Apparatus with a communication device for transmitting data via a data transmission bus, and a data transmission system with such an apparatus - Patents.com

Abstract

The present invention relates to an apparatus (1) comprising a communication device (10) and a connection device (20) for connecting the apparatus (1) to a data transmission bus (2), wherein the connection device (20) has electrical contacts (K1-K5) that are pair-connectable with corresponding bus-side electrical contacts (K1'-K5') of a bus-side connection device (20') provided on the bus (2) in order to connect the apparatus (1) to the bus (2), wherein the electrical contacts (K1-K5) include at least one data contact (K1, K2) for transmitting a data signal (CANL, CANH), a first supply contact (K3) for transmitting a first supply potential (GND), and a second supply contact (K4) for transmitting a second supply potential (VS) different from the first supply potential (GND). In order to allow simple and reliable address assignment for a number of devices (1) connected to a data transmission bus (2), it is envisaged according to the invention that the electrical contacts (K1-K5) further comprise additional contacts (K5, K5'), the device (1) is provided with a voltage measuring device (30) for measuring the potential (POT) applied to the additional contacts (K5, K5'), and the communication device (10) assigns an address to the device (1), which address is selected by (10) from a number of different predefined addresses depending on the potential (POT) measured at the additional contact (K5). Furthermore, the invention proposes a corresponding data transmission system with such a device (1).

Description

[Technical field]

[0001] The invention relates to an apparatus comprising a communication device for transmitting data via a data transmission bus, as well as to a data transmission system comprising at least one apparatus of this kind.

[0002] According to a first aspect, the present invention provides an apparatus comprising a communication device for transmitting and / or receiving data (data transmission) via a data transmission bus, and an apparatus-side connection device (e.g., a plug-in connector) for connecting the apparatus to the data transmission bus, wherein the apparatus-side connection device has electrical contacts that are pair-connectable with corresponding bus-side electrical contacts of a bus-side connection device (e.g., a mating plug-in connector) provided on the data transmission bus in order to connect the apparatus to the data transmission bus, wherein the electrical contacts include at least one data contact for transmitting a data signal, a first supply contact for transmitting a first supply potential (e.g., earth potential), and a second supply contact for transmitting a second supply potential (e.g., a supply voltage) different from the first supply potential.

[0003] Devices of this kind, and thus the realized data transmission systems, are known from the prior art in various embodiments. One example is the data transmission system, which is frequently used in vehicles, with a so-called CAN ("Controller Area Network") bus (data transmission bus), to which one or more control devices and a number of further devices, e.g. each having at least one actuator and / or at least one sensor, are connected, whereby these devices each have a CAN transceiver including a CAN interface (communication device) for transmitting and / or receiving data via the CAN bus.

[0004] In such a data transmission system, each device connected to the data transmission bus requires an address (identifier) ​​which is respectively unique, i.e. which is assigned only once in the data transmission system, in order to identify the sending device (sender) when transmitting data and / or to identify the device provided for this (receiver) when receiving data.

[0005] The measures known from the prior art for this type of address assignment consist in installing the devices at the respective intended locations (e.g. in a vehicle) with addresses that are already appropriately fixedly preset or that are set before installation in the data transmission system. The fixedly preset addresses of the devices here can, for example, be preset to correspond (in a particular assignment) to at least a part identifier, such as a "part number", which for logical reasons was defined for the devices anyway.

[0006] However, this known procedure has disadvantages, for example, when several devices, which are identical per se, for example a certain sensor model, are to be installed at several different locations in one and the same data transmission system. If these devices have the same part number, the disadvantage arises that the addresses of these devices cannot be pre-set corresponding to the part number. On the other hand, if these devices are provided with mutually different part identifiers to solve this problem, this is unsatisfactory for logical reasons.

[0007] Alternatively, in order to allow several individual instances of a particular device (e.g. a sensor or actuator model) having the same part number to be installed in different positions, it is contemplated that the device is provided with additional contacts to which, by means of a bus-side connection device, either the first or the second supply potential or no potential is applied depending on the specific installation position of the device, so that in this case, by appropriate device-side capture of each device, its own address is itself selected from three different pre-set addresses.

[0008] However, a disadvantage of this embodiment is that therefore only a maximum of three devices can be connected to the data transmission bus, and moreover here, correct assignment of addresses can fail if there is a cable break and / or a short circuit to one of the two supply potentials in the connection area of ​​one of the additional contacts.

[0009] From US Pat. No. 8,930,506, a system and a method are known for automatically assigning addresses for devices connected to a data transmission bus. In this prior art, these devices each measure one parameter (e.g. supply voltage), the value of which depends on the physical location of the device. These devices then communicate the measured parameters to a central control device, at which point an address is calculated based on each respective measurement result from these devices. Finally, the central control device assigns addresses for the individual devices based on the communicated parameters and communicates this address to the individual devices to store it there.

[0010] Disadvantages here include, for example, the requirement for a central control unit to assign individual device addresses, and furthermore, the realization of the above-mentioned communication of the assigned addresses as well as the measured parameters via a data transmission bus requires specific efforts or adaptations of the communication devices in the devices as well as of the central control unit, which are not foreseen by, for example, normal data transmission standards.

[0011] The object of the invention is to provide a novel method by which a simple and reliable address assignment can be guaranteed for a number of devices of the type mentioned at the outset that are connected to a data transmission bus.

[0012] According to a first aspect of the invention, this problem is solved in that in an apparatus of the type mentioned in the introduction, the electrical contacts further comprise an additional contact, the apparatus comprises a voltage measuring device which is configured to measure a potential applied to the additional contact with respect to a first supply potential and / or with respect to a second supply potential, and the communication device is configured to assign an address to the apparatus for transmitting and / or receiving data via a data transmission bus, the address being selected by the communication device from a plurality of different predefined addresses in dependence on the potential measured at the additional contact.

[0013] According to the invention, an automatic assignment of addresses of individual devices (e.g. sensor devices) can advantageously be realized on a data transmission bus (e.g. a CAN bus), in particular for a number of identically configured devices, e.g. with the same part number. A larger number of devices can be preferably used, without a central management mechanism being involved in the assignment and allocation of the individual device addresses. On the contrary, the assignment and allocation is handled autonomously by the individual devices. These devices preferably each determine their own address themselves immediately after their connection to the data transmission bus and can be used normally right from the start. In particular, no special "start-up procedures" or pre-adapted communication via the bus is necessary. The invention is therefore very universally applicable.

[0014] In one embodiment, the data transmission bus is a CAN bus, but the invention can also be used for any other data transmission system in which addressable data transmission, i.e. data transmission with a device address, is envisaged.

[0015] Depending on the accuracy of the device's measurement of the potential applied to the additional contact, the invention advantageously allows a very large number of different addresses to be assigned and thus a very large number of identical devices to be used in the data transmission system.

[0016] In a preferred embodiment of the present invention, for example, it is envisaged that the communication device is configured to select an address from at least four different pre-configured addresses.

[0017] An example of this: Assume that five identical sensors each measure one or more measured values ​​at five different points in the exhaust pipe of a car and communicate this to the vehicle's central control via a CAN bus. In this case, each sensor must have a unique CAN address that is uniquely defined by its respective mounting position. The CAN address required at each mounting position can be set automatically by each sensor itself depending on its position. For this purpose, each sensor measures the potential at the additional contact and then selects its address from a number of different predefined addresses depending on the measured potential.

[0018] A simple means of providing in a defined manner a potential at an additional contact of an equipment (hereinafter also referred to as "POT") consists in dividing a supply voltage VS-GND (hereinafter also referred to as "VBAT"), provided in any case by a first supply potential (hereinafter also referred to as "GND") and a second supply potential (hereinafter also referred to as "VS"), by a voltage divider formed from two or more resistors, at least one resistor of this voltage divider being arranged on the bus side.

[0019] With respect to the term "resistor" as used herein in connection with forming a voltage divider, it should be noted that this term can also generally and essentially include direct electrical line connections having a resistance so small that it is negligible in practice (R=0 Ω).

[0020] Each device can then measure, for example, the voltage between the additional contact and the first supply contact, so that the potential POT can be determined, for example as a percentage of VBAT. Thus, in the above example of five devices, for example, five differently set potentials POT1 to POT5 can be set as follows: POT1=0%VBAT (equivalent to GND) POT2=25%VBAT POT3=50%VBAT POT4=75%VBAT POT5 = 100% VBAT (equivalent to VS) It may be assumed as follows.

[0021] Then, depending on the potential POT measured at the additional contact, each device can, based on the correspondingly stored voltage threshold, assign each of its addresses ADR (for example: CAN-ID) to one of five different pre-defined addresses ADR1 to ADR5, as follows: Selection of POT=POT1:ADR=ADR1 Selection of POT=POT2:ADR=ADR2 Selection of POT=POT3:ADR=ADR3 Selection of POT=POT4:ADR=ADR4 Selection of POT=POT5:ADR=ADR5 can be selected as follows.

[0022] In the above example, where POT1 and POT5 each correspond to one of the two supply potentials GND, VS, the drawback arises in that if there is a short circuit of the additional contact to one of the two supply potentials GND, VS, then both correct address assignment and convincing error diagnosis may fail.

[0023] It is therefore envisaged in an embodiment of the invention which is preferred in this respect that the communication device is configured to evaluate as an error case the case where the measured potential POT corresponds to the first supply potential GND or to the second supply potential VS, in other words in this embodiment the values ​​of the supply potentials GND, VS are not possible (allowed) values ​​for the potential POT.

[0024] In a modification corresponding to the above five device examples, for example, five differently set potentials POT1 to POT5 are as follows: POT1=50%VBAT POT2=60%VBAT POT3 = 70% of VBAT POT4 = 80% of VBAT POT5 = 90% of VBAT It can be assumed as follows.

[0025] In one embodiment of the present invention, the communication device selects an address (ADR) assigned to a device within a potential range between a first supply potential (GND) and a second supply potential (VS) without overlapping each other, preferably in non-overlapping and preferably spaced-apart sub-ranges, and according to an assignment table in which addresses assigned to these sub-ranges are defined. It is assumed that it is configured to do so.

[0026] In the above example, such non-overlapping and spaced-apart sub-ranges and address assignments are, for example: 48% of VBAT < POT < 52% of VBAT: Selection of ADR = ADR1 58% of VBAT < POT < 62% of VBAT: Selection of ADR = ADR2 68% of VBAT < POT < 72% of VBAT: Selection of ADR = ADR3 78% of VBAT < POT < 82% of VBAT: Selection of ADR = ADR4 88% of VBAT < POT < 92% of VBAT: Selection of ADR = ADR5 It can be assumed as follows.

[0027] When a device measures a potential POT (for example, 55% of VBAT in the above example) that does not exist within a pre-set sub-range, this represents an error, and thus a proper address assignment is not possible.

[0028] In a development of this embodiment, the communication device is configured to evaluate as an error case when the measured potential (POT) does not exist within one of the pre-set sub-ranges (and, for example, to transmit an error case message via a data transmission bus using an error case address fixedly pre-set within the device). It is assumed that it is configured to do so.

[0029] In one embodiment of the present invention, it is envisaged that the manner in which the potential POT (e.g. the value of the resistors used to form the voltage divider) is provided in conjunction with the sub-ranges is such that one, two or all three of the following errors: error 1: additional contact shorted to GND, error 2: additional contact open, error 3: additional contact shorted to VBAT can be recognised and distinguished from one another based on the (erroneous) potential POT that occurs afterwards.

[0030] As already mentioned above, the potential POT can be provided at the additional contact of each device by means of a voltage divider formed from resistors, where at least one resistor of the voltage divider must be arranged on the bus side, i.e. outside the device, since this allows a respective voltage division to be realized for each device, the results of which (divided voltage or potential POT) depend on the location of the device and therefore makes it possible to select a different address ADR for each location.

[0031] Since in the device according to the invention it is envisaged that the device-side connection device is connected to a corresponding bus-side connection device in order to connect the device to a data transmission bus, the above-mentioned at least one resistor of the associated voltage divider may preferably be formed in particular in the associated bus-side connection device.

[0032] Containing the (at least one) resistor within the bus-side connection device has the advantage that no additional electrical line connection path (e.g., an additional cable or additional line in a data transmission bus line assembly) is required to connect the resistor to the bus-side connection device.

[0033] However, within the scope of the present invention, it should not be excluded that in a voltage divider (at least) one bus-side resistor is arranged outside the associated bus-side connection device (e.g. a plug-in connector of said connection device) and is connected to the associated bus-side connection device (and to the bus-side additional contacts present there) via an additional line connection.

[0034] In one embodiment of the present invention, it is envisaged that the equipment-side connection device has one or more electrical plug-in connectors (e.g., "sockets" or "plugs") that are matably connectable to corresponding bus-side electrical (opposing) plug-in connectors (e.g., "plugs" or "sockets") of the bus-side connection device in order to connect the equipment to the data transmission bus.

[0035] In this case, the at least one bus-side resistor can thereby preferably be formed in particular in a plug-in connector (counter plug-in connector) of the associated bus-side connection device in order to connect the bus-side additional contact thereto to the bus-side first supply contact or to the bus-side second supply contact.

[0036] In addition, two resistors may be formed in the associated bus-side connection device or in its plug-in connector, one of which (hereinafter also referred to as the "third resistor") connects the bus-side additional contact to the bus-side first supply contact and the other of which (hereinafter also referred to as the "fourth resistor") connects the bus-side additional contact to the bus-side second supply contact.

[0037] The circumstance that at least one resistor of the voltage divider must be arranged on the bus side, i.e. outside the associated device, does not in any way exclude that at least one resistor of the resistor assembly forming the voltage divider is arranged in the device and in particular, for example, in its device-side connection device, the latter even having special advantages in many cases, for example with regard to the possibilities and persuasiveness of error diagnosis.

[0038] In one embodiment of the invention, for example, it is envisaged that the device has a first resistor connecting the additional contact to the first supply contact and / or a second resistor connecting the additional contact to the second supply contact, the first resistor and / or the second resistor of the device being preferably arranged in this case, in particular inside the device-side connection device.

[0039] According to a further aspect of the invention the problem set out at the beginning is solved by a data transmission system, which comprises: a data transmission bus (e.g. a CAN bus) having at least one data line for transmitting a data signal, a first supply line for transmitting a first supply potential, and a second supply line for transmitting a second supply potential different from the first supply potential, at least one device of the type described in this specification, connected to a data transmission bus; a bus-side connection device provided on the data transmission bus (2) for each device connected to the data transmission bus and having bus-side electrical contacts, the bus-side electrical contacts including at least one bus-side data contact for transmitting a data signal and connected in a pair with a corresponding electrical contact of the device-side connection device of each device in order to connect each device to the data transmission bus, a bus-side first supply contact for transmitting a first supply potential, a bus-side second supply contact for transmitting a second supply potential, and a bus-side additional contact; Here, the data transmission system further comprises, for each of at least one bus side connection device provided on the data transmission bus: a resistor (hereinafter also referred to as the “third resistor”) connecting the bus-side additional contact of the associated bus-side connection device to the bus-side first supply contact of the associated bus-side connection device, and / or a resistor (hereinafter also referred to as a fourth resistor) for connecting the bus-side additional contact of the associated bus-side connection device to the bus-side second supply contact of the associated bus-side connection device, Here, when a plurality of bus-side connection devices are provided on the data transmission bus, the respective resistor assemblies formed from the respective third resistors and / or the respective fourth resistors are all different from one another.

[0040] The embodiments and special configurations described in this specification for the device according to the invention may, individually or in any combination, be envisaged in an analogous manner as embodiments or special configurations of the data transmission system according to the invention, and vice versa.

[0041] In one embodiment, it is envisaged that at least one bus-side connection device each has one or more bus-side electrical plug-in connectors which are pair-connectable to corresponding electrical plug-in connectors of the equipment-side connection device of each equipment in order to connect each equipment to the data transmission bus.

[0042] In one embodiment, it is envisaged that the resistor assembly formed from the third resistor and / or the fourth resistor is at least partly, in particular completely, formed within the associated bus-side connection device.

[0043] The device-side connection device and the bus-side connection device may each have one or more electrical plug-in connectors, which may be interconnected in pairs to connect the associated devices to the data transmission bus.

[0044] In one embodiment variant, for each device connected to the data transmission bus, the connection devices provided on the device side and on the bus side are each implemented by only one plug-in connector, which each (at least) contains all the electrical contacts required within the scope of the invention, i.e. at least one data contact, a first supply contact, a second supply contact and an additional contact.

[0045] In another embodiment variant, the connection devices to be interconnected for each device are respectively implemented by a plurality of plug-in connectors or alternatively by a plug-in connector and at least one other type of electrical connection device. In particular, for example, it is considered to implement the connections between the first supply contacts (potential GND) and / or the connections between the second supply contacts (potential VS) structurally separately from the remaining contact connections of the data transmission system.

[0046] For example, in particular in a vehicle, an on-board power supply network may be provided anyway, for example for distributing a supply voltage (e.g. battery voltage), which has lines for distributing a first and / or a second supply potential. In so far as this, such an on-board power supply network may possibly supply one or more devices used within the scope of the invention with the potential GND and / or the potential VS, and is therefore a functional component of a data transmission bus within the meaning of the invention. Furthermore, in cases where the potential GND is identical to the "earth potential" which in the vehicle is anyway distributed, for example via the (metallic) vehicle body, it should not be excluded that one or more devices are supplied with the potential GND by a direct electrical connection with an adjacent part of this vehicle body.

[0047] In one embodiment, it is envisaged that the data transmission system further comprises a control device connected to the data transmission bus and having a communication device for transmitting and / or receiving data via the data transmission bus, wherein for each bus-side connection device provided on the data transmission bus, a resistor assembly formed respectively from the third resistor and / or the fourth resistor is formed at least partially, in particular completely, in the control device and connected to the associated bus-side connection device via an additional line.

[0048] Use of suitable devices within the scope of the present invention arises, for example, for data transmission systems in vehicles, where the devices envisaged by the present invention can be or have, for example, sensors (e.g. sensors for exhaust gas aftertreatment, battery monitoring, hydrogen measurement, etc.) and / or actuators (e.g. actuators for operating mechanically adjustable interior or exterior parts, pumps such as coolant pumps, ventilators, etc.).

[0049] In the following, the invention will be further explained by way of example and with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0050] [Figure 1]FIG. 1 is a schematic diagram showing an apparatus according to a first embodiment. [Diagram 2] FIG. 4 is a schematic diagram showing an apparatus according to a second embodiment. [Diagram 3] FIG. 11 is a schematic diagram showing a device connection device according to a third embodiment. [Figure 4] 1 is a schematic diagram showing a data transmission bus including a bus-side connection device for connecting devices according to a first embodiment. [Diagram 5] 1 is a schematic diagram showing a data transmission bus including a bus-side connection device for connecting devices according to a second embodiment; [Figure 6] 4 is a flowchart showing a method for automatically assigning an address after a device is connected to a data transmission bus according to a first embodiment; [Figure 7] 6 is a flowchart illustrating a method for automatically assigning addresses according to a second embodiment.

[0051] FIG. 1 shows an apparatus 1 comprising a communication device 10 for transmitting and / or receiving data via a data transmission bus (not shown in FIG. 1) and an apparatus-side connection device 20 for connecting the apparatus 1 to the data transmission bus.

[0052] In the illustrated example, the device 1 is a sensor device with a sensor 40 implemented by means of a microcontroller and used in a vehicle for measuring one or more specific measured values ​​at a location in the vehicle (e.g. measuring exhaust gas parameters in the exhaust pipe of a motor vehicle), where the communication device 10 is configured as a CAN transceiver with a CAN interface in this case for communicating the measured values ​​via a data transmission bus configured as a CAN bus in a central control device of the vehicle connected to other devices and / or similarly to the data transmission bus. The CAN transceiver and the CAN interface can here be realized by means of software and can be considered as functional components of said microcontroller.

[0053] However, deviating from the illustrated example, the communication device 10 and its corresponding data transmission bus could be envisaged according to another data transmission standard or protocol.

[0054] An equipment side connection device 20, for example an electrical plug-in connector connected to an assembly having components 10 and 40 as symbolized in FIG. 1 via an electrical line assembly (for example a connecting cable member), has electrical contacts K1 to K5 in the illustrated example, and these electrical contacts K1 to K5 can be connected in pairs with corresponding bus side electrical contacts (not shown in FIG. 1) of a bus side connection device (for example see 20' in FIG. 4) provided on the data transmission bus in order to connect the equipment 1 to the data transmission bus.

[0055] The device-side connection device 20 (plug-in connector), which is symbolized only diagrammatically as a single block in FIG. 1, may in principle be implemented within the scope of the present invention by one or more electrical plug-in connectors and / or one or more other types of electrical connection devices. All that matters is the pairwise connectability of the electrical contacts K1-K5 with the corresponding bus-side electrical contacts. In the present example, the following contacts are provided according to the CAN standard: K1: a first data contact for transmitting a data signal CANL K2: A second data contact for transmitting a data signal CANH K3: a first supply contact for transmitting a first supply potential GND K4: a second supply contact for transmitting a second supply potential VS different from GND (and thus a supply voltage VBAT=VS-GND) It is.

[0056] Furthermore, the connection device 20 still has further contacts: K5: Additional contact for transmitting potential POT It has.

[0057] The device 1 further comprises a voltage measuring device 30, which is preferably structurally combined with the components 10 and 40, for example on a common "device circuit board". At least when the device 10 is started up, the potential POT applied to the additional contact K5 is measured with the voltage measuring device 30 relative to the first supply potential GND.

[0058] The communication device 10 is configured to assign to the device 1 an address that is determined by the communication device 10 via a data transmission bus for sending and / or receiving data (data transmission), in particular here for sending measurement data obtained with the sensor 40. This address is selected from a number of different predefined addresses depending on the potential POT measured at the additional contact K5. These predefined addresses are stored for this purpose in a memory device of the communication device 10, for example in the form of a look-up table (assignment table). Preferably, the communication device 10 is configured to select the address to be assigned for the device 1 from at least four different predefined addresses.

[0059] The functional mode of this type of address allocation in the device shown in FIG. 1 is described, by way of example, in the case where device 1 is connected to a data transmission bus shown in FIG. 4 together with further devices of identical configuration (not shown).

[0060] FIG. 4 shows a data transmission bus 2 equipped with a bus-side connection device 20' for connecting devices of the type described herein.

[0061] In the following, it is assumed by way of example that the bus-side connecting device 20' shown in Fig. 4 is provided for connecting the device 1 shown in Fig. 1. For reasons of simplicity of representation, only one connecting device 20' is shown in Fig. 4, i.e. further bus-side connecting devices for connecting further devices to the data transmission bus 2 which may actually be present are not shown in Fig. 4.

[0062] For compatibility with device 1 (here the CAN standard), data transmission bus 2 consists of the following lines: L1: Data line for transmitting data signal CANL L2: Data line for transmitting data signal CANH L3: a first supply line for transmitting a first supply potential GND L4: a second supply line for carrying a second supply potential VS has.

[0063] The bus-side connection device 20' has electrical contacts K1'-K4' and an additional contact K5' electrically connected to these lines, which are connected in pairs to the corresponding electrical contacts K1-K4 and K5 of the equipment-side connection device 20 (K1' to K1, K2' to K2, etc.) when the two connection devices 20, 20' are connected together.

[0064] Here, at the additional contact K5, the supply voltage provided by the two supply potentials GND and VS (VBAT=VS-GND) is divided by means of a voltage divider, formed in the described example by two resistors R3, R4, in order to provide in a defined manner a predetermined potential POT for the device 1 or for the illustrated position on the data transmission bus 2.

[0065] In the example of FIG. 4, two resistors R3, R4 are housed within the bus-side connection device 20' as shown, where the resistor R3 is disposed between the additional contact K5' and the first supply contact K3', and the resistor R4 is disposed between the additional contact K5' and the second supply contact K4'.

[0066] The potential POT applied to the additional contact K5' and thus also to K5 results in POT=(R3 / (R3+R4))×VBAT and can therefore be preset arbitrarily within the interval [GND, VS] by a corresponding selection of the resistance values ​​of R3 and R4.

[0067] Further bus-side connection devices not shown in FIG. 4 for connecting further devices to the data transmission bus 2 may each be designed, for example, exactly similarly to the illustrated connection device 20', but in this case all differ from one another, so that the respective resistor assemblies (voltage dividers) formed from the respective third resistors (R3) and / or the respective fourth resistors (R4) and thus also the respective preset potentials (POT) are all different from one another.

[0068] As has already been further explained above for device 1, all further devices (not shown) connected to the data transmission bus 2 can then also independently assign themselves the addresses required for transmitting and / or receiving their own data based on the measurement results of the respective potentials POT.

[0069] Terminations at the strand ends of the associated data transmission bus, which are required in many applications, for example 120 Ω terminations of the lines for CANL and CANH at the beginning and end (e.g. formed by the control device) of the CAN strand, may in particular be provided in the associated bus-side connection devices (e.g. plug-in connectors) for the two associated devices, for example. Alternatively, it is conceivable to provide all devices with suitable terminations, which can be activated or deactivated individually in the individual devices by means of respective switching devices.

[0070] In the following description of further embodiments, the same reference numerals are used for components that act similarly and are supplemented by lowercase alphabets to distinguish the respective embodiments, whereby essentially only the differences from the already described embodiments are detailed, and for the remainder, reference is made here explicitly to the description of the previous embodiments.

[0071] FIG. 2 shows device 1a comprising a communication device 10a for transmitting and / or receiving data via a data transmission bus (not shown in FIG. 2) and a device-side connection device 20a for connecting device 1a to the data transmission bus.

[0072] The distinctive feature of device 1a compared to device 1 already described (FIG. 1) is that device 1a further comprises a resistor R1 connecting additional contact K5 to the first supply contact K3 and a resistor R2 connecting additional contact K5 to the second supply contact K4.

[0073] In the example of FIG. 2, the two resistors R1, R2 are structurally combined with the components 10a, 30a, 40a, as symbolized in FIG. 2, and are housed, for example, in a circuit carrier board provided for these components.

[0074] The functional mode of automatic address allocation in the device 1a shown in FIG. 2 is also described, by way of example, in the case where the device 1a is connected to the data transmission bus 2 shown in FIG. 4 together with further devices of the same configuration (not shown).

[0075] Again, the preset potential POT at the additional contact K5 for the device 1a or for its position on the data transmission bus 2 is provided by dividing the supply voltage (VBAT=VS-GND) by means of a voltage divider, however, in this case this voltage divider is formed in total from four resistors R1, R2, R3, R4.

[0076] The potential POT applied to the additional contact K5 is now as follows: POT=(R1×R3 / (R1+R3)) / ((R1×R3 / (R1+R3))+(R2×R4 / (R2+R4)))×VBAT This occurs as follows.

[0077] More specifically, the potential POT can be understood here as some arbitrary "base potential" having, for example, a value (R1 / (R1+R2))×VBAT in the interval [GND, VS], preset on the device side by the voltage dividers R1, R2, but which is still "shifted" (and therefore different for each individual device) based on the parallel connection of the bus-side voltage dividers R3, R4.

[0078] Preferably, by suitable selection of the resistance values ​​of R1 and R2 a "base potential" is provided which is in the "middle range" of the interval [GND, VS], for example at least 5% VBAT, in particular at least 10% VBAT, and for example at most 95% VBAT, in particular at most 90% VBAT.

[0079] In this case, by appropriate selection of the resistance values ​​of R3 and R4, the "shifted reference potential" (potential at the additional contact K5) can be preset arbitrarily within the section [GND, VS] by the influence of the parallel-connected bus-side voltage divider R3, R4.

[0080] An example of this: choosing resistor values ​​R1=1 kΩ and R2=3 kΩ results in a "base potential" of 25% VBAT (the same for all devices). If it is desired that the resulting potential POT for a particular device or its location should be, for example, 35% VBAT, this can be achieved by choosing resistor values ​​R3=12 kΩ and R4=4 kΩ. If the potential POT of another device should be, for example, 40% VBAT, this can be achieved, for example, with resistor values ​​R3=1 kΩ and R4=1 kΩ.

[0081] Deviating from the above example using two bus-side resistors (R3, R4), it is also possible to arbitrarily shift the base potential using only one of the two resistors (R3, R4) shown: if one wishes to shift the base potential (e.g. 25% VBAT) to a lower value (e.g. 20% VBAT), a resistor R3 appropriately selected for this purpose is sufficient, and if one wishes to shift the base potential to a higher value (e.g. 30% VBAT), a resistor R4 appropriately selected for this purpose is sufficient.

[0082] Finally, in this context, it is mentioned that for the special case where it is desired for a certain device (or its location) to have the potential POT exactly equal to the base potential, there are two possibilities: one is to select the values ​​of the bus-side resistors R3, R4 in such a way that their mutual ratio corresponds to the ratio of the values ​​of the device-side resistors R1, R2, and the other is to not provide the bus-side resistors R3, R4 for this device (so that the potential POT is developed only by the voltage division in the resistor assembly R1, R2).

[0083] An example of this: on the device side, for example on the circuit carrier (for example the "sensor board") of each device, for example a voltage divider (consisting of resistors R1, R2) is configured to provide a base potential of, for example, an average potential range of 25% VBAT. In order to arbitrarily shift this base potential in the section [GND, VS], it is sufficient to add just one further resistor to the respective bus-side connection device (on-board power grid connector), for example the following example: Device position 1: Connect the additional contact K5' to GND (R3 = 0 Ω) POT=0% VBAT=GND Device position 2: Open additional contact K5' POT=25%VBAT Device position 3: Additional contact to high impedance VBAT via R4 POT=50%VBAT Device position 4: Additional contact K5' connected to low impedance VBAT via R4 POT=75%VBAT Device position 5: Connect additional contact K5' to VBAT (R4 = 0 Ω) POT=100% VBAT=VS Examples include:

[0084] Further examples of changes to the individual values ​​of the potential POT: Device position 1: Additional contact to high impedance VBAT via R4 POT=50%VBAT Device position 2: Additional contact K5' connected to medium impedance VBAT via R4 POT=60%VBAT Device position 3: Additional contact K5' connected to medium-low impedance VBAT via R4 POT=70%VBAT Device position 4: Additional contact K5' connected to low impedance VBAT via R4 POT=80%VBAT Device position 5: Additional contact K5' to extremely low impedance VBAT via R4 POT=90%VBAT Examples include:

[0085] In the above two examples, the resistors R3 and R4 may be arranged in the associated bus-side connection device, respectively, or may be arranged, for example, in a control device and connected to the associated device or the associated device-side connection device via an additional line (e.g., a cable).

[0086] In the second example above, you will get the following error: Error 1: Additional contact shorted to GND, can be recognized at POT=0%VBAT Error 2: Additional contact open, can be recognized at POT=25%VBAT Error 3: Additional contact shorted to VBAT, can be recognized at POT=100% VBAT The error can be easily recognized.

[0087] If the device recognizes an error case of this kind (an unacceptable value of the POT), it may be envisaged, for example, that the device logs on using a further "error case" address not used for normal data transmission and transmits corresponding error information (e.g. an error code), whereby the error case is specified in more detail (e.g. by the measured value of the POT), so that, for example, another device connected to the data transmission bus (e.g. a diagnostic or control device) can immediately record the error.

[0088] Figure 3 shows a modification of the device 1a of Figure 2, where for reasons of simplicity of illustration only the device-side connection device 20b for connecting the device to a data transmission bus is shown in Figure 3. The modification compared to the already described device 1a (Figure 2) consists in that the resistors R1 and R2 forming the device-side voltage divider are arranged in the area of ​​the device-side connection device 20b, for example in an electrical plug-in connector.

[0089] FIG. 5 shows a data transmission bus 2a equipped with a bus-side connection device 20a' for connecting devices of the type described herein, for example the device 1 shown in FIG.

[0090] For compatibility with the device 1 (here the CAN standard), the data transmission bus 2a again has the lines L1 to L4 already described above with reference to FIG. 4 for transmitting the signals CANL, CANH and the potentials GND, VS, and the bus-side connection device 20a' has electrical contacts K1' to K4' electrically connected to these lines L1 to L4, as well as an additional contact K5' for providing a potential POT for a device (not shown) connected to the connection device 20a'.

[0091] Additionally, FIG. 5 shows a control device 50a with a communication device 60a, which is also connected to the data transmission bus 2a as shown and is, for example, a central control device in the vehicle and, in this context, handles control tasks in the vehicle, for example by controlling the actuation of actuator devices connected to the bus 2a and / or by interrogating measured values ​​from sensor devices connected to the bus 2a.

[0092] In contrast to the example described with reference to FIG. 4, the resistors R3, R4 forming the bus-side voltage divider are not accommodated in the bus-side connection device 20a' but (in this embodiment both) are accommodated in the control device 50a as shown, where the resistor R3 is arranged between the additional line L5 and the first supply line L3 and the resistor R4 is arranged between the additional line L5 and the second supply line L4, where the additional line L5 extends along (parallel to) the remaining bus lines L1-L4 up to the connection device 20a' and from there further into the connection device 20a' where it is electrically connected to the additional contact K5'.

[0093] Although not shown in FIG. 5 for reasons of simplicity of illustration, a connection device of the device 50a may optionally be provided with corresponding electrical contacts for connection to the lines of the bus 2a (in which case resistors R3, R4 may each be arranged between the corresponding contacts of such a connection device).

[0094] Furthermore, in Fig. 5 further bus-side connection devices actually present for connecting further devices to the data transmission bus 2a have been omitted for reasons of simplicity of illustration. It should be noted in this context that for such further bus-side connection devices the resistors R3, R4 forming a respective bus-side voltage divider may likewise be accommodated in the control device 50a and may be connected to the associated further bus-side connection device and to further contacts provided therein by means of further electrical connections, such as respective further lines (e.g. running parallel to the remaining bus lines).

[0095] A plurality of devices of the type described in this specification, for example a plurality of devices according to one of the embodiments of Figures 1, 2 and 3, together with the associated data transmission bus to which they are connected (and possibly also at least one further device, in particular a control device, which has, independently of them, for example, a fixedly pre-set device address) form a data transmission system in which these devices can preferably assign themselves addresses for communication via the data transmission bus.

[0096] A suitable use of the invention occurs, for example, in vehicles or other machines with an internal combustion engine, where exhaust gas aftertreatment systems with several different catalytic converters are installed and where there is a need to measure measurement variables such as NOx content and / or lambda at up to five consecutive points in the exhaust gas path and communicate them to a control device. In this case, devices configured as sensor devices may be required, for example, at the following points: (1) at the start of the exhaust gas path (raw exhaust gas), (2) at a point downstream of the pre-catalyst, (3) at a point downstream of the storage catalyst, (4) at a point downstream of the first SCR catalyst, (5) at a point downstream of the second SCR / shutoff catalyst. By using the invention, it is possible to use sensor devices that are preferably configured completely identically (and therefore, for example, have the same part number) at such different points in the exhaust gas path.

[0097] Since in practice it may happen that cables break, resistors are damaged, etc., it is advantageous within the scope of the present invention if the control (e.g. the control device mentioned above) plausibly checks the automatically assigned addresses of the individual devices. Insofar as the individual devices are sensor devices, such a plausibility check can be carried out, for example, on the basis of measured values ​​supplied by the associated sensors. If several devices are, for example, identically constructed sensor devices, but are arranged at different points in the vehicle (for example at different points along the exhaust path), the plausibility check can be carried out, for example, on the basis of the temperatures measured by the respective devices (insofar as different temperatures can be estimated, for example, at different points). Also, for example, modelling (taking into account physical variables such as temperature, heating power, etc.) can be envisaged in the control for the prediction of such measured values, so that here it is also possible to carry out a plausibility check on the basis of a comparison between measured values ​​and modelled values.

[0098] FIG. 6 shows, by way of example, a possible flow of a method for automatically allocating addresses in a device of the type described herein, the operations of which are performed by control software running within the device.

[0099] The method starts in step S0, where the relevant device is connected to the data transmission bus and is supplied with the supply potentials GND, VS and thus the supply voltage VBAT (=VS-GND).

[0100] In step S1, the device is initialized and the control software is started. In step S2, a measurement of the potential POT at the additional contact of the device-side connecting device is performed, for example as a voltage measurement with respect to a first supply potential GND. In step S3, in this example, the ratio "ratio" between the potential difference POT-GND (result of the voltage measurement in step S2) on the one hand and the supply voltage VBAT (=VS-GND) on the other hand is determined using the following relationship: ratio=(POT-GND) / (VS-GND) This is carried out in accordance with:

[0101] In step S4, it is checked whether the value of "ratio" is within the permissible range for this purpose. If so, the process proceeds to step S5, in which a proper address ADR for the device is assigned depending on the value, and then to step S6, in which the data transmission operation of the device is started using the preset device address ADR.

[0102] However, if the value of "ratio" is not within the acceptable range for this, processing returns to step S1.

[0103] Figure 7 shows a modification of the method for address allocation compared to the example of Figure 6. Steps S0 to S6 correspond to steps S0 to S6 already described with reference to Figure 6.

[0104] However, the difference from this is that if the value of "ratio" checked in step S4 is not within the acceptable range for this, then based on the result of the check in step S7, the process returns to step S1 until a predetermined number of times (for example, within a range of 1 to 10 times) that step S7 is reached, but if not (i.e., if step S7 is reached again after this number of times is reached), then the process is expected to proceed to step S8.

[0105] In step S8, an allocation of a predetermined "error case" address for the device is performed, then in step S9, a sending of a predetermined "error case" message is performed using the pre-configured error case address. In one embodiment, the error case message contains information on at least one detail of the error case, in particular, one or more values ​​of the ratio "ratio" determined by the device.

[0106] By receiving and evaluating the error case message by another device connected to the data transmission bus (which may for example be a device connected dedicated to error diagnosis or for example a control device of the type mentioned above), the occurrence of an error case can be recognized, preferably immediately after the connection of the relevant device.

[0107] By using the invention and the described embodiments, a data transmission system with autonomous address assignment on the device side can preferably be realized. Such a system and the data transmission bus used here, e.g. a CAN bus, can preferably be used in vehicles or other technical devices such as machines.

[0108] In summary, the present invention proposes an apparatus (1) comprising a communication device (10) and a connection device (20) for connecting the apparatus (1) to a data transmission bus (2), wherein the connection device (20) has electrical contacts (K1-K5) that are pair-connectable with corresponding bus-side electrical contacts (K1'-K5') of a bus-side connection device (20') provided on the bus (2) in order to connect the apparatus (1) to the bus (2), wherein the electrical contacts (K1-K5) include at least one data contact (K1, K2) for transmitting a data signal (CANL, CANH), a first supply contact (K3) for transmitting a first supply potential (GND), and a second supply contact (K4) for transmitting a second supply potential (VS) different from the first supply potential (GND). In order to allow a simple and reliable address assignment for a number of devices (1) connected to the data transmission bus (2), it is envisaged that the electrical contacts (K1-K5) further comprise an additional contact (K5), the device (1) is provided with a voltage measuring device (30) for measuring the potential (POT) applied to the additional contact (K5, K5'), and the communication device (10) assigns an address to the device (1), which address is selected by (10) from a number of different predefined addresses depending on the potential (POT) measured at the additional contact (K5). Furthermore, the invention proposes a corresponding data transmission system with such a device (1).

Claims

1. An apparatus (1) comprising a communication device (10) for transmitting and / or receiving data via a data transmission bus (2) and an apparatus-side connection device (20) for connecting the apparatus (1) to the data transmission bus (2), the device-side connection device (20) has electrical contacts (K1-K5) that can be connected in pairs to corresponding bus-side electrical contacts (K1'-K5') of a bus-side connection device (20') provided on the data transmission bus (2) in order to connect the device (1) to the data transmission bus (2); In a device (1), the electrical contacts (K1-K5) include at least one data contact (K1, K2) for transmitting a data signal (CANL, CANH), a first supply contact (K3) for transmitting a first supply potential (GND), and a second supply contact (K4) for transmitting a second supply potential (VS) different from the first supply potential (GND), - said electrical contacts (K1 to K5) further comprise an additional contact (K5); said device (1) comprises a voltage measuring device (30) configured to measure the potential (POT) applied to said additional contacts (K5, K5') with respect to said first supply potential (GND) and / or with respect to said second supply potential (VS), - device (1), characterized in that the communication device (10) is configured to assign an address to the device (1) for transmitting and / or receiving data via the data transmission bus (2), the address being selected by the communication device (10) from a plurality of different pre-defined addresses depending on the potential (POT) measured at the additional contact (K5).

2. 2. The apparatus (1) according to claim 1, wherein the communication device (10) is configured to select an address from at least four different predefined addresses.

3. 3. The device (1) according to claim 1 or 2, wherein the communication device (10) is configured to evaluate as an error case a case in which the measured potential (POT) corresponds to the first supply potential (GND) or to the second supply potential (VS).

4. 4. The device (1) according to claim 1, wherein the communication device (10) is configured to select an address to be assigned to the device (1) according to an assignment table in which non-overlapping and preferably mutually spaced sub-ranges within a potential range between the first supply potential (GND) and the second supply potential (VS) are defined, as well as the addresses to be assigned to each of these sub-ranges.

5. The device (1) according to any one of claims 1 to 4, wherein the device-side connection device (20) has one or more electrical plug-in connectors that can be matably connected to corresponding bus-side electrical plug-in connectors of the bus-side connection device (20') in order to connect the device (1) to the data transmission bus (2).

6. The device (1) comprises: a first resistor (R1) connecting said additional contact (K5) to said first supply contact (K3), and / or The device (1) according to any one of the preceding claims, further comprising a second resistor (R2) connecting the additional contact (K5) to the second supply contact (K4).

7. A data transmission system, comprising: a data transmission bus (2) having at least one data line (L1, L2) for transmitting data signals (CANL, CANH), a first supply line (L3) for transmitting a first supply potential (GND) and a second supply line (L4) for transmitting a second supply potential (VS) different from the first supply potential (GND), - at least one device (1) according to any one of claims 1 to 6, connected to said data transmission bus (2); a bus-side connection device (20') provided on the data transmission bus (2) for each device (1) connected to the data transmission bus (2) and having bus-side electrical contacts (K1' to K5'), the bus-side electrical contacts (K1' to K5') including at least one bus-side data contact (K1', K2') for transmitting the data signal (CANL, CANH) and connected in pairs with the corresponding electrical contacts (K1 to K5) of the device-side connection device (20) of each device (1) in order to connect each device (1) to the data transmission bus (2), a bus-side first supply contact (K3') for transmitting the first supply potential (GND), a bus-side second supply contact (K4') for transmitting the second supply potential (VS), and a bus-side additional contact (K5'); Furthermore, for each of at least one of the bus side connection devices (20') provided on the data transmission bus (2), a third resistor (R3) connecting said bus-side additional contact (K5') of the associated bus-side connection device (20') to said bus-side first supply contact (K3') of the associated bus-side connection device (20'), and / or a fourth resistor (R4) connecting said bus-side additional contact (K5') of the associated bus-side connection device (20') to said bus-side second supply contact (K4') of the associated bus-side connection device (20'); In this data transmission system, when a plurality of bus side connection devices (20') are provided on the data transmission bus (2), the respective resistor assemblies formed from the respective third resistors (R3) and / or the respective fourth resistors (R4) are all different from each other.

8. 8. The data transmission system according to claim 7, wherein at least one of the bus side connection devices (20') has one or more bus side electrical plug-in connectors that are pair-connectable to corresponding electrical plug-in connectors of the device side connection device (20) of each of the devices (1) to connect the devices (1) to the data transmission bus (2).

9. 9. The data transmission system according to claim 7 or 8, wherein the resistor assembly formed from the third resistor (R3) and / or the fourth resistor (R4) is at least partially, in particular completely, formed within the associated bus-side connection device (20').

10. The data transmission system further comprises a control device (50a) connected to the data transmission bus (2a) and having a communication device (60a) for transmitting and / or receiving data via the data transmission bus (2a), 9. The data transmission system according to claim 7 or 8, wherein for each bus-side connection device (20') provided on the data transmission bus (2), the resistor assembly formed respectively of the third resistor (R3) and / or the fourth resistor (R4) is at least partially, in particular completely, formed in the control device (50a) and connected to the associated bus-side connection device (20') via an additional line (L5).

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