Method and bus node for transmitting data

Abstract

The invention relates to a method for transmitting data via a bus line, in which data to be transmitted is received and inserted into respective data fields of at least a first frame and a second frame, and the first frame is transmitted simultaneously with the second frame. The invention further relates to an associated bus node of a bus system.

Description

Technical Field

[0001] The invention relates to a method for transmitting data via a bus line and to an associated bus node. Background Art

[0002] In recent years, the amount of data exchanged between components of motor vehicles has increased significantly and will increase even further in the future. Reasons for this are, for example, an increase in road safety, a reduction in fuel or electricity consumption, an increase in functions for implementing autonomous or partially autonomous driving, and an increasing demand for entertainment functions in vehicles. For example, document DE 10 2012 224 024 A1 describes a method for exchanging data between parties connected to one another via a bus system, wherein the data contain bit sequences. In this case, control bits are provided to enable error monitoring.

[0003] Data has long been exchanged between components of motor vehicles by means of CAN bus systems. Various standards have been developed for this purpose. In this case, in order to increase the data rate, the bit time is usually reduced or the number of data bits per frame is increased. However, it has been found that the scalability and flexibility of the known CAN bus systems are limited and that they no longer offer sufficient performance in the event of a further increase in the required data rate. Summary of the invention

[0004] Therefore, the object of the present invention is to provide a method for transmitting data via a bus line, which method is configured as an alternative or better than the known embodiments. The object of the present invention is also to provide an associated bus node.

[0005] According to the invention, this is achieved by a method and a bus node as claimed in the respective main claim. Advantageous configurations can be gathered, for example, from the corresponding dependent claims. The content of the claims is incorporated into the content of the description by explicit reference.

[0006] The invention relates to a method for transmitting data via a bus line, wherein the method comprises the following steps:

[0007] - receive data to be sent,

[0008] - inserting the data into corresponding data fields of at least the first frame and the second frame, and

[0009] - In each case a first frame and a second frame are sent simultaneously.

[0010] Since at least two frames can be sent simultaneously, a method of this type can be used to significantly increase the data transfer rate via the bus line compared to known embodiments.

[0011] According to an advantageous embodiment, a sequence of at least three different voltage levels is used in the transmission of the data field. This enables a particularly high data transfer rate to be achieved. For this purpose, not only two different voltage levels are used for the data transfer, but at least three different voltage levels are used. This enables a significant increase in the data transfer rate without requiring physical changes to the bus line.

[0012] By way of example, three, four, five or more different voltage levels may be used. Using more than three different voltage levels may increase the data transfer rate even further.

[0013] As an alternative to using at least three different voltage levels, for example, the number of lines can also be increased to more than one (eg by using two or more twisted pair lines), or other methods from telecommunication or wireless communication can be used.

[0014] A frame may be understood to mean in particular a plurality of bits or other data fields which are usually grouped together to form such a frame as a unit.

[0015] According to an advantageous embodiment, each frame has a checksum field, in which a checksum calculated for the data obtained in the corresponding data field is inserted. Such a checksum can be used to improve the reliability of data transmission. Therefore, a frame can contain at least data, a checksum field, header bits and optionally other information. Therefore, at least data, checksum field and / or header bits can be sent serially in one frame. Therefore, in particular, for example by modulating the security code onto the data, no overlapping signals are generated or sent.

[0016] In particular, in the case where the data fields have the same length, the total length of the checksum fields of a first frame and a second frame transmitted simultaneously can be shorter than twice the length of the checksum field of a frame. This advantageously utilizes the fact that, due to the use of at least three different voltage levels, a larger amount of data can be transmitted in parallel in the process described herein.

[0017] In particular, the data fields and / or the checksum fields of the frames may have the same length. This makes the implementation relatively simple. That is, in particular, all frames may have data fields of the same length, and / or all frames may have checksum fields of the same length. In other words, the data field and / or the checksum field in frame 1 may have the same length as the data field and / or the checksum field in frame 2; or in the case of three frames, the same length as the data field and / or the checksum field in frame 3, and so on.

[0018] In an advantageous variant, the bits of the checksum field obtained by the process described herein can be used as additional data bits. Thus, the checksum field can also be used for additional data transmission without adversely affecting reliability.

[0019] In particular, in both frames, the fields used for bus synchronization, in particular the header fields (e.g., SOF, arbitration, control fields) and the trailer fields (e.g., ACK field, EOF, IFS) may have the same length. This makes the execution of the method simpler, in particular when two or more frames are transmitted simultaneously in the context of the present invention.

[0020] As an advantageous variant, the fields used for bus synchronization (header field and trailer field) can be redefined in the second (and where applicable, 3rd, 4th, 5th, etc.) frame and used for any desired purpose. This can increase flexibility even further.

[0021] According to an advantageous embodiment, the first frame is a CAN frame for a CAN bus system having only two different voltage levels. It can also be backward compatible with such a CAN frame. This results in advantageous backward compatibility. This enables particularly simple integration into existing systems.

[0022] More generally, backward compatibility with other systems may also be provided as with CAN.In another embodiment, arrangements may be made to use conventional CAN communication and new multi-level CAN communication by hybrid operation without conventional nodes detecting error frames.

[0023] According to one embodiment, each frame comprises a header field before a data field and / or a checksum field. According to one embodiment, each frame comprises a trailer field after a data field and / or a checksum field. Thus, additional information can be transmitted.

[0024] According to one embodiment, the bits of the data field of the first frame and the bits of the data field of the second frame transmitted simultaneously are transmitted simultaneously via at least three different voltage levels. This enables particularly advantageous utilization of available hardware, for example bus lines.

[0025] In particular, two frames may be transmitted simultaneously. For example, data fields and / or checksum fields of two simultaneously transmitted frames may be transmitted simultaneously. This makes the implementation relatively simple.

[0026] According to one embodiment, it is provided that arbitration data and / or control data other than the data field and / or the checksum field are sent only in the first frame, wherein data may be sent and / or received simultaneously in both the first frame and the second frame. Thus, an additional payload or capacity for data may be provided in the second frame. In particular, only payload data, or only payload data and a checksum, may be sent in the second frame.

[0027] Arbitration and / or control data may be understood to mean in particular data which is not used to transmit payload data and possibly directly associated data (such as checksums), but is used to control the operation of the bus system or another system for data transmission. For example, the data may be used for time synchronization.

[0028] According to one embodiment, provision is made for arbitration data and / or control data to be sent in addition to the data field and / or the checksum field in both the first frame and the second frame. This enables such data to be sent together in a frame.

[0029] According to a development, it can be provided that data is also inserted into the corresponding data field of the third frame or the corresponding data field of the third frame and one or more additional frames. This can be understood as a generalization of the principle of two frames. In each case, a first frame can be sent simultaneously with the second frame and the third frame; or in each case, a first frame can be sent simultaneously with the second frame, the third frame and one or more additional frames. This enables further parallelization and increases the data transmission capacity. In an advantageous variation, the third frame and higher frames can be designed in a similar manner to the second frame. In this respect, with particular reference to the description given above, further advantages are provided by using the arbitration and control fields of the second frame, the third frame, etc. for other arbitrary purposes.

[0030] In particular, a sequence of four or more different voltage levels may be used in the transmission of the data field and / or the transmission of the checksum field. This may increase capacity even further, in particular compared to embodiments using only three voltage levels.

[0031] As an alternative, for example, one could resort to the above-mentioned concept of using multiple lines or vectoring.

[0032] In particular, the bus line used for the above method can advantageously be a CAN bus line, which makes it possible to implement the method according to the invention in existing systems. It can be in the form of a twisted pair bus line. Another type of bus line can also be used. In particular, the concepts described herein are not limited to the use of two bus lines and can be applied to buses that utilize any number of electrical or other physical signal transmission methods.

[0033] The invention further relates to a bus node of a bus system. The bus node may advantageously but not necessarily include a bus controller and in particular a bus interface. In particular, the bus interface may be designed to use at least two, three or at least four different voltage levels to send data. In particular, the bus node may be configured to perform a method as described herein. In this case, all embodiments and variants described herein may be used. In principle, any number of different voltage levels may be used.

[0034] Advantageously, a bus node of this type can be used to implement the method described herein. In particular, the bus node can receive data and process it into frames. The bus node can also receive frames that have been processed. In particular, the bus node can include a processor device and a storage device, wherein the storage device stores a program code, and when executing the program code, the processor device performs the method according to the present invention.

[0035] The following describes an additional invention. It can be used advantageously with the concept of data fields already described. However, it can also be implemented independently of this concept.

[0036] The invention relates to a method for transmitting data via a bus line.

[0037] The method comprises the following steps:

[0038] - applying at least one bias voltage as a voltage to the bus line,

[0039] - converting the data into a sequence of at least three different voltage levels, and

[0040] -Modulates the voltage level to the bias voltage.

[0041] By the method just described, the data transmission capacity of the bus line is better utilized than in the case of known methods for sending data. The known methods are typically based on the fact that only two different voltage levels are used. In contrast, in the method described in this article, at least three different voltage levels are used. This enables a higher amount of data to be transmitted simultaneously without the need to modify the bus line used.

[0042] In particular, the voltage level can be understood as a differential voltage, which indicates the difference between the corresponding current voltage and the bias voltage.

[0043] In particular, a bus line may be understood to mean a line that can transmit voltage levels to other components. In particular, the bus line may have a first conductor and a second conductor that may be electrically insulated from each other. The bias voltage may be a defined voltage that establishes a defined state on the bus line. The voltage levels for data transmission are superimposed on the bus line, or these voltage levels are modulated onto the bus line. In particular, this may mean increasing or decreasing the voltage specified by the bias voltage by modulation.

[0044] In particular, voltage is understood to mean the difference between two potentials. In the present case, in particular, this is understood to mean the difference between the potential of a conductor or another element of the bus line on the one hand and the potential of another conductor or another element of the bus line or possibly ground on the other hand. A voltage level can also be understood to mean the value by which the bias voltage is changed. In particular, the voltage levels can have different amplitudes and / or signs.

[0045] In particular, conversion is understood to mean that the incoming data determines which different voltage levels are generated in sequence. Different data generate different voltage levels. This applies in particular when considering that sufficiently large blocks of voltage levels are to be sent in succession. Conversion is considered to be a preliminary stage of modulation, that is, in modulation, the voltage levels generated or specified are used for modulation.

[0046] In particular, the modulation may generate a difference between the voltage on the first conductor and the voltage on the second conductor. This enables an advantageous data transmission.

[0047] In particular, the same bias voltage can be applied as voltage to the first conductor and the second conductor. This makes the embodiment simpler. However, in principle, different bias voltages can also be used.

[0048] In particular, the amplitude of the modulation onto the first conductor may be the same as the modulation onto the second conductor. Thus, the voltage difference between the two conductors may increase uniformly between the two conductors.

[0049] In particular, the modulation onto the second conductor can be performed with an opposite sign to the modulation onto the first conductor. This allows the voltage difference on both sides to be increased, making it easier to evaluate.

[0050] For example, the voltage on the first conductor can thus be increased by 1 V and the voltage on the second conductor can be decreased by 1 V. This results in a voltage difference of 2 V.

[0051] However, in principle, different voltage amplitudes can also be used for the conductors. For example, the voltage on the first conductor can be increased by 1 V and the voltage on the second conductor can be decreased by 2 V. This results in a voltage difference of 3 V.

[0052] According to another advantageous embodiment, the data can be converted into at least four voltage levels. The data can also be converted into more than four voltage levels. For example, the data can also be converted into five, six, seven or more voltage levels. In principle, any number of different voltage levels can be used, wherein the more different voltage levels used, the more data can be transmitted simultaneously. In principle, the use of three voltage levels has achieved the advantageous effect of increasing the data transmission capacity. Using even more voltage levels, the data transmission capacity can be even further increased.

[0053] In particular, the bus line can be a CAN bus line. The bus line can be in the form of a twisted pair bus line. However, other embodiments are also possible here, for example optical variants for data transmission (dark / bright) or using brightness increments. In principle, any number of mutually insulated wires can be used.

[0054] According to one embodiment, the voltage level that is typically modulated as a differential voltage may only be positive. It may also only be negative. This makes the embodiment simpler. As an alternative, there are also cases where one or more voltage levels may be positive and one or more voltage levels may be negative. This allows modulation in both directions. In particular, the sign relates to the effect on one conductor; for the other conductor, the sign may be opposite.

[0055] The present invention also relates to a transmitter for sending data. The transmitter comprises a bias voltage unit, which is configured to apply a corresponding bias voltage to each of one or two conductors of a bus line. The transmitter also comprises a corresponding modulation unit for each conductor, which is designed to modulate a voltage level onto the conductor. In particular, at least one modulation unit can be configured to modulate at least three different voltage levels.

[0056] In particular, the method for transmitting data that has been described can advantageously be performed by a transmitter of this type. In particular, one of the voltage levels can be zero, so that at least two non-zero voltage levels can be modulated. The amplitude of the voltage level can take any desired value as long as it is technically reasonable.

[0057] In particular, one or each modulation unit can have at least two switchable driver stages. In particular, the driver stage can be in the form of a current source. However, it can also have different embodiments. In particular, the driver stage can increase and / or decrease the voltage on the corresponding conductor. The use of at least two switchable driver stages ensures that at least two different voltage levels can be applied (in particular in addition to the bias voltage). This makes it possible to carry out the method according to the invention or to use more than two different voltage levels in general. In particular, there can also be more than two switchable driver stages.

[0058] In particular, according to one embodiment, the driver stage or current source of the first conductor can be specifically designed to increase the voltage, and the driver stage or current source of the second conductor can be specifically designed to decrease the voltage. This allows for opposite modulation of the voltage levels.

[0059] According to an alternative embodiment, one or more driver stages or current sources of the first conductor can be designed to increase the voltage, and one or more driver stages or current sources of the first conductor can be designed to reduce the voltage. The current source of the second conductor can be formed in particular in the opposite direction to the current source of the first conductor. Thus, both a voltage increase and a voltage reduction can occur on each conductor. In particular, in this case, the opposite effect can also be achieved.

[0060] In particular, the transmitter may be configured to perform a method as described herein. With respect to the method, all embodiments and variants described herein may be used. In particular, the transmitter may comprise a processor device and a storage device, wherein the storage device contains a program code, and when executing the program code, the processor device performs the method according to the invention.

[0061] So far, the sending of data has been considered in particular; in particular, the corresponding receiving of data is considered below.

[0062] The invention further relates to a method for receiving data via a bus line, wherein the method comprises the following steps:

[0063] - identifying a sequence of at least three different voltage levels which are modulated onto the bus line in a superimposed manner via a bias voltage, and

[0064] -Convert this sequence of voltage levels into data.

[0065] This corresponds to the method already described for transmitting data, wherein at least three different voltage levels can be identified and converted into data, provided that the voltage levels can be identified and converted into data in a suitable manner. As described above, the data transfer rate can therefore be significantly increased.

[0066] In particular, the bus line can have a first conductor and a second conductor which are electrically insulated from each other. In particular, the modulation can represent a difference between a voltage on the first conductor and a voltage on the second conductor. In particular, the bus line can be a CAN bus line and / or a twisted pair bus line. However, other embodiments are also possible. In this regard, reference is made to the embodiments already given above with respect to the method for sending data; these embodiments apply accordingly.

[0067] The present invention also relates to a receiver for receiving data. The receiver has a detection unit, which is configured to recognize a sequence of at least three different voltage levels, which are modulated onto one or two conductors of a bus line in a superimposed manner via a bias voltage. The receiver also has a data generation unit, which is configured to generate data based on the sequence of voltage levels.

[0068] In particular, a data generating unit of this type can generate data from a signal generated as described above. As already described, this allows increasing the data rate of the transmission.

[0069] In particular, each detection unit can have at least two comparison units, which are used to compare the voltage with corresponding reference values. In particular, the detection unit can determine the deviation from the corresponding reference value and can identify the different voltage levels mentioned above from the result. Data can be generated from this.

[0070] In particular, the receiver may be configured to perform the method for receiving data as already described. With regard to the method, all embodiments and variants described herein may be used. In particular, the receiver may comprise a processor device and a storage device, wherein the storage device stores a program code, and when executing the program code, the processor device performs the method according to the invention.

[0071] In particular, the transmitter described herein and the receiver described herein can be provided with an additional interface, for example in addition to the interfaces already present in the known CAN bus system, wherein the additional interface can be used to exchange data. This allows the increased data transmission capacity to be used simply and connected to other components, wherein such components typically send and / or receive data. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] A person skilled in the art will find further features and advantages from the exemplary embodiments described below with reference to the accompanying drawings, in which:

[0073] Figure 1 : shows a transmitter according to an embodiment,

[0074] Figure 2 : shows the signal sequence,

[0075] Figure 3 : shows a receiver according to an embodiment,

[0076] Figure 4 : shows a transmitter according to another embodiment,

[0077] Figure 5 : shows another signal sequence,

[0078] Figure 6 : shows a receiver according to another embodiment,

[0079] Figure 7 : shows a transmitter according to another embodiment,

[0080] Figure 8 : shows another signal sequence,

[0081] Fig. 9 : shows a receiver according to another embodiment,

[0082] Fig.10 : shows a transmitter according to another embodiment,

[0083] Fig.11 : shows another signal sequence,

[0084] Fig.12 : shows a receiver according to another embodiment,

[0085] Fig.13 : shows the bus nodes,

[0086] Fig.14 : shows another bus node,

[0087] Fig.15 : Two frames are shown,

[0088] Fig.16 : Two additional frames are shown, and

[0089] Fig.17 : shows the signal flow. DETAILED DESCRIPTION

[0090] Figure 1 A transmitter S according to an exemplary embodiment of the invention is shown. The transmitter S is designed to send data via a bus line B. The bus line B has two conductors, wherein a first conductor is denoted by CANH and a second conductor is denoted by CANL. Advantageously, data can be transmitted via a voltage, that is to say a potential difference, which can be present between the two conductors CANH, CANL.

[0091] On the output side of the transmitter a resistor network is shown, which in this example has five resistors Z ChH1 , Z ChH2 , Z ChL1 , Z ChL2 , Z ChHLAnd especially for simulation purposes, this resistor network will not be discussed in detail. It can be considered that the resistor is a component of the bus line B. This also applies to other figures showing this type of resistor network. A resistor R is directly arranged on the transmitter S, and a switch is arranged above the resistor, which can be used to electrically connect the two conductors CANH, CANL. In other embodiments, the switch can also be omitted in principle.

[0092] The transmitter S includes a bias voltage unit VO having a voltage source V CMM , which is connected to the two conductors CANH, CANL via two resistors R. The bias voltage unit VO can be used to apply a bias voltage to the bus line B in a basic state (that is, in particular when no data is transmitted). In other embodiments, the bias voltage unit VO can also be omitted, or generalized as an abstract block for generating a common mode voltage on the two conductors or bus lines. The payload signal can be modulated onto the bias voltage, for which purpose the transmitter S has two modulation units M, specifically one modulation unit per conductor.

[0093] In this example, each modulation unit M has two current sources. As shown, the two current sources I canh_nms ,I canh_s connected to the first conductor CANH, and two additional current sources I canl_nmg ,I canh_g The voltage can be varied using the current source I, which is a driver stage and together forms a modulation unit M at each conductor CANH, CANL. In this way, data can be transmitted via the bus line B. By providing two such current sources I for each of the two conductors CANH, CANL, not only can zeros and ones be transmitted as is the case in conventional embodiments, but the data transmission rate can also be significantly increased. This is particularly useful in Figure 2 Shown in.

[0094] In particular, references herein to current sources are used to indicate the term “modulation.” Other embodiments of the power driver may also be used.

[0095] Here, the top graph shows the time curve of the potential or voltage V(CANH) of the first conductor CANH, the middle graph shows the time curve of the potential or voltage V(CANL) of the second conductor CANL, and the bottom graph shows the time curve of the voltage difference generated. As can be easily seen, in each case, three different voltages can be applied to the two conductors CANH, CANL. This produces three different voltage differences, which are shown at the very bottom. Each of these three different voltage differences can correspond to a different sequence of zeros and ones in binary, either individually or in combination, so that a significantly higher data throughput can be achieved by the embodiments described herein compared to known embodiments without physically changing the bus line B. The three different states are shown as Figure 2 The number at the top of the .

[0096] Figure 3 A receiver E for receiving this type of signal is shown. The two wires CANH, CANL arrive here and are read out. For this purpose, a resistor R is provided on the input side, through which the two wires CANH, CANL are connected. Then, the receiver E has two comparison units V, which are each formed by an operational amplifier in the illustrated embodiment, which is connected to the first wire CANH at the positive input and to the second wire CANL via a corresponding voltage source at the negative input. However, the implementation is not limited thereto; OTA or other circuit concepts may also be used. OTA stands for operational transconductance amplifier, and refers to an amplifier that receives a voltage at the input and delivers a current at the output. Therefore, the gain is transconductance, in A / V, also referred to as Gm. The two voltage sources have different voltages, wherein in this case, the indicated values ​​of 1.0V and 3.5V are purely exemplary.

[0097] The output signals of the operational amplifiers, denoted by RX and RXT, each indicate whether the voltage difference between the two conductors is greater or less than the voltage of the voltage source shown in the respective case. Thus, not only two but three different voltage states can be distinguished, so that the reference voltage can be advantageously read out. Figure 2 described and can be Figure 1 The output signals RX, RXT of the two operational amplifiers can be supplied to a data generating device (not shown), which generates data that can be further digitally processed based on these signals. In particular, this type of further processing can be performed within a system (such as a bus node, a microcontroller or a control unit).

[0098] Refer to the following Figures 4 to 12 describe Figures 1 to 3 Modifications of the embodiments of the present invention, wherein, in each case, mainly the differences are discussed to illustrate the different functions. Figure 4 In the embodiment of FIG. 5 , not all current sources I for the individual conductors CANH, CANL act in the same direction (that is, increase the voltage or decrease the voltage), but in different directions. Therefore, in the case of the two conductors CANH, CANL, the voltage can be increased and decreased due to the corresponding current source I being switched on. Figure 5 As shown, three different states can also be achieved based on the corresponding signal sequence. As shown, three states can also be transmitted here, where Figure 2 Compared with the embodiment of FIG. 1 , the voltage level is generally shifted downward. This type of signal curve can be advantageously used to Figure 6 The receiver E shown in FIG. 1 is used to receive the Figure 3 Compared to the embodiment of FIG. 1 , only one voltage of one voltage source is different.

[0099] Figure 7 An embodiment of a transmitter S is shown, in which two current sources I are connected to each conductor CANH, CANL, which can increase the voltage in the case of the top conductor CANH and can reduce the voltage in the case of the bottom conductor CANL, wherein an additional current source I is connected in each case, which acts in the opposite direction. This allows a total of even four different states to be achieved, which can be generated in Figure 8 The signal transmission is shown by way of example in FIG. Fig. 9 The associated receiver (shown by way of example and which can be used to receive a signal sequence) has three comparison units V.

[0100] Fig.10 Another alternative embodiment is shown, in which two current sources I capable of increasing the voltage and two current sources I capable of decreasing the voltage are connected in each case to each of the conductors CANH, CANL. Thus, it is possible to generate Fig.11 The signal sequence shown by way of example in FIG. 1 and having a total of four different states can be used Fig.12 The receiver E shown is used for detection. In this case, the voltage source is omitted in one of the operational amplifiers, so that the position above or below the bias voltage can be immediately recognized. Therefore, two additional operational amplifiers or other electronic or electrical components with corresponding functions are sufficient to detect a total of four possible different levels.

[0101] It will be appreciated that in principle more than four different states (eg five, six, seven, eight or more states) may also be used.

[0102] Fig.13A bus node BK with a bus controller BC is shown. The bus controller BC can take over general control tasks. In particular, it represents a possibility to implement a data flow between the controller and the transceiver. Other embodiments are also possible.

[0103] The bus node BK also has a bus interface BS to a further unit (shown on the left and not described in detail again), wherein the bus interface BS has not only a receive line RX and a transmit line TX (as in the known embodiments), but also additional receive lines RXT and additional transmit lines TXT. The bus interface BS is therefore designed for ternary communication, that is to say that a higher data transmission can be achieved in both directions compared to the known embodiments and in particular by using three different voltage levels for the data transmission. With the bus interface BS shown here, a higher data transmission power can be advantageously used, since a connection with other components with a higher data transmission rate can also be achieved.

[0104] Fig.14 A corresponding embodiment for quaternary communication, that is to say using four different voltage levels, is shown. In this case, there are additional lines RXQ, TXQ designed for even higher data throughput.

[0105] In particular, Fig.13 A possible interface for ternary modulation (eg, using signal lines RXT / TXT) on a PHY is shown in FIG. In particular, Fig.14 A possible interface on the PHY for quad modulation (eg using signal lines RXQ / TXQ) is shown in . The interface itself can be used for both modulation variants without changes.

[0106] Fig.15 Two frames are shown, with a first frame F1 being shown at the top and a second frame F2 being shown at the bottom.

[0107] Initially, the two frames F start at the far left after "bus idle" (that is to say, an idle state on the bus line B, in which no data is transmitted). Then, the respective frame F starts with a field SOF, which marks the start of the respective frame. Then comes arbitration, in which an additional connection is established and controlled. Then, after this comes a control field, which can be used to handle general control tasks. Then, the two frames F have data fields, wherein, since in this example a quaternary modulation is used (that is to say, four different voltage levels are used), these data fields are transmitted simultaneously. This is merely exemplary in this case; for example, a ternary modulation or a different modulation can also be used. Therefore, the data transmission rate is higher than the data transmission rate possible when using binary communication, and therefore, multiple frames (in this case two frames F1, F2) can be transmitted simultaneously. Then, there follows a checksum field "CRC field", in which a checksum is transmitted to ensure correct communication. Finally, the two frames F have a respective confirmation field "ACK field", an end field "EOF", and an additional field "IFS". After the transmission of the two frames F, an idle state exists again on the bus.

[0108] The embodiments described herein can be used to transmit two frames F1, F2 simultaneously, whereas in known embodiments only one frame can be transmitted simultaneously. Therefore, significantly higher data throughput can be achieved by the embodiments described herein. This is due to the use of more than two different voltage levels.

[0109] The concept of the first frame F1 and the second frame F2 can be extended as required, that is, more frames can also be used and sent simultaneously. Then, it can also be reused, that is, in principle, the first frame F1 can be sent simultaneously with the second frame F2.

[0110] Fig.16 An alternative embodiment of this aspect is shown, in which the fields located before the data field and after the checksum field are formed in a different way in the second frame F2. These fields are freely usable, that is to say, they can also be filled with payload data. The payload data can be transmitted simultaneously with the fields shown in the first frame F1 that take on control tasks on the bus or in the communication. This can achieve an even further increase in data transmission.

[0111] Fig.17The basic data flow from the source "TX Data Source" to the sink "RX Data Sink" is shown. The data are first supplied to a controller, which divides the data into data TX and data TXQ, wherein the latter data are data that can be transmitted via quaternary communication in addition to the data that can already be transmitted in the prior art embodiments. A corresponding checksum field CRC is generated for the data. These data are packed together with their checksum fields in frames TX and TXQ and are then further processed and in particular sent. For this purpose, these data are supplied to an interface controller / transceiver, which forwards these data to a transceiver, which can also be referred to as a transmitter. Then, as described with reference to Fig.15 and Fig.16 As described above, the frames are sent together and thus arrive at bus line B, which is connected to the bus line at Fig.17 The frames are then received by the attached transceiver and supplied to the controller again via the interface controller / transceiver. At the controller, the corresponding frames are extracted, the checksum is verified, and in the event of a successful transmission being identified, the extracted data is provided to the data sink RX data sink. This generally results in a flow of data represented by a data flow (Data Flow).

[0112] By means of the embodiments described herein, significantly higher data transfer rates can be achieved overall, since more than just two voltage levels are used, wherein the additional overhead of the device is minimal.

[0113] The steps mentioned in the method according to the invention can be performed in the specified order. However, as long as it is technically reasonable, these steps can also be performed in another order. The method according to the invention can be performed in one of its embodiments (for example, in a specific set of steps) so that no additional steps are performed. However, in principle, additional steps, even steps not mentioned, can also be performed.

[0114] It should be noted that in the claims and the specification, features may be combined for description, for example, to facilitate understanding, but the features may also be used separately from each other. Those skilled in the art know that such features may also be combined independently of each other with other features or feature combinations.

[0115] Back-references in dependent claims may indicate preferred combinations of individual features, but do not exclude other combinations of features.

[0116] List of Reference Numerals

[0117] S Transmitter

[0118] M Modulation Unit

[0119] I Current source / driver stage

[0120] Z Resistor

[0121] R Resistor

[0122] VO bias voltage unit

[0123] B bus line

[0124] CANH First conductor

[0125] CANL Second wire

[0126] V Comparison Unit

[0127] BK bus node

[0128] BC Bus Controller

[0129] BS bus interface

[0130] F Frame

Claims

1. A method for sending data via a bus line (B), wherein: The method comprises the following steps: Receive the data to be sent, inserting the data into corresponding data fields (Data Field) of at least the first frame (F1) and the second frame (F2), and In each case, a first frame (F1) and a second frame (F2) are sent simultaneously.

2. The method according to claim 1, in, A sequence of at least three different voltage levels is used in the transmission of the data field.

3. A method according to any one of the preceding claims, in, Each frame (F) has a checksum field (CRC) in which a checksum calculated on the data obtained in the corresponding data field (Data Field) is inserted.

4. The method according to claim 3, in, In the case where the data field (Data Field) has the same length, the total length of the checksum fields (CRC) of a first frame (F1) and a second frame (F2) transmitted simultaneously is shorter than twice the length of the checksum field (CRC) of one frame.

5. The method according to any one of the preceding claims, in, These data fields (data field) and / or checksum fields (CRC) of the frames (F) have the same length.

6. The method according to any one of the preceding claims, in, These first frames ( F1 ) are CAN frames for a CAN bus system having only two different voltage levels or are backward compatible with such CAN frames.

7. The method according to any one of the preceding claims, in, Each frame (F) has a header field preceding a data field (Data Field) and / or a checksum field (CRC); and / or Each frame (F) has a trailer field located after a data field (Data Field) and / or a checksum field (CRC).

8. The method according to any one of the preceding claims, in, The bits of the data field (Data Field) of the first frame (F1) and the bits of the data field (Data Field) of the second frame (F2) transmitted simultaneously are transmitted simultaneously through the at least three different voltage levels.

9. The method according to any one of the preceding claims, in, The data field (DataField) and / or the checksum field (CRC) of two simultaneously transmitted frames (F1, F2) are transmitted simultaneously.

10. The method according to any one of the preceding claims, in, Arbitration data and / or control data other than the data field (Data Field) and / or the checksum field (CRC) are transmitted only in the first frame (F1).

11. The method according to any one of claims 1 to 9, in, Arbitration data and / or control data excluding the data field (Data Field) and / or the checksum field (CRC) are transmitted in both the first frame (F1) and the second frame (F2).

12. The method according to any one of the preceding claims, in, The data is also inserted into a corresponding data field (Data Field) of the third frame, or into a corresponding data field (Data Field) of the third frame and one or more additional frames, and In each case, a first frame (F1) is sent simultaneously with a second frame (F2) and a third frame; or in each case, a first frame (F1) is sent simultaneously with a second frame (F2), a third frame and one or more additional frames.

13. The method according to any one of the preceding claims, in, A sequence of four or more different voltage levels is used in the transmission of the data field (Data Field) and / or the transmission of the checksum field (CRC).

14. The method according to any one of the preceding claims, in, The bus line (B) is a CAN bus line, and / or Wherein, the bus line (B) is a twisted pair bus line.

15. A bus node (BK) of a bus system, The bus node comprises a bus interface (BS), in, The bus interface (BS) is designed to transmit data using at least two, three or at least four different voltage levels, and Therein, the bus node (BK) is configured to carry out the method as claimed in one of the preceding claims.

Images