described. However, the frame 450_B of Fig. 3 at least one special or predetermined property 1521A.

[0065] The at least one special or predetermined property 1521A comprises, for example, a field with a predetermined value. Thus, the predetermined frame 450_B (BEACON frame) can be a normal frame, in particular a CAN FD frame, with payload data. Furthermore, the at least one predetermined property 1521A is, in particular, that the predetermined frame 450_B has a special or predetermined frame identifier (ID) and / or that the predetermined frame 450_B has an RRS bit with the value 1 and / or that the predetermined frame 450_B is a CAN FD frame.

[0066] The master subscriber station, which in the described example is subscriber station 30, has two basic options for transmitting the predetermined frame 450_B (BEACON frame). According to a first option, the master subscriber station transmits the predetermined frame 450_B in a time-controlled manner, for example, every 10 milliseconds or after the expiration of any other suitable time period. According to a second option, the master subscriber station transmits the predetermined frame 450_B in an event-controlled manner. For example, when the master subscriber station has seen a predetermined number P of events after transmitting the predetermined frame 450_B. P is a natural number greater than or equal to 1. Events can be, for example, as follows.

[0067] Event E1: Idle bit i seen; this means that the subscriber station 30 (master) sees the bus 40 in the "idle" state, or standby or idle state, for one bit i. The "idle" state occurs when the minimum interframe interval (3 bits) has elapsed and no subscriber station sends a frame on the CAN bus.

[0068] Event E2: Frame reception started; that is, the subscriber station 30 (master) has started receiving a frame 450 from the bus 40.

[0069] Fig. Figure 4 shows the basic structure of the subscriber station 10 with the communication control device 11, the transmitting / receiving device 12, and the separately arranged transmit / wait device 15. The subscriber station 20 is identically constructed with respect to the transmit / wait device 15. The subscriber station 30 can be constructed in a similar manner as in Fig. 4. In the example of Fig. 1, however, the transmission waiting device 35 is integrated into the communication control device 31. Therefore, the subscriber station 30 is not described separately.

[0070] According to Fig. 4, the subscriber station 10 has, in addition to the communication control device 11, the transmit / receive device 12, and the transmit / wait device 15, a microcontroller 13, to which the communication control device 11 is assigned, and a system ASIC 16 (ASIC = Application-Specific Integrated Circuit), which can alternatively be a system base chip (SBC) on which several functions necessary for an electronic module of the subscriber station 10 are combined. In addition to the transmit / receive device 12, the system ASIC 16 contains a power supply device 17, which supplies the transmit / receive device 12 with electrical power. The power supply device 17 typically supplies a CAN_Supply voltage of 5 V. However, depending on requirements, the power supply device 17 can supply a different voltage with a different value.Additionally or alternatively, the energy supply device 17 can be designed as a power source.

[0071] The transmission waiting device 15 can be arranged in a separate microcontroller (not shown), as in Fig. 3. Alternatively, the transmission waiting device 15 can be arranged in the microcontroller 13.

[0072] The transmit wait device 15 has a message handling module 151, a pause module 152 and a logic module 153. The modules 151, 152, 153 create and / or process digital signals TX_D, TX_R, TX_E and TX_S.

[0073] The pause module 152 may be arranged in the transmission waiting device 15, as shown in Fig. 3. Alternatively, the pause module 152 is assigned to the device 11, in particular arranged in the device 11. Alternatively, the pause module 152 can be arranged separately from the transmission waiting device 15 and separately from the microcontroller 13 and the device 11.

[0074] The message handling module 151 has a send message buffer 1511 for storing at least one send message 1511A, a receive message buffer 1512 for storing at least one receive message 1512A, and an evaluation block 1513. The pause module 152 has a configuration buffer 1521, a (release) signal setting block 1522, and an evaluation block 1523.

[0075] In the pause module 152, the predetermined frame property 1521A is stored in the configuration buffer 1521 as a configuration parameter and, optionally, at least one configuration parameter 1521B for a type of event. The signal setting block 1522 serves to set the TX_E signal such that the transmission of the transmission message 1511A to the communication control device 11 is no longer delayed.

[0076] The logic module 153 is designed for a logical combination of signals. In the example of Fig. 4, the logic module 153 is an AND module. However, the logic module 153 is not limited to this, but can have at least one other module so that the logic module 153 fulfills its function described below.

[0077] The predetermined frame property 1521A configures the transmission wait device 15 or the pause module 152. For this purpose, the predetermined frame property 1521A can be set as needed, particularly during commissioning of the subscriber station 10, or stored in the configuration buffer 1521. The predetermined frame property 1521A determines what kind of predetermined frame 450_B the subscriber station 10 must receive from the bus 40 so that the subscriber station 10 may forward a transmission message 1511A provided in the transmission message buffer 1511 to the communication control device 11, so that the subscriber station 10 creates a corresponding TXD signal and forwards it to the transceiver device 12 for transmission on the bus 40. The configuration parameter 1521B for the at least one type of event is described in more detail below.

[0078] The transmission waiting device 15 is described below with reference to Fig. 9 and Fig. 10 described in more detail.

[0079] According to Fig. 4, the system ASIC 16 has, in particular, an application 161, which can be embodied as a computer program (app) or software. Such an application is a technical application 161. The application 161 is, for example, any application in a vehicle. In particular, the application is a controller for an air conditioning system and / or a windshield washer system and / or a driver assistance system, etc. For example, the windshield washer system controls the movement of at least one windshield wiper (actuator) using data from a rain sensor and / or wind sensor and / or speed sensor and / or light sensor, and / or a warning light (actuator) can be switched on or off. However, the application 161 is not limited to one of the systems mentioned or parts thereof.

[0080] The transmitting / receiving device 12 also has a transmitting module 121 and a receiving module 122. Although the following always refers to the transmitting / receiving device 12, it is alternatively possible to provide the receiving module 122 in a separate device external to the transmitting module 121. The transmitting module 121 and the receiving module 122 can be constructed as in a conventional transmitting / receiving device 22. The transmitting module 121 can, in particular, have at least one operational amplifier and / or one transistor. The receiving module 122 can, in particular, have at least one operational amplifier and / or one transistor.

[0081] The transceiver device 12 is connected to the bus 40, more precisely to its first bus wire 41 for CAN_H and its second bus wire 42 for CAN_L. The voltage supply for the power supply device 17 for supplying the first and second bus wires 41, 42 with electrical energy, in particular with the CAN supply voltage, is provided via at least one connection (not shown in the figures). The connection to ground or CAN_GND is realized via a connection (not shown). The first and second bus wires 41, 42 are terminated with a terminating resistor (not shown).

[0082] The first and second bus wires 41, 42 are connected in the transmitting / receiving device 12 not only to the transmitting module 121, but also to the receiving module 122, even if the connection in Fig. 4 is not shown for simplicity. The transmitting module 121 is also referred to as a transmitter. The receiving module 122 is also referred to as a receiver.

[0083] During operation of the bus system 1, the transmitter module 121 can Fig. 4 serially convert a transmission signal TXD of the communication control device 11 into corresponding signals CAN_H, CAN_L for CAN or CAN FD and into signals CAN_XL_H, CAN_XL_L for CAN XL for the bus wires 41, 42. The transmission module 121 transmits these signals to the bus wires 41, 42 of the bus 40. The digital transmission signal TXD is based on a frame 450 according to Fig. 2, as mentioned previously.

[0084] Fig. Figure 5 shows an example of a transmission signal TXD over time t. Fig. 6 shows the signal TXD from the transmission Fig. 5 resulting signals CAN_H, CAN_L on bus 40.

[0085] According to the example of Fig. 6, the signals CAN_H and CAN_L have the dominant and recessive bus levels 402, 401, as known from CAN, at least in the arbitration phase 451. On the bus 40, a difference signal VDIFF = CAN_H - CAN_L is formed, which in Fig. 7 for the arbitration phase 451. The individual bits of the VDIFF signal or CAN_H, CAN_L have a bit time t_bt1 in the arbitration phase 451. In the data phase 452, the bits of the CAN_H and CAN_L signals for CAN FD and CAN XL can be sent faster, i.e., with a shorter bit time t_bt2, than in the arbitration phase 451. Thus, the CAN_H and CAN_L signals for CAN FD and CAN XL differ from the conventional CAN_H and CAN_L signals in the data phase 452 at least in their faster bit rate.

[0086] The sequence of states 401, 402 for the signals CAN_H, CAN_L in Fig. 6 and the resulting voltage curve VDIFF of Fig. 7 only serves to illustrate the function of the subscriber station 10. The sequence of data states for the bus states 401, 402 can be selected as required.

[0087] The receiver module 122 of Fig. 4 forms a digital receive signal RXD ( Fig. 8) and forwards this to the communication control device 11, as shown in Fig. 4 shown.

[0088] In an operating mode B_LB (Idle), the communication control device 11 has detected the idle or standby state of the CAN bus 40. This means that the communication control device is waiting to receive a message 45, 46. In this state, no communication takes place on the bus 40. In other words, at the connection of the communication control device 11 of Fig. 4 for the receive signal RXD from Fig. 8 no signal is received or the value is logical 1, since the recessive level on bus 40 corresponds to a bit value = 1 or a logical 1 in the receive signal RXD.

[0089] The functionality of the transmission waiting device 15, which differs from the current communication standards for Classical CAN, CAN FD and CAN XL, is also explained below using Fig. 9 and Fig. 10. The modules and / or blocks of the device 15 can be implemented in hardware and / or software.

[0090] At the transmission waiting facility 15 of Fig. 4, the message handling module 151, in particular its evaluation block 1513, evaluates whether a send message 1511A is ready for transmission in the send message buffer 1511. Optionally, the evaluation block 1513 can evaluate whether a receive message 1512A is stored in the receive message buffer 1512. If a send message 1511A is ready for transmission, the message handling module 151, in particular its evaluation block 1513, signals this readiness by setting the TX_R signal accordingly. In particular, the evaluation block 1513 sets the TX_R signal to logic 1. At the same time, the message handling module 151, in particular its evaluation block 1513, provides the communication control device 11 with the data or the send message 1511A as the TX_D signal. The communication control device 11 sends the data orthe transmission message 1511A according to a frame 450 as signal TXD on the CAN bus 40 if the signal TX_S is set accordingly and the CAN bus 40 is not occupied by another message.

[0091] The following procedure is used to set the TX_S signal. The pause module 152 receives at least one piece of status information ST_A from the communication control device 11. The at least one piece of status information ST_A indicates a status or condition Z_40 on the bus 40. The status information(s) ST_A contain(s) at least one piece of information about a frame 450, 450_B received from the bus 40, to which the pause module 152 responds. For this purpose, the pause module 152 evaluates the at least one piece of status information ST_A using the configuration buffer 1521, in which the predetermined frame property 1521A is stored.

[0092] The pause module 152, in particular its evaluation block 1523, creates a digital signal TX_E as the result of its evaluation. The pause module 152, in particular its evaluation block 1523, outputs the signal TX_E to the logic module 153. The signal TX_E is also referred to below as the transmit delay signal TX_E. Alternatively, the signal TX_E can be referred to as the transmit enable signal TX_E.

[0093] For example, TX_E = 0 means that the transmission of a frame 450 or the signal T_D corresponding to the transmission message 1511A may not be started. In this example, a logical value of 1 for the signal TX_E or TX_E = 1 means that the transmission of a frame 450 may be started based on the signal T_D corresponding to the transmission message 1511A. If the transmission of a frame 450 based on the signal T_D corresponding to the transmission message 1511A may not be started, the pause module 152 delays the provision of the transmission message 1511A for the communication control device 11 to the transceiver 12. If the transmission of a frame 450 or the signal T_D corresponding to the transmission message 1511A may be started, the pause module 152 does not delay the provision of the transmission message 1511A for the communication control device 11 in a frame 450 to the transceiver 12.In general, the pause module 152 may enable or disable the provision and / or transmission of the transmit message 1511A to the communication control device 11 and / or the provision to the transceiver device 12 for transmission on the bus 40.

[0094] The logic module 153 combines the signal TX_E with the digital signal TX_R and outputs a digital signal TX_S.

[0095] Only if the transmit wait device 15 has determined that the transmit message 1511A may be sent on the bus 40 is a corresponding signal TX_S output to the communication control device 11. In the aforementioned example for the signal TX_E and the logic module 153, the transmit wait device 15, in particular its logic module 153, outputs the signal TX_S=1 to the communication control device 11 if the transmission of a frame 450 or the signal T_D corresponding to the transmit message 1511A may begin.

[0096] The pause module 152 has the signal setting block 1522, with which the signal TX_E is set according to at least one predetermined property 1521A of the predetermined frame 450_B, so that the transmission of the transmission message 1511A by the communication control device 11 in a frame 450 to the transceiver 12 is no longer delayed. To determine whether the frame 450, 450_B received from the bus 40 has the at least one predetermined property 1521A, the pause module 152, in particular its evaluation block 1523, evaluates the status information ST_A that the communication control device 11 transmits.

[0097] The pause module 152, more specifically its signal setting block 1522, sets the signal TX_E when the evaluation block 1523 evaluates or detects in the status information ST_A that a predetermined frame 450_B is received. A predetermined frame 450_B is a frame that has the at least one predetermined property 1521A, as previously described.

[0098] If one of the following events E3 to E5 occurs, the pause module 152, more precisely its signal setting block 1522, resets the signal TX_E, in particular to 0, in order to delay the forwarding of the transmission message 1511A to the device 11 or, in a frame 450, to the transmitting / receiving device 12. Whether all three different events E3 to E5 or only a subset, in particular at least one of the events E3 to E5, are / will be evaluated, can be implementation-specific or can be configurable for the user by means of the optional at least one type or parameter 1521B.

[0099] To count events E1 to E2 in the status information ST_A, the signal setting block 1522 of a master subscriber station can have at least one counter. The at least one counter serves to count events E1 and E2 and thereby determines a counter value that can be reset by resetting to an initial value, in particular 0. Events E3 to E5, preferably only E3 and E4 when transmitting the predetermined frame 450_B, serve to reset the counter. After the reset, the counting of events E1 and E2 begins again. Whether the counter is reset or set, and whether the counting is an increment or decrement, is irrelevant for the described function.

[0100] Event E3: Subscriber station 10 has successfully sent a frame 450 or a transmission message 1511A to the other subscriber stations 20, 30 of bus system 1. This means that the transmitting subscriber station 10 has received an acknowledgment of receipt in the designated ACK area (at least one bit) in frame 450 from at least one receiving station. Thus, an entire frame 450 was successfully sent.

[0101] Event E4: Subscriber station 10 has detected an error during transmission and aborts the transmission of the frame, or subscriber station 10 sees an ACK error, which means that subscriber station 10 has not received an "error-free" acknowledgment of receipt in the designated ACK area (at least one bit) in frame 450 from the receiving stations.

[0102] Event E5: Subscriber station 10 has started sending a frame 450 based on a send message 1511A on bus 40.

[0103] In particular, only events E3 and E4 are used. This combination allows subscriber station 10 to retry transmitting a frame 450 an infinite number of times after subscriber station 10 has lost arbitration. This is desirable and thus advantageous because subscriber stations 10, 20, and 30 on bus 40 do not have a fixed transmission order, and thus arbitration occurs regularly.

[0104] Fig. 9 and Fig. 10 illustrates the previously described functionality of subscriber station 10 in bus system 1 over time t for a specific example in more detail. The following definitions apply to this example: A) The subscriber station 30 is the master subscriber station and sends predetermined frames 450_B, as in Fig. 3 and described previously. Subscriber station 30 also functions as a slave subscriber station. After receiving the predetermined frame 450_B, each of the subscriber stations 10, 20, and 30 may transmit a frame 450. This means that the bandwidth on bus 40 is divided equally among the subscriber stations 10, 20, and 30. Subscriber station 30 transmits the predetermined frame 450_B when it has seen a total of three events of type E1 and / or E2. B) In all 3 participant stations 10, 20, 30 of Fig. 1 the signal TX_E is reset when event E3 or event E4 occurs. C) After the start, the subscriber station 10 wants to send two frames or send messages 1511A on the bus 40. D) The subscriber stations 20, 30 transmit only sporadically.

[0105] Fig. Figure 9 visualizes the state or status Z_40 on the bus 40 over time t for the specific example. The pause module 152 forms the signal TX_E from the status Z_40 of Fig. 10, as described above. For clarity, Fig. 9 only shows the view of subscriber station 10 and is described in more detail below. The view of subscriber stations 20, 30 and the signal TX_E generated by the subscriber stations 20, 30 are shown accordingly.

[0106] In the specific example of Fig. 9, the participant stations 10, 20, 30 ( Fig. 1) are switched on and are in Fig. 9 all operational.

[0107] Now all participant stations 10, 20, 30 ( Fig. 1) to wait for the reception of the predetermined frame 450_B in order to be able to set the TX_E signal, as previously described.

[0108] First, the subscriber station 10 receives two idle bits i (twice event E1) from the bus 40. At the beginning of the next frame, which is recognized by the start bit SOF, as with respect to Fig. 2, the subscriber station 10 switches to receive (event E2). The master subscriber station 30, having detected event E1 three times, transmits the predetermined frame 450_B to the bus 40. In Fig. For reasons of space, only two events E1 are shown in Figure 9.

[0109] After receiving the predetermined frame 450_B, the subscriber station 10 sets the signal TX_E to 1, as shown in Fig. 10. Since the signal TX_E = 1, the subscriber station 10 starts transmitting (event E5).

[0110] However, subscriber station 10 loses the arbitration twice, as follows. First, in arbitration A123, all subscriber stations 10, 20, and 30 participate in the arbitration, whereby subscriber station 30 is allowed to send its frame 450 or transmit message 1511A, as with A123, TX3 in Fig. 9. Subsequently, at the arbitration A12, the subscriber stations 10, 20 participate in the arbitration, whereby the subscriber station 20 may send its frame 450 or send message 1511A, as with A12, TX2 in Fig. 9. On the third transmission attempt, the subscriber station 10 can successfully transmit its frame, as shown with A1, TX1 in Fig. 9 shown.

[0111] At time T1, i.e. after the successful transmission (event E3), the subscriber station 10 sets the signal TX_E back to 0, as in Fig. 10 shown.

[0112] At the beginning of the next frame, which is recognized by the start bit SOF, as in relation to Fig. 2, the subscriber station 10 switches to receive (event E2).

[0113] Subsequently, after receiving the predetermined frame 450_B, the subscriber station 10 sets the signal TX_E to 1, as shown in Fig. 10. Since the signal TX_E = 1, the subscriber station 10 starts transmitting (event E5). Arbitration does not occur. Therefore, the subscriber station 10 can successfully transmit its second frame 450 or transmit message 1511 A, as shown with A1, TX1 in Fig. 9 shown.

[0114] At time T2, i.e. after the successful transmission (event E3), the subscriber station 10 sets the signal TX_E back to 0, as in Fig. 10 shown.

[0115] Subsequently, the subscriber station 10 receives two idle bits i from the bus 40 (twice event E1).

[0116] At the beginning of the next frame, which is recognized by the start bit SOF, as in relation to Fig. 2, the subscriber station 10 switches to receive (event E2).

[0117] In addition, after receiving the next predetermined frame 450_B, the subscriber station 10 sets the signal TX_E back to 1, as shown in Fig. 10 illustrates.

[0118] The design of subscriber station 10 thus offers a very simple and straightforward configuration of subscriber station 10 and implementation of the process it executes in bus system 1. The same applies to the other subscriber stations 20, 30.

[0119] Fig. 11 shows a predetermined frame 450_B1 that can be generated by the master subscriber station according to a second embodiment.

[0120] The predetermined frame 450_B1 contains a cycle counter 4501, which is in particular a count value. The master subscriber station is configured to cyclically increment the cycle counter 4501 in successive predetermined frames 450_B1.

[0121] The subscriber stations 10, 20, 30 can then be configured to send different numbers of frames 450 to the bus 40 in different cycles, i.e. depending on the count value of the cycle counter.

[0122] In this way, the relationship between determinism and arbitration or priority-based transmit access in the bus system 1 can also be configured.

[0123] According to a third embodiment, the transmit wait device 15 of at least one subscriber station 10 of the bus system 1 is configured to transmit up to N frames consecutively before the device 15 sets its signal TX_E = 0. N is a configurable parameter. N is a natural number greater than or equal to 1.

[0124] Accordingly, a subscriber station 10, 20, 30 can send up to N frames 450 consecutively after receiving the predetermined frame 450_B. A reasonable value range for N is 1 to 10, because this also increases or increases the chance for other subscriber stations in bus system 1 to send frame 450.

[0125] In this way, one of the subscriber stations 10, 20, or 30 can be allowed to send message bursts. This is particularly advantageous when a subscriber station sends predominantly short messages compared to the other subscriber stations. This avoids unfairness in the distribution of the available communication bandwidth in bus system 1.

[0126] According to a fourth embodiment, not only one master subscriber station is present in the bus system 1.

[0127] Thus, for example, there may be two or more master stations. The second or third, etc., master station may act as a backup master station. Specifically, station 20 is the backup master station, and station 30 is the master station.

[0128] The backup master subscriber station is configured to detect whether the predetermined frame 450_B is received at least once from the bus 40 within a predetermined time T_C. The predetermined time T_C may also be referred to as a timeout time. The predetermined time T_C may be stored as a configuration parameter 1521B in the configuration buffer 1521.

[0129] If the backup master subscriber station does not receive the predetermined frame 450_B at least once from bus 40 within the predetermined time T_C, the backup master subscriber station will transmit the predetermined frame 450_B instead of the master subscriber station from now on until the master subscriber station is operational again. In this case, the backup master subscriber station will receive the predetermined frame 450_B again from bus 40 from the master subscriber station.

[0130] In this way, the reliability of communication in the bus system 1 is increased.

[0131] All previously described embodiments of the subscriber stations 10, 20, 30, of the bus system 1, and of the method implemented therein can be used individually or in any possible combination. In particular, all features of the previously described embodiments and / or modifications thereof can be combined as desired. Additionally or alternatively, the following modifications are particularly conceivable.

[0132] Even though the invention has been described above using the example of the CAN bus system, the invention can be used in any communication network and / or communication method in which two different communication phases are used in which the bus states generated for the different communication phases differ.

[0133] In particular, the bus system 1 according to the exemplary embodiments can be a communications network in which data can be transmitted serially at two different bit rates. It is advantageous, but not a mandatory requirement, that the bus system 1 ensures exclusive, collision-free access of a subscriber station 10, 20, 30 to a common channel, at least for certain time periods.

[0134] The number and arrangement of the subscriber stations 10, 20, 30 in the bus system 1 of the exemplary embodiments is arbitrary. In particular, the subscriber station 20 can be omitted from the bus system 1. It is possible for one or more of the subscriber stations 10 or 30 to be present in the bus system 1. It is conceivable for all subscriber stations in the bus system 1 to be configured identically, i.e., for only subscriber stations 10 or only subscriber stations 30 to be present. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] ISO11898-1:2015 [0003, 0060, 0061]

Claims

[1] Subscriber station (10; 20; 30) for deterministic communication in a serial bus system (1), with a communication control device (11; 21; 31) for controlling communication between the subscriber station (10; 20; 30) and at least one other subscriber station (20; 30; 10) of the bus system (1) by generating a message (45; 46) based on a frame (450) and by sending the message (45; 46) to a bus (40) of the bus system (1) and by evaluating at least one signal (VDIFF; RXD) received from a bus (40) of the bus system (1) based on the frame (450), in which frame (450) the bit time (t_bt1) in a first communication phase (451) can differ from a bit time (t_bt2) in a second communication phase (452), and a pause module (152) for evaluating at least one item of status information (ST_A) output by the communication control device (11; 21; 31) with regard to whether or not a predetermined frame (450_B) has been received from the bus (40), wherein the pause module (152) is configured to generate and output a transmission delay signal (TX_E) on the basis of a result of its evaluation in order to delay or not delay the provision of a transmission message (1511A) to the communication control device (11; 21; 31), wherein the transmission message (1511A) is to be sent by the communication control device (11; 21; 31) as a message (45; 46) onto the bus (40). [2] Subscriber station (10; 20; 30) according to claim 1, wherein the pause module (152) is configured to set the transmission delay signal (TX_E) to a predetermined value, according to which the transmission to the bus (40) of a transmission message (1511A) provided for the communication control device (11; 21; 31) is to be delayed after the communication control device (11; 21; 31) has transmitted N frames (450), and where N is a natural number greater than or equal to 1. [3] Subscriber station (10; 20; 30) according to claim 1 or 2, further comprising a message handling module (151) for providing the transmission message (1511A) for the communication control device (11; 21; 31), and a logic module (153) for outputting the transmission message (1511A) to the communication control device (11; 21; 31) based on the determination of the pause module (152). [4] Subscriber station (10; 20; 30) according to one of the preceding claims, wherein the communication control device (11; 21; 31) is designed to negotiate with the other subscriber stations (10; 20; 30) in the first communication phase (451) which of the subscriber stations (10, 20, 30) of the bus system (1) receives at least temporarily exclusive, collision-free access to the bus (40) in the subsequent second communication phase (452). [5] Subscriber station (10; 20; 30) according to one of the preceding claims, wherein the pause module (152) is designed to evaluate the at least one item of status information (ST_A) with respect to at least one predetermined property (1521A) of the predetermined frame (450_B). [6] Subscriber station (10; 20; 30) according to claim 5, wherein the pause module (152) comprises a configuration buffer (1521) for storing a configuration parameter for the at least one predetermined property (1521A) of the predetermined frame (450_B), and wherein the configuration parameter is selectable for the subscriber station (10; 20; 30) as required. [7] Subscriber station (10; 20; 30) according to claim 5 or 6, wherein the at least one predetermined property (1521A) is a predetermined frame identifier of the predetermined frame (450_B) and / or a predetermined control bit with a predetermined value and / or a predetermined frame format. [8] Subscriber station (30) according to one of the preceding claims, wherein the subscriber station (30) is a master subscriber station, and wherein the master subscriber station (30) is configured to send the predetermined frame (450_B) to the bus (40) after a predetermined period of time has elapsed. [9] Subscriber station (30) according to one of the preceding claims, wherein the pause module (152) is also designed to evaluate the at least one status information item (ST_A) with respect to at least one event (E1; E2; E3; E4; E5) on the bus (40). [10] Subscriber station (10; 20; 30) according to claim 9, wherein the at least one event (E1) on the bus (40) comprises the communication control device (11; 21; 31) seeing the bus (40) in the idle state for one bit (i). [11] Subscriber station (10; 20; 30) according to claim 9 or 10, wherein the at least one event (E2) on the bus (40) comprises that the communication control device (11; 21; 31) has started receiving a signal (VDIFF; RXD) corresponding to the frame (450) from the bus (40). [12] Subscriber station (10; 20; 30) according to one of claims 9 to 11, wherein the at least one event (E3) on the bus (40) comprises that the communication control device (11; 21; 31) has successfully sent a signal (TXD; CAN_H, CAN_L) corresponding to the frame (450) onto the bus (40). [13] Subscriber station (10; 20; 30) according to one of claims 9 to 12, wherein the at least one event (E4) on the bus (40) comprises that the communication control device (11; 21; 31) has detected an error when transmitting a signal (TXD; CAN_H, CAN_L) corresponding to the frame (450). [14] Subscriber station (30) according to one of claims 9 to 13, wherein the subscriber station (30) is a master subscriber station, and wherein the master subscriber station (30) is configured to send the predetermined frame (450_B) onto the bus (40) after the pause module (152) has detected a predetermined number (P) of events (E1; E2) according to one of claims 11 or 12 on the bus (40), where P is a natural number equal to or greater than 1. [15] Subscriber station (10; 20; 30) according to one of the preceding claims, further comprising a signal setting block (1522) which is designed to change the value of the transmission delay signal (TX_E) after detecting the at least one event (E3; E4; E5) according to one of claims 13 to 14 in order to delay the provision of a transmission message (1511A) for the communication control device (11; 21; 31). [16] Subscriber station (10; 20; 30), further comprising a transmitting / receiving device (12; 32) connected to the bus (40) and designed to generate a digital receive signal (RXD) from the at least one signal (VDIFF) received by the bus (40), wherein the communication control device (11; 21; 31) is designed to sample and evaluate the received signal (RXD) generated by the transmitting / receiving device (12; 32) according to the predetermined frame (450; 460). [17] Bus system (1), with a bus (40), and at least one of the subscriber stations (10; 20; 30) according to one of the preceding claims, and at least one master subscriber station (20; 30) according to one of claims 9 or 15, wherein the at least one subscriber station (10; 20; 30) and the at least one master subscriber station (20; 30) are connected to one another via the bus (40) in such a way that the subscriber stations (10; 20; 30; 50) can communicate with one another serially. [18] Method for deterministic communication in a serial bus system (1), wherein the method is carried out with a subscriber station (10; 20; 30) which has a communication control device (11; 21; 31) and a pause module (152), wherein the communication control device (11; 21; 31) is designed to control communication of the subscriber station (10; 20; 30) with at least one other subscriber station (20; 30; 10) of the bus system (1) by generating a message (45; 46) based on a frame (450) and by sending the message (45; 46) to a bus (40) of the bus system (1) and by evaluating at least one signal (VDIFF; RXD) received from a bus (40) of the bus system (1) based on the frame (450), in which frame (450) the bit time (t_bt1) in a first communication phase (451) can be distinguished from a bit time (t_bt2) in a second communication phase (452), and wherein the method comprises the steps of Evaluating, with the pause module (152), at least one item of status information (ST_A) output by the communication control device (11; 21; 31) with regard to whether or not a predetermined frame (450_B) was received from the bus (40) and Generating, with the pause module (152) on the basis of a result of its evaluation, a transmission delay signal (TX_E) in order to delay or not delay the provision of a transmission message (1511A) to the communication control device (11; 21; 31), wherein the transmission message (1511A) is to be sent from the communication control device (11; 21; 31) as a message (45; 46) onto the bus (40).

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