Intermediate connector for connecting a control unit to an Ethernet cable and method for monitoring a control unit connected to an Ethernet cable

Abstract

The invention relates to an intermediate connector (10) with a first input (10.B) and a second input (10.S), wherein the intermediate connector (10) is configured for in-line installation between an Ethernet cable (E) and a control unit (S). The intermediate connector (10) is configured for full-duplex transmission of an Ethernet signal between the first input (10.B) and the second input (10.S). It comprises a signal extraction unit (11) configured for separating and extracting at least one partial signal from the Ethernet signal based on its transmission direction. Furthermore, the intermediate connector (10) has an interface (10.1) configured for providing the at least one extracted partial signal.The invention further relates to a method for real-time monitoring of at least one control unit (S) of a vehicle supplied with an Ethernet signal via an Ethernet cable (E) in full-duplex operation by means of such an intermediate plug (10).

Description

The invention relates to an intermediate connector for connecting a control unit of a vehicle to an Ethernet cable designed for full duplex operation. The invention further relates to a method for monitoring at least one control unit connected to an Ethernet cable via such an intermediate connector.Document DE 10 2012 208 205 A1 describes a method and a device for recording data or for transmitting stimulation data which are transmitted in Ethernet-based networks of vehicles. A method for recording data is described, wherein the data is transmitted from a transmitting control device to a receiving control device of a vehicle via a communication system of the vehicle. The communication system includes an Ethernet network, wherein data is routed from a transmitting component to a receiving component of the Ethernet network via a transmission path and is to be recorded at a logging component of the Ethernet network that is not on the transmission path. The method includes configuring an intermediate component of the Ethernet network that is on the transmission path to send a copy of the data as logging data to the logging component and recording the logging data at the logging component.The document EP 2 242 100 A1 describes a plug connection module for connecting an electronic device to an Ethernet communication network. The plug-in connection module comprises a first and a second Ethernet connection for connection to at least one Ethernet network or Ethernet sub-network, and a device connection for connection to an electronic device. Furthermore, the plug connection module comprises a switching network node module, via which the two Ethernet connections and the device connection are coupled in such a way that an Ethernet frame arriving via one of the connections can be forwarded or is forwarded to at least one of the other connections.The document DE 102 42 921 A1 describes an Ethernet plug which is connected to an Ethernet terminal and whose connection to an Ethernet communication line serves. An Ethernet switch is integrated in the Ethernet plug.The document DE 10 2013 220 155 A1 describes an decoupling unit for a two-conductor field bus for reading bus messages, in which two directional couplers are provided, which output the bus signals as direction-specific or conductor-specific partial signals, which are further processed in a signal processing unit. If at least one of the partial signals can be evaluated, the signal processing unit outputs a digital bus telegram for further processing.The document DE 103 60 857 B4 describes a data bus system with a data bus and a terminal. The data bus has a first and a second data line. The terminal is connected to the data lines via a directional coupler to transmit and receive data via the data bus. The terminal has a transmitter and a receiver. The directional coupler forwards an input signal coming from the bus line to the transmitter and to the receiver and forwards an output signal going from the transmitter to the data bus to the data bus, but not to the receiver. The directional coupler has a transformer.Document US 6,496,886 B1 describes a mounting method for a printed circuit board using a directional data bus adapted for high speed data transmission, in which multi-bit data is transmitted between nodes at low cost. A wiring network for transferring single bit data is vertically incorporated into a multi-layer circuit board.The document DE 10 2017 128 249 A1 describes an arrangement for an actuator sensor interface (AS-i) fieldbus with a master, a power supply unit and a number of AS-i devices supplied by it, which are connected via a first AS-i line. A diagnostic device is signal-connected to the first AS-i line, but galvanically isolated from it. According to the invention, the diagnostic device is supplied by a second AS-i line, wherein the two AS-i lines are arranged overlapping one another by one meter, namely in such a way that their plus and minus lines are directly adjacent to one another. The diagnostic device does not transmit itself, but only listens to it.According to a first aspect, the object of the invention is to specify an improved intermediate connector which is configured for in-line assembly between an Ethernet cable and a control device and for decoupling a partial signal of a partial signal transmitted between the Ethernet cable and the control device and which enables particularly specific monitoring and targeted fault finding on a control device. This object is achieved according to the invention by an intermediate plug having the features of claim 1.According to a second aspect, the object of the invention is to specify an improved method for real-time monitoring of at least one control unit of a vehicle which is supplied with an Ethernet signal via an Ethernet cable in full-duplex operation. This object is achieved according to the invention by a method having the features of claim 6.Advantageous embodiments of the invention are the subject matter of the dependent claims.According to a first aspect of the invention, an intermediate connector has a first input and a second input and is configured for in-line assembly between an Ethernet cable and a control device. An in-line mounting is understood to mean a mounting in which the first input of the intermediate plug is connected to the Ethernet cable and the second input of the intermediate plug is connected to the control device.The intermediate connector is configured for full duplex transmission of an Ethernet signal between the first input and the second input, so that Ethernet packets directed to the control device in an in-line assembly are transmitted from the first input to the second input and Ethernet data packets transmitted by the control device are simultaneously transmitted from the second input to the first input.The intermediate plug comprises a signal decoupling unit which is configured to separate and decouple at least one partial signal from the Ethernet signal on the basis of its transmission direction. The transmission direction can be directed from the Ethernet cable to the control device or from the control device to the Ethernet cable. In other words: the signal decoupling unit couples out, as a partial signal, those data packets which are directed to the control device (RX partial signal) or couples out, as a partial signal, those data packets which are transmitted by the control device (TX partial signal). The signal decoupling unit can also be configured such that both an RX sub-signal and (separately therefrom) a TX sub-signal are decoupled.Furthermore, the intermediate plug has an interface which is configured to provide the at least one decoupled partial signal. Merely by way of example, such an interface can be designed as an Ethernet switch which outputs an RX subsignal on a first output-side data port and a TX subsignal on a second output-side data port.The proposed intermediate connector enables simple and reliable monitoring of the Ethernet packets transmitted from and / or to the control device. It is suitable in particular for recording and / or evaluating the transmitted Ethernet packets for monitoring and diagnosing the connection of the control unit established via the Ethernet cable. In comparison to a measurement and logging system fixedly installed in a vehicle or a test setup, the proposed plug connector is portable and can be used for various control units. In particular, the time for the establishment of a monitoring of the control unit and / or of the Ethernet cable can thus be reduced. In addition, the use of the plug connector is less susceptible to errors than the configuration of a permanently installed measurement and logging system.In one embodiment of the invention, the signal decoupling unit is connected to the interface via a field programmable gate array (FPGA), wherein the FPGA is configured for configurable selection and / or processing of the at least one sub-signal. This embodiment offers the advantage that programming the FPGA makes a particularly flexible monitoring adapted to the respective control device possible. The FPGA can be designed and programmed such that the Ethernet traffic is buffered at least temporarily by the plug connector. The intermediate storage can be effected selectively on the basis of configurable features, for example by selecting those data packets which contain a specific bit pattern defined by configuration / programming of the FPGA. This flexibility makes it possible to adapt the acquisition of data on the basis of the test scenarios specific to the respective control device.In addition, the FPGA enables flexible data forwarding that can be configured by programming. Such programming can provide, for example, that the data forwarding takes place depending on the transmission direction of Ethernet packets and / or on certain bit patterns embedded in the data stream. This enables a particularly specific monitoring and targeted fault finding at a control device.In particular, the use of an FPGA offers the possibility of specifically configuring an intermediate connector for a control unit and / or for a monitoring or test task before use (i.e. before the in-line assembly). The configuration or programming is particularly advantageously carried out here on a development computer or development workstation which is independent of the place of use (typically a vehicle), for example in a laboratory. This makes it possible to simplify and speed up the execution of test or monitoring tasks at the site of use. In addition, an intermediate plug, once configured (programmed), can be used repeatedly for similar test or monitoring tasks. This reduces the effort and the susceptibility to errors in the preparation of test or monitoring tasks.In one embodiment of the intermediate plug, the signal decoupling unit comprises at least one directional coupler and at least one analog front end, wherein the directional coupler is configured for the transmission-direction-dependent decoupling of a partial signal from an Ethernet signal according to a 100BASE-T1, according to a 1000BASE-T1 or a multi-Gig automotive Ethernet standard, and wherein the analog front end is configured for digitizing the at least one decoupled partial signal. 100BASE-T1, 1000BASE-T1 and Multi-Gig Automotive Ethernet standard are Ethernet standards that are particularly widely used in the automotive sector. This increases the flexibility of an intermediate plug formed in this way.The separation between a directional coupler for decoupling an analog partial signal and an analog front end for digitizing the decoupled analog partial signal enables a modular construction of the intermediate plug. This also facilitates the development and startup of such an intermediate plug and facilitates the re-useability. For example, the analog front end can be configurable for different automotive Ethernet standards by adapting the cut-off frequency of an anti-aliasing filter and the sampling frequency of an analog-to-digital converter to the respective automotive Ethernet standard.According to the invention, the interface has a plurality of data ports which are configurable for providing the at least one decoupled subsignal. For example, programming the FPGA can be used to set to which data port of an interface designed as an Ethernet switch partial signals are forwarded. This enables a particularly specific monitoring and targeted fault finding at a control device.In one embodiment, the intermediate plug comprises at least one memory which is configured for intermediate storage of the at least one decoupled partial signal. A memory may be provided, for example, at least partially by the FPGA. This allows the buffered data to be evaluated, for example a selection on the basis of predetermined (configured) bit patterns in Ethernet data packets. Thus, data already preprocessed by the intermediate plug can be provided via the interface. This reduces the bandwidth requirement of the interface and enables a particularly specific monitoring and a targeted fault finding.In one embodiment, the intermediate plug has a power supply connection which is configured to electrically supply the intermediate plug via the on-board power supply system of a vehicle. As a result, a separate external power supply unit can be dispensed with. This enables a particularly flexible, space-saving and uncomplicated use of the intermediate plug in a vehicle.According to a second aspect of the invention, in a method for real-time monitoring of at least one control unit of a vehicle supplied with an Ethernet signal via an Ethernet cable in full duplex operation, at least one intermediate connector according to the first aspect of the invention is arranged in in-line assembly between a respective Ethernet cable and a control unit and is configured for transmitting at least one decoupled partial signal to a data acquisition device.The proposed method enables flexible test and analysis scenarios. In particular, the method enables the monitoring of a plurality of control units and their cooperation. For example, by suitable configuration of the interfaces of a plurality of intermediate connectors, the respectively decoupled partial signals can be collected, stored and analyzed at a central point (for example a data logger or an evaluation unit).Exemplary embodiments of the invention are explained in more detail below with reference to drawings.The following are shown: FIG. 1 schematically shows a control device which is connected to an Ethernet cable via an intermediate connector, FIG. 2 schematically shows the signal path through a signal decoupling unit of an intermediate plug, and FIG. 3 schematically shows an analog front end for digitizing a decoupled partial signal.Corresponding parts are provided with the same reference numerals in all figures.FIG. 1 schematically shows a control device S which can be supplied via an Ethernet cable E with signals which are transmitted according to an automotive Ethernet standard which provides bidirectional signal transmission in point-to-point connections. Examples of such automotive Ethernet standards are 100BASE-T1, 1000BASE-T1, 2.5GBASE-T1, 5GBASE-T1 or further multi-Gig automotive Ethernet standards.For the mechanical and electrical connection, the Ethernet cable E has a plug E. S and the control device S has a socket S. B designed to match it. According to the prior art, for connecting the Ethernet cable E (and a device connected thereto and not shown here) to the control device S, the plug E. S is locked in the socket S. B. This solution has the disadvantage that, owing to the point-to-point topology, data which are transmitted between the control device S and the further device via the Ethernet cable E are not readily accessible. This makes it difficult, for example, to find faults when the control unit S is put into operation or developed.According to the invention, therefore, an intermediate connector 10 is provided which enables the decoupling of data which are transmitted via the Ethernet cable E. The intermediate connector 10 has a socket 10.B which is designed to be compatible with the socket S.B of the control unit S and is set up for the mechanical and electrical connection to the connector E.S of the Ethernet cable E. Furthermore, the intermediate connector 10 has a connector 10.S which is formed compatible with the connector E.S of the Ethernet cable E and is configured for the mechanical and electrical connection to the socket S.B of the control unit S. By means of the socket 10.B and the plug 10.S, the intermediate plug 10 can be inserted into the connection between the Ethernet cable E and the control device S. The housing of the intermediate plug 10 is made of robust, automobile-suitable materials.The intermediate connector 10 further has an interface 10.I. In the simplest case, the interface 10.I can be designed as a socket or as a plug and can be configured for the connection of a single external device. For example, the interface 10.I can be designed as an RJ45 socket, which is configured to receive an RJ45 plug.In the embodiment shown here, the interface 10.I is designed as a switch 10.I, which enables the connection of a plurality of external devices to the plug connector 10. Merely by way of example, an in-vehicle data logger L and a development computer R are illustrated. The in-vehicle data logger L is configured to store data packets transmitted from the interposer 10 via the switch 10.I for logging. The development computer R comprises a development environment with which data packets transmitted by the intermediate connector 10 are analyzed, for example in the manner of a protocol analyzer such as Wireshark.The intermediate plug 10 is electrically supplied via a power supply connection 10.P. The electrical supply can be effected via the on-board power supply (not shown here) of the vehicle or via an external power supply (not shown here) independent of the vehicle.In the intermediate connector 10, the signal is transmitted along the signal path between the socket 10.B (first input 10.B) and the connector 10.S (second input 10.S). Arranged along this signal path is a signal decoupling unit 11 which, in a manner explained in more detail below, separates, couples out, digitizes directional partial signals and provides them to an FPGA (field programmable gate array) 12 for digital signal processing. The FPGA 12 may include an internal memory 12 or may be connected to a memory 13 independent of the FPGA 12.The FPGA 12 is programmed such that all data packets arriving at the jack 10.B are provided as outgoing data packets at the jack 10.S and that all data packets arriving at the jack 10.S are provided as outgoing data packets at the jack 10.B. As a result, the data transmission between the Ethernet cable E and the control device S is maintained in the same way as in the case of a direct connection even when the intermediate connector 10 is connected in between.Furthermore, the FPGA 12 is set up such that, depending on the configuration, in addition to the direct transmission between the Ethernet cable E and the control device S, all or only selected data packets are exported via the interface 10.I. Such data packets can be buffered either in the FPGA 12 or in the optional memory 13 in order to improve the reliability and efficiency of the data transmission via the interface 10.I.The plug connector 10 is designed for plug-and-play installation and can be easily inserted between the Ethernet cable E and the control device S without special tools or modifications being required for this purpose. The interposer 10 may be configured in a variety of ways. For example, an endpoint to which data packets are to be transmitted may be configured. In the present exemplary embodiment, the data logger L and / or the development computer R can be configured as the end point.In one embodiment, it is also possible to specify filter criteria, on the basis of which data packets are selected for an export via the interface 10.I. It is also possible to assign an end point for exported data packets depending on certain filter criteria. Further, the FPGA 12 may be configured to provide the exported data in a particular data format. Methods for error detection and error correction can also be provided by suitable programming of the FPGA 12. The FPGA 12 thus enables the adaptation of the plug connector 10 to the respective control device S and / or to the specific requirements of test scenarios to which the control device S is to be subjected.The ease of assembly and installation of the plug connector 10 shortens the setup time and reduces the possibility of errors in configuration. A configuration is preferably carried out in a manner decoupled from the time when mounted on the vehicle, for example by means of a development environment under laboratory conditions. As a result, the correctness of the configuration can be checked particularly easily.Although only a single control device S is shown here, such an intermediate plug 10 can of course be provided in several copies for different control devices S. In this case, the data of the various control units S can also be collected at a central point (for example on a single data logger L or a single development computer R). As a result, complex test scenarios, which check the interaction of different control units S, for example, can also be implemented very easily and reliably.With reference to FIGS. 2 and 3, the signal path through the intermediate connector 10, in particular through the signal decoupling unit 11, is explained in more detail. FIG. 2 shows a directional coupler (differential directional coupler, DDC) 14 which is arranged between the socket 10.B and the plug 10.S of the intermediate plug 10. The DDC 14 is configured to filter out data packets in a direction-related manner and to provide them via an output 14.D. For example, the DDC 14 may be configured to provide data packets directed from the Ethernet cable E to the controller S. Alternatively, the DDC 14 may be configured to provide data packets directed from the controller S to the Ethernet cable E. It is also possible for a DDC 14 to be set up for the provision of both incoming and outgoing data packets (with respect to the control device S), which however are provided on a line pair of the output 14.D in each case independently of the data packets of the opposite transmission direction.FIG. 3 schematically shows an analog front end (AFE) 15 for receiving and analog signal processing a line pair of the output 14.D. The AFE 15 is provided as a printed circuit board and is connected to the output 14.D via SMA (SubMiniatur version A) connectors, which enable a particularly compact and interference-proof design.The differential input signal is amplified by a differential amplifier 15.1, which has a gain factor of approximately 23 decibels. The amplification factor of the differential amplifier 15.1 can be adjustable mechanically (by manual rotation of a potentiometer) or else electronically (by programming) in order to adapt the amplification to the respective signal level of the differential signal.The differential amplifier 15.1 is followed by an anti-aliasing filter 15.2. The anti-aliasing filter 15.2 can be designed, for example, as a Bessel filter of order 5 in order to achieve the most linear phase response possible and thus the least possible distortion of the filtered signal. The cut-off frequency of the anti-aliasing filter 15.2 can be selected or adapted depending on the interference sources to which the differential input signal provided at the output 14.D of the directional coupler 14 is exposed, and also depending on the transmission rate of the respective automotive Ethernet standard.An analog-to-digital converter 15.3 is connected downstream of the anti-aliasing filter 15.2. The sampling is controlled via a clock signal 15.4 provided by the FPGA 12 or by an external clock generator (not shown). Purely by way of example, an analog-to-digital converter 15.3 with a sampling rate of 200 megasamples per second can be selected for sampling a 100BASE-T1 signal, which corresponds to a threefold oversampling of the 100BASE-T1 signal. This allows reliable sampling of the differential input signal, which is low in quantization noise.On the output side, the AFE 15 is connected to the FPGA 12, on which the further digital signal processing takes place. For example, a design with a memory 12 of 8 megabits can be implemented on the FPGA 12, which corresponds to one megasample at a bit depth of the analog-to-digital converter 15.3 of 8 bits. Furthermore, the design implemented there can provide a UART (Universal Asynchronous Receiver-Transmitter) interface for output according to a USB (Universal Serial Bus) compliant protocol.List of reference characters10 Intermediate connector 10.B Socket, first input 10.I Interface, switch 10.P Power supply connection 10.S Plug, second input 11 Signal decoupling unit 12 FPGA (Field Programmable Gate Array), memory 13 Memory 14 Directional coupler, differential directional coupler (DDC) 14.D Output 15 Analog front end (AFE) 15.1 Differential amplifier 15.2 Anti-aliasing filter 15.3 Analog-to-digital converter 15.4 Clock signal E Ethernet cable E.S Plug L Data logger, data acquisition device R Development computer, data acquisition device S Control device S.B Socket

Claims

Intermediate connector (10) having a first input (10.B) and a second input (10.S), wherein the intermediate connector (10) - is configured for in-line assembly between an Ethernet cable (E) and a control device (S), - is configured for full-duplex transmission of an Ethernet signal between the first input (10.B) and the second input (10.S), - comprises a signal decoupling unit (11) which is configured for separating and decoupling at least one partial signal from the Ethernet signal on the basis of its transmission direction and - has an interface (10.I) which is configured for providing the at least one decoupled partial signal, characterized in that the interface (10.I) has a plurality of data ports configurable for providing the at least one decoupled partial signal.Intermediate connector (10) according to Claim 1, characterized in that the signal decoupling unit (11) is connected to the interface (10.I) via a field programmable gate array (FPGA) (12), wherein the FPGA (12) is set up for configurable selection and / or processing of the at least one partial signal.Intermediate connector (10) according to one of the preceding claims, characterized in that the signal decoupling unit (11) comprises at least one directional coupler (14) and at least one analog front end (15), wherein the directional coupler (14) is configured for the transmission-direction-dependent decoupling of a partial signal from an Ethernet signal according to a 100BASE-T1, according to a 1000BASE-T1 or a multi-Gig Automotive Ethernet standard and wherein the analog front end (15) is configured for digitizing the at least one decoupled partial signal.Intermediate connector (10) according to one of the preceding claims, characterized in that the intermediate connector (10) comprises a memory (12, 13) for temporarily storing the at least one decoupled partial signal.Intermediate connector (10) according to one of the preceding claims, characterized in that the intermediate connector (10) has a power supply connection (10.P) which is set up for the electrical supply of the intermediate connector (10) via the on-board power supply system of a vehicle.Method for real-time monitoring of at least one control unit (S) of a vehicle supplied with an Ethernet signal via an Ethernet cable (E) in full duplex operation, characterized in that at least one intermediate plug (10) according to one of the preceding claims is arranged in in-line mounting between in each case an Ethernet cable (E) and a control unit (S) and is configured for transmitting in each case at least one decoupled partial signal to a data acquisition device (L, R).

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