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

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 present invention relates to a device comprising a communication device for transmitting data via a data transmission bus, as well as to a data transmission system comprising at least one device of this type.

[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 connectable in pairs 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, and 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., supply voltage) different from the first supply potential.

[0003] Devices of this type, and thus the data transmission systems they realize, are known in various embodiments from the prior art. One example is a 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, each having, for example, at least one actuator and / or at least one sensor, are connected, and where 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) ​​that is unique, i.e., that is assigned only once in the data transmission system, to identify the sending device (sender) when sending data and / or to identify the device provided for this (receiver) when receiving data.

[0005] The prior art-known methods 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 can here, for example, be preset to correspond (in a particular assignment) to at least a part identifier, such as a "part number," that is defined for the devices anyway for logical reasons.

[0006] However, this known procedure has drawbacks, for example, when several identical devices, such as a specific 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 different part identifiers to solve this problem, this is insufficient for logical reasons.

[0007] Another option is to provide the device with additional contacts to allow multiple individual instances of a particular device (e.g., sensor or actuator model) with the same part number to be installed in different locations, to which the first supply potential, the second supply potential, or no potential at all is applied by means of a bus-side connection device, depending on the specific installation location of the device, so that in this case each device's appropriate device-side capture selects its own address from three different pre-set addresses.

[0008] However, a disadvantage of this embodiment is that it therefore only allows a maximum of three devices to 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] US Patent No. 8,930,506 discloses a system and method for automatically assigning addresses to devices connected to a data transmission bus. In this prior art, the devices each measure a parameter (e.g., supply voltage), the value of which depends on the physical location of the device. The devices then communicate the measured parameters to a central control unit, at which point an address is calculated based on each respective measurement result from the devices. Finally, the central control unit assigns addresses for the individual devices based on the communicated parameters and communicates these addresses to the individual devices to store them therein.

[0010] Disadvantages in this case include, for example, the requirement for a central control unit to assign individual device addresses. Furthermore, realizing 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 and of the central control unit, which are not, for example, envisaged by 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 present invention, this problem is solved in that in a device of the type mentioned in the introduction, the electrical contacts further comprise an additional contact, the device comprises a voltage measuring device which is configured to measure the potential applied to the additional contact with respect to the first supply potential and / or with respect to the second supply potential, and the communication device is configured to assign an address to the device for sending and / or receiving data via the data transmission bus, the address being selected by the communication device from a plurality of different predefined addresses depending on the potential measured at the additional contact.

[0013] According to the present invention, it is advantageously possible to realize automatic assignment of addresses for individual devices (e.g., sensor devices) on a data transmission bus (e.g., a CAN bus), especially for multiple identically configured devices, e.g., with the same part number. Preferably, a larger number of devices can be used, and no central control authority is involved in the assignment or allocation of individual device addresses. Instead, the assignment or allocation is handled autonomously by the individual devices. These devices preferably determine their own addresses immediately after their connection to the data transmission bus and can be used normally from the start. In particular, no special "start-up procedure" or pre-adapted communication via the bus is required. The present invention is therefore very versatile.

[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 device addresses, 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 large number of different addresses to be assigned, and thus a 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 is to imagine five identical sensors each measuring one or more measurements at five different points in a car's exhaust pipe and communicating 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 location. The CAN address required for each mounting location can be automatically set by each sensor depending on its location. For this purpose, each sensor measures the potential at the additional contact and then selects its address from a number of different pre-set addresses depending on the measured potential.

[0018] A simple means of providing a potential at an additional contact of a device (hereinafter also referred to as "POT") in a defined manner consists in dividing the 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 of which is 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 that have 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, from which 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, based on the correspondingly stored voltage threshold, can assign each of its addresses ADR (for example: CAN-ID) to one of five different pre-set 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] Therefore, in a preferred embodiment of the invention in this respect, it is envisaged 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 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 with each other, preferably in non-overlapping and preferably separated sub-ranges, and according to an assignment table in which addresses assigned to these sub-ranges are defined.

[0026] In the above example, such non-overlapping and separated sub-ranges and address assignments are, for example, as follows: 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 the 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, proper address assignment is impossible.

[0028] In an advanced form 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).

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

[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, in order to realize a respective voltage division for each device, the result of which (divided voltage or potential POT) depends on the device position and therefore allows a different address ADR to be selected for each position.

[0031] Since it is envisaged that in the device according to the invention, 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 at least one resistor of the associated voltage divider may preferably be formed in particular within the associated bus-side connection device.

[0032] Housing 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. the plug-in connector of said connection device) and is connected to the associated bus-side connection device (and to the additional bus-side contacts present therein) via an additional line connection.

[0034] In one embodiment of the present invention, the device-side connection device is assumed to have 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 device to the data transmission bus.

[0035] In this case, the at least one bus-side resistor can thus 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 resistor (hereinafter also referred to as the "fourth resistor") connects the bus-side additional contact to the bus-side second supply contact.

[0037] The requirement that at least one resistor of the voltage divider must be located 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 can also be located inside the device, and in particular, for example, in its device-side connection device, which in many cases even has special advantages, for example, regarding the possibility and power of error diagnosis.

[0038] In one embodiment of the present invention, for example, the device may have 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, and the first resistor and / or the second resistor of the device may in this case preferably be arranged in the device-side connection device.

[0039] According to a further aspect of the present 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 herein connected to a data transmission bus; - a bus-side connection device is provided for each device connected to the data transmission bus (2) and has 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 pairs 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 "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 fourth resistor) 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 features described herein for the device according to the invention may be envisaged in an analogous manner as embodiments or special features of the data transmission system according to the invention, individually or in any combination, 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 that are matably connectable to corresponding electrical plug-in connectors of the device-side connection device of each device in order to connect each device 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 formed at least partly, in particular completely, 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, for each device connected to the data transmission bus, the connection devices on the device side and on the bus side are each implemented by a single plug-in connector, each of which (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, it is conceivable for the connections between the first supply contacts (potential GND) and / or the connections between the second supply contacts (potential VS) to be implemented structurally separately from the remaining contact connections of the data transmission system.

[0046] For example, in particular in vehicles, an on-board power supply network may already be present, for example for distributing a supply voltage (e.g., battery voltage), which has lines for distributing a first and / or a second supply potential. To this extent, such an on-board power supply network may supply one or more devices used within the scope of the present 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 present invention. Furthermore, if the potential GND is identical to the "earth potential" that is distributed in the vehicle anyway, for example, via the (metallic) body, it should not be excluded that one or more devices may be supplied with the potential GND by a direct electrical connection to an adjacent part of this body.

[0047] In one embodiment, 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 at least partly, in particular completely, formed in the control device and connected to the associated bus-side connection device via an additional line.

[0048] A suitable use of the devices within the scope of the present invention occurs, 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. [Brief explanation of the drawings]

[0050] [Figure 1]1 is a schematic diagram showing an apparatus according to a first embodiment; [Figure 2] FIG. 10 is a schematic diagram showing an apparatus according to a second embodiment. [Figure 3] FIG. 10 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. [Figure 5] 10 is a schematic diagram showing a data transmission bus including a bus-side connection device for connecting devices according to a second embodiment. FIG. [Figure 6] 4 is a flowchart illustrating a method for automatically assigning an address after a device is connected to a data transmission bus according to a first embodiment. [Figure 7] 10 is a flowchart illustrating a method for automatically assigning addresses according to a second embodiment.

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

[0052] In the illustrated example, the device 1 is a sensor device implemented by means of a microcontroller and used in a vehicle, comprising a sensor 40 for measuring one or more specific measurements at a location in the vehicle (e.g., measuring exhaust gas parameters in the exhaust line of a motor vehicle), wherein the communication device 10 is configured as a CAN transceiver with a CAN interface in this case for communicating the measurements 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 connected data transmission buses. The CAN transceiver and the CAN interface can here be realized by means of software and can be considered as functional components of the microcontroller.

[0053] However, deviating from the illustrated example, communication device 10 and its corresponding data transmission bus could be envisioned to comply with other data transmission standards or protocols.

[0054] The equipment-side connection device 20, for example, an electrical plug-in connector connected to an assembly having components 10 and 40 as symbolized in Figure 1 via an electrical line assembly (for example, a connection 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 Figure 1) of a bus-side connection device (for example, see 20' in Figure 4) provided on the data transmission bus in order to connect the equipment 1 to the data transmission bus.

[0055] The device-side connecting device 20 (plug-in connector), which is only symbolized 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 connecting devices. What is important is only the pairwise connectability of the electrical contacts K1 to K5 with the corresponding bus-side electrical contacts. In this example, the following contacts are provided in accordance with the CAN standard: K1: First data contact for transmitting 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 the supply voltage VBAT=VS-GND). is.

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

[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 upon start-up of the device 10, 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, determined by the communication device 10, via the data transmission bus for sending and / or receiving data (data transmission), in particular for sending measurement data obtained using the sensor 40. This address is selected from a plurality 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 to 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 Figure 1 will be described, by way of example, when device 1 is connected to the data transmission bus shown in Figure 4 together with further devices of the same 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 connection 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 connection device 20' is shown in Fig. 4, i.e. further bus-side connection devices for connecting further devices to the data transmission bus 2 that 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 transmitting a second supply potential VS It has.

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

[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 Figure 4, two resistors R3 and R4 are housed within the bus-side connection device 20' as shown, where resistor R3 is located between the additional contact K5' and the first supply contact K3', and resistor R4 is located 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, therefore results from POT = (R3 / (R3 + R4)) x 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 like 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 already explained further above for device 1, all further (not shown) devices connected to the data transmission bus 2 can then also independently assign themselves the addresses required for transmitting and / or receiving their 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 control devices) of the CAN strand, may be provided in particular 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 will be used for components that function similarly and will be supplemented by lowercase letters to distinguish between the respective embodiments, whereby essentially only the differences from the previously described embodiments will be detailed, and for the remainder, reference will be made here explicitly to the description of the previous embodiments.

[0071] FIG. 2 shows a 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 the 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, on a circuit carrier board provided for these components.

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

[0075] In this case too, the potential POT preset 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 by a total of 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 It 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 divider 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] due to the influence of the parallel-connected bus-side voltage divider R3, R4.

[0080] An example of this is: choosing resistor values ​​R1=1 kΩ and R2=3 kΩ will result 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 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 it is desired to shift the base potential (e.g., 25% VBAT) to a lower value (e.g., 20% VBAT), a resistor R3 selected accordingly for this purpose is sufficient, and if it is desired to shift the base potential to a higher value (e.g., 30% VBAT), a resistor R4 selected accordingly for this purpose is sufficient.

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

[0083] An example of this is: on the device side, for example on the circuit carrier (for example "sensor board") of each device, a voltage divider (consisting of resistors R1, R2) is configured to provide a base potential in the average potential range of, for example, 25% VBAT. To arbitrarily shift this base potential in the section [GND, VS], it is sufficient to add just one further resistor to each bus-side connection device (on-board power grid connector), for example in the following example: Device position 1: Connect additional contact K5' to GND (R3 = 0Ω) 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: Connect additional contact K5' to low impedance VBAT via R4 POT=75%VBAT Device position 5: Connect additional contact K5' to VBAT (R4 = 0Ω) 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: Connect additional contact K5' to medium impedance VBAT via R4 POT=60%VBAT Device position 3: Connect additional contact K5' to medium-low impedance VBAT via R4 POT=70%VBAT Device position 4: Connect additional contact K5' to low impedance VBAT via R4 POT=80%VBAT Device position 5: Additional contact K5' connects 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, or may be arranged, for example, in a control device and connected to the associated device or associated device-side connection device via an additional line (for example, a cable).

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

[0087] If a 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 an additional "error case" address not used for normal data transmission and transmits corresponding error information (e.g. an error code), which in this case identifies the error case 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 quickly record the error.

[0088] Figure 3 shows a modification of the device 1a of Figure 2, in which, for reasons of simplicity of illustration, only the device-side connection device 20b for connecting the device to the data transmission bus is shown. 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, such as the device 1 shown in FIG.

[0090] In 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 Figure 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 to L4 up to the connection device 20a' and from there further extends 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 be arranged between the corresponding contacts of such a connection device, respectively).

[0094] Furthermore, in Figure 5, further bus-side connection devices that are actually present for connecting further devices to the data transmission bus 2a have been omitted for reasons of simplicity of illustration. In this context, it should be noted that for such further bus-side connection devices, the resistors R3, R4 forming the respective bus-side voltage dividers may likewise be accommodated in the control device 50a and may be connected to the associated further bus-side connection devices and to further contacts provided therein by means of respective further electrical connections, such as additional 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 these devices (and possibly also at least one additional device, in particular a control device, which has, independently of them, for example, a fixedly pre-set device address) are connected, form a data transmission system in which these devices can preferably assign themselves addresses for communication via the data transmission bus.

[0096] A suitable application of the present invention occurs, for example, in vehicles or other machines with internal combustion engines, where exhaust gas aftertreatment systems with several different catalytic converters are installed and 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) the start of the exhaust gas path (raw exhaust gas), (2) a point downstream of the pre-catalyst, (3) a point downstream of the storage catalyst, (4) a point downstream of the first SCR catalyst, and (5) a point downstream of the second SCR / shutoff catalyst. Using the present invention, sensor devices preferably configured identically (and therefore, for example, having the same part number) can be used at such different points in the exhaust gas path.

[0097] Since in practice cables may break, resistors may be damaged, etc., it is advantageous within the scope of the present invention for the control unit (e.g., the control device described above) to validate the automatically assigned addresses of the individual devices. If the individual devices are sensor devices, such a validation can be performed, for example, on the basis of measured values ​​provided by the associated sensors. If several devices are, for example, identically configured sensor devices but are located at different locations in the vehicle (e.g., at different locations along the exhaust path), the validation can be performed, for example, on the basis of the temperatures measured by the respective devices (as long as, for example, different temperatures can be estimated at different locations). Furthermore, for example, modeling (taking into account physical variables such as temperature, heating power, etc.) may be envisaged in the control unit for predicting such measured values, and therefore the validation can also be performed here on the basis of a comparison between measured values ​​and modeled values.

[0098] FIG. 6 shows, by way of example, a possible flow of a method for automatically assigning 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 begins 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 the 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 the following:

[0101] In step S4, it is checked whether the value of "ratio" is within the allowable range for this purpose. If it is within the allowable range, the process proceeds to step S5, where a proper address ADR for the device is assigned depending on the value, and then to step S6, where 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 allowable range for this, the process returns to step S1.

[0103] Figure 7 shows a modified example 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, in contrast to this, if the value of "ratio" checked in step S4 is not within the allowable range for this, then based on the result of the check in step S7, the process is returned to step S1 until step S7 is reached a predetermined number of times (for example, within a range of 1 to 10 times), but otherwise (i.e., if step S7 is reached again after this number of times has been reached), the process is expected to proceed to step S8.

[0105] In step S8, a predetermined "error case" address is assigned for the device, and then in step S9, a predetermined "error case" message is sent using the pre-configured error case address. In one embodiment, the error case message contains information about at least one detail of the error case, such as, 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 specifically for error diagnosis or 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 present invention and the described embodiments, it is preferably possible to realize a data transmission system with autonomous address assignment on the device side. 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 to K5) that are pair-connectable with corresponding bus-side electrical contacts (K1' to 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 to 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). To enable simple and reliable address assignment for a plurality of devices 1 connected to a 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 potentials (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 the device 10 from a plurality of different predefined addresses depending on the potential (POT) measured at the additional contact K5. Furthermore, the invention proposes a corresponding data transmission system having such devices 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 to K5) that can be connected in pairs to corresponding bus-side electrical contacts (K1' to 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 the 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), The electrical contacts (K1 to K5) further include an additional contact (K5), the device (1) comprises a voltage measuring device (30) configured to measure the potential (POT) applied to the additional contacts (K5, K5') with respect to the first supply potential (GND) and / or with respect to the second supply potential (VS), the communication device (10) is configured to assign an address to the device (1) for sending and / or receiving data via the data transmission bus (2), the address being selected by the communication device (10) from a plurality of different predefined addresses depending on the potential (POT) measured at the additional contact (K5); The communication device (10) is further configured to select the address to be assigned to the device (1) according to an assignment table, wherein the assignment table defines at least four non-overlapping and preferably mutually separated sub-ranges and the addresses respectively assigned to these sub-ranges within a potential range between the first supply potential (GND) and the second supply potential (VS), The communication device (10) is further designed to evaluate as an error case when the measured potential (POT) corresponds to the first supply potential (GND) or the second supply potential (VS). The device (1) is characterized in that

2. 2. The device (1) according to claim 1, wherein the communication device (10) is further designed to transmit an error case message via the data transmission bus (2) using an error case address preset in the device (1) when an error case occurs.

3. The device (1) of claim 2, wherein the error case message includes information regarding at least one detail of the error case.

4. The device (1) according to claim 1, 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).

5. The device (1) a first resistor (R1) connecting said additional contact (K5) to said first supply contact (K3), and / or 2. The device (1) according to claim 1, further comprising a second resistor (R2) connecting said additional contact (K5) to said second supply contact (K4).

6. The device (1) further includes a first resistor (R1) connecting the additional contact (K5) to the first supply contact (K3), and a second resistor (R2) connecting the additional contact (K5) to the second supply contact (K4); 2. The device (1) according to claim 1, wherein each of the two resistance values ​​of the first resistor (R1) and the second resistor (R2) is within a range of 5% to 95% of the sum of the two resistance values.

7. 1. 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 the bus-side additional contact (K5') of the associated bus-side connection device (20') to the 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 can be matably connected 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. 8. The data transmission system according to claim 7, wherein the resistor assembly formed from the third resistor (R3) and / or the fourth resistor (R4) is formed at least partly, in particular completely, 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); 8. The data transmission system according to claim 7, wherein for each bus-side connection device (20') provided on the data transmission bus (2), the resistor assembly formed by the third resistor (R3) and / or the fourth resistor (R4), respectively, is formed at least partly, in particular completely, in the control device (50a) and is connected to the associated bus-side connection device (20') via an additional line (L5).

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