Sensor for detecting a physical quantity with an output for connection to a control unit via a line and arrangement with this sensor

Abstract

The invention relates to a sensor (3) for detecting at least one physical quantity with an analog interface, via which at least one sensor signal with information about the detected physical quantity can be transmitted to a control unit (1) and the sensor (3) can be supplied with a supply voltage by the control unit (1), wherein a line can be connected to the interface which can be connected to an analog interface of the control unit, wherein the interface has a connection for a high potential (VCC) of the supply voltage, a connection for a low potential (GND) of the supply voltage and a connection for the sensor signal or connections for the sensor signals, wherein the sensor (3) has a coding means (32) to display coded information at the connections of the interface of the sensor (3).

Description

[0001] The invention relates to a sensor for detecting at least one physical quantity with an interface via which at least one sensor signal with information about the detected physical quantity can be transmitted to a control unit and the sensor can be supplied with an operating voltage by the control unit, wherein a line can be connected to the interface which can be connected to an analog interface of the control unit, wherein the interface has a connection for a high potential of the supply voltage, a connection for a low potential of the supply voltage and a connection for the sensor signal or connections for the sensor signals.

[0002] The invention further relates to an arrangement with such a sensor.

[0003] Arrangements comprising a sensor and a control unit are known from the prior art. Such arrangements, comprising a sensor with an analog interface and a control unit with an analog interface, typically have a pull-up or pull-down resistor connected to the signal wire in the control unit. This guarantees a defined voltage level at the control unit input in the event of an open line or when the sensor switches its output to a high impedance due to internal diagnostics. For example, an open (open) signal wire and a signal wire short-circuited to the high potential of the supply voltage deliver the same high voltage level of the supply voltage when a pull-up resistor is used.If a pull-down resistor is used between the signal wire and the low potential of the supply voltage, it is impossible to distinguish between an open signal wire and one shorted to the low potential. This concept is acceptable from a safety perspective, as it allows for the detection of a fault, but it does not allow the identification of a specific faulty wire in the line between the control unit and the sensor.

[0004] Recently, however, it has become desirable to identify an electrical fault based on the affected wire in the cable or the affected pin of the control unit. This is called "pin pointing" and is required for on-board diagnostics to help the workshop repair a specific part without further root cause analysis. In the event of a wiring harness malfunction (open or short circuit), it must be possible to identify the affected wire.

[0005] This is not possible yet.

[0006] The invention is therefore based on the object of proposing a solution with which pin pointing is fundamentally possible.

[0007] This object is achieved according to the invention in that the sensor has a coding means for displaying coded information at the terminals of the sensor's analog interface. The ability to display coded information at the sensor's terminals allows errors detected by the sensor or reported to the sensor to be displayed as information at the interface terminals. This information can then be read into the control unit and, if necessary, further processed.

[0008] Since the sensor often has to be supplied with the supply voltage from the control unit via the cable for operation, unless there is another or additional voltage supply, it is useful if the coding means of the sensor only display the information in coded form at the connection for the sensor signal or the connections for the sensor signals.

[0009] The sensor can obtain the coded information to be provided at the terminals of the interface itself, or it can be communicated to it. The sensor can have one or more means for obtaining information. Thus, as a means for obtaining information, the sensor can in particular have one or more means with which different types of faults in the line connectable to the sensor interface can be detected, in particular breaks in the wires and short circuits between two wires of the line. The sensor can also have one or more means as a means for obtaining information with which different types of faults in the sensor can be detected. However, faults can occur not only on or in the sensor, but also in the means or device that generates the physical quantity or at which the physical quantity that can be detected by the sensor occurs.Therefore, it is possible for the sensor, as a means for obtaining information, to comprise one or more means for detecting different types of errors in a means or device that generates or at which the physical quantity that can be detected by the sensor occurs.

[0010] The coding means may be suitable and configured to display the type of error detected by the error detection means or the error detection means in coded form as information at the terminals of the interface, the terminal for the sensor signal of the interface or the terminals for the sensor signals of the interface.

[0011] The at least one coding means can be suitable and configured, as soon as an error is detected which is to be indicated at the connection or connections of the interface, to set a potential at the connection or connections of the sensor interface depending on the type of error detected, wherein the potential set at the connection or the potentials set at the connections form a code by which the type of error is indicated at the interface.

[0012] A fault in the line between the sensor and the control unit can be a short circuit between the at least one wire connected to the connection for the sensor signal (signal wire) and the wire connected to the connection for the high potential of the supply voltage. In the event of such a fault, the at least one coding means can apply a first potential to another connection for the sensor signal, wherein the first potential lies in a diagnostic range. The diagnostic range can be formed by at least one interval of the voltage range between the low potential of the supply voltage and a high potential of the supply voltage. It is possible for the diagnostic range to comprise an interval from greater than 0% to 10% of the supply voltage and an interval from 90% to less than 100% of the supply voltage. The diagnostic range then comprises two intervals.

[0013] In the event of a short circuit between the signal wire and the supply voltage terminal for the low potential, the at least one coding means can apply a second potential to another terminal for the sensor signal, the second potential being in the diagnostic range.

[0014] A sensor according to the invention can be designed in such a way that a voltage outside the diagnostic range is applied to the connection for the sensor signal, - if there is an uninterrupted connection via at least one signal wire to the control unit, - without there being a short circuit between the signal wire and the wire connected to the low potential supply voltage terminal or the wire connected to the high potential supply voltage terminal, and - without the low potential wire or the high potential wire of the cable between the sensor and the control unit being interrupted.

[0015] The signal then present at the sensor signal connection can then be a signal that represents the physical quantity determined by the sensor.

[0016] A sensor according to the invention can be part of an arrangement comprising the sensor, a control unit with an analog interface, wherein the interface has a connection for a high potential of the supply voltage, a connection for a low potential of the supply voltage and a connection for the sensor signal or connections for the sensor signals, and a line with several wires, wherein the line connects the interface of the sensor to the interface of the control unit, for which purpose each connection of the sensor is connected to the corresponding connection of the control unit via a wire of the line.

[0017] In the control unit of such an arrangement, a first resistance component can be assigned to the terminal for the sensor signal or to each of the terminals for one of the sensor signals, wherein the first resistance component is a pull-up resistor or a pull-down resistor which connects the assigned terminal for the sensor signal to the terminal for the high potential of the supply voltage or to the terminal for the low potential of the supply voltage.In the control unit, a second resistance component can further be assigned to the connection for the sensor signal or to each of the connections for one of the sensor signals, wherein the second resistance component is a pull-up resistor if the first resistance component is a pull-down resistor, or a pull-down resistor if the first resistance component is a pull-up resistor, and wherein the second resistance component connects the assigned connection for the sensor signal to the connection for the high potential of the supply voltage or to the connection for the low potential of the supply voltage, and wherein the second resistance component has a higher resistance than the first resistance component.

[0018] The invention is explained in more detail with the help of the attached drawing. It shows Fig.1 a schematic representation of an example of an arrangement with a sensor according to the invention and a control unit, which are connected to each other by a line.

[0019] The figure schematically shows an arrangement comprising a control unit 1, a line 2, and a sensor 3. Both the control unit 1 and the sensor 3 have an interface with six connections, namely a connection for the high potential VCC of the supply voltage supplied to the sensor 3 by the control unit 1, a connection for the low potential GND of the supply voltage, and a connection each for a first sensor signal, a second sensor signal, a third sensor signal, and a fourth sensor signal, which are generated by the sensor and transmitted to the control unit 1 via the line 2. In variants of the invention, more or fewer connections for sensor signals can also be provided.

[0020] The sensor signals can be different, related or unrelated. They can be identical signals transmitted for redundancy. The second sensor signal can be the inverted version of the first sensor signal.

[0021] The cable 2 has six wires, namely two wires 21, 22 for the supply voltage, which are connected to the terminals of the control unit 1 and the sensor 3, a wire 23 for the first sensor signal (first signal wire), a wire 24 for the second sensor signal (second signal wire), a wire 25 for the third sensor signal (third signal wire) and a wire 26 for the fourth sensor signal (fourth signal wire).

[0022] Capacitors C1 are provided in both the control unit 1 and the sensor 3. These capacitors couple the sensor signal terminals to the GND terminals for the low potential of the supply voltage. Such capacitors can be omitted in variants of the invention. The control unit has an analog-to-digital converter 11, with which the signals present at the sensor signal terminals can be digitized. The analog-to-digital converter 11 is connected to the sensor signal terminals via low-pass filters R3, C3. The low-pass filters can also be omitted in variants of the invention or replaced by other suitable filters.

[0023] Furthermore, the well-known and in the Fig.The control unit shown in Figure 1 has pull-up resistors R11, R21, R31, and R41. The pull-up resistor R11 is assigned to the terminal for the first sensor signal and connects it to the terminal for the high potential VCC of the supply voltage. The pull-up resistor R21 is assigned to the terminal for the second sensor signal and connects it to the terminal for the high potential VCC of the supply voltage. The pull-up resistor R31 is assigned to the terminal for the third sensor signal and connects it to the terminal for the high potential VCC of the supply voltage. The pull-up resistor R41 is assigned to the terminal for the fourth sensor signal and connects it to the terminal for the high potential VCC of the supply voltage.

[0024] The resistor components R11, R21, R31, and R41 make it possible to detect the presence of a fault in line 2 or in sensor 3 without being able to determine the type or location of the fault more precisely. The resistors R11, R21, R31, and R41 provide a defined level if the sensor is not actively driving a signal. This is useful if a wire is interrupted or if the sensor itself switches off its output. With the invention, potentials in the diagnostic range are deliberately applied to the connections for the signal wires. Pull-up resistors are not relevant for this. For this reason, they could also be pull-down resistors, or pull resistors could even be omitted. Pull resistors are advantageous in the case of an interruption.

[0025] An integrated circuit 31 is provided in the sensor 3. This circuit 31 forms, among other things, one or more error detection means with which different types of errors in the line connected to the sensor interface can be detected. Furthermore, the circuit forms coding means with which error codes can be generated, which can be displayed at the terminals for the signal wires 23, 24, 25, 26 and thus transmitted to the control unit.

[0026] The following faults on line 2 can be detected using the fault detection tools: - Short circuit between wire 21 for the high potential and the first signal wire 23, - Short circuit between wire 21 for the high potential and the second signal wire 24, - Short circuit between wire 21 for the high potential and the third signal wire 25, - Short circuit between wire 21 for the high potential and the fourth signal wire 26, - Short circuit between the first signal wire 23 and the wire 22 for the low potential GND, - Short circuit between the second signal wire 24 and the wire 22 for the low potential GND, - Short circuit between the third signal wire 25 and the wire 22 for the low potential GND, - Short circuit between the fourth signal wire 26 and the wire 22 for the low potential GND, - Short circuit between the first signal wire 23 and the second signal wire 24, - Short circuit between the first signal wire 23 and the third signal wire 25, - Short circuit between the first signal wire 23 and the fourth signal wire 26, - Short circuit between the second signal wire 24 and the third signal wire 25, - Short circuit between the second signal wire 24 and the fourth signal wire 26, - Short circuit between the third signal wire 25 and the fourth signal wire 26.

[0027] The following faults on line 2 cannot be detected using the fault detection tools, as the sensor is not supplied with a supply voltage (unless there is a supply from another source): - Interruption of wire 22 for the low potential GND, - Short circuit between wire 21 for the high potential VCC and wire 22 for the low potential GND,

[0028] However, these errors can be detected in other ways. With the wiring in the control unit with pull-up / down resistors, no current will flow because, in the first case, wire 22 for the low potential GND is interrupted. The connections for the signal wires in the control unit then go through the pull-up resistors to the high potential of the supply voltage, or through the pull-down resistors to the low potential of the supply voltage. In the second case, in the case of a short circuit, it can be assumed that the power supply is entering current limiting and the voltage then drops within the source. The wire for the positive potential of the supply voltage VCC therefore has the potential GND (0V). This means that all other wires also have 0V. However, the sensor does not contribute to this.

[0029] Furthermore, it is also provided that the error detection means detect a sensor error. The detection of a sensor error can also be indicated by an error code generated by the coding means at the sensor wire terminals.

[0030] If the coding device wants to transmit an error code, it applies a potential to the sensor signal terminals of sensor 2 in an interval from 0% to 10% of the high potential VCC of the supply voltage or in an interval from 90% to 100% of the high potential VCC of the supply voltage. The applied potential lies in one of the voltage intervals collectively referred to as the diagnostic range. These are voltage intervals used by the described sensor 3 to transmit error codes and not to transmit sensor signals. The limits of the diagnostic range, here 10% and 90% of the high potential VCC, can be freely selected. Each variant can have different values. Customers want different ranges. Sensors can support different ranges. It is important that the sensor actively pulls the signal into the lower or upper diagnostic range.Where exactly this lies can be determined by the person skilled in the art implementing the invention. Sensor signals, on the other hand, lie in an interval of 10% to 90% of the supply voltage. This allows a distinction to be made between the transmission of an error code and the transmission of a sensor signal. This voltage range is referred to as the signal range. The intact sensor wires 23, 24, 25, and 26 of line 2 can be used to transmit the error codes.

[0031] The error detection means communicate the error to the coding means and the coding means generates an error code which is displayed at the signal terminals of the sensor.

[0032] Since these aforementioned errors on the control unit 1 side are transmitted via the intact, i.e. neither short-circuited nor interrupted, sensor wires 23, 24, 25, 26 of the cable 2 from the sensor 3 to the control unit 1, these errors can be detected in the control unit 1. Preferably, the error codes are selected in such a way that they can be distinguished from voltage states at the control unit terminals for the sensor signals, which occur when a - Interruption of wire 21 for the high potential VCC, - Interruption of the first signal wire 23, - Interruption of the second signal wire 24, - Interruption of the third signal wire 25 or - Interruption of the fourth signal wire 26 occurs. In these faults, the potentials at the terminals for signal wires 23, 24, 25, and 26 are determined by the pull-up resistors R11, R21, R31, and R41 in control unit 1. The following voltages (as a percentage of the supply voltage) are then present at the terminals: Table 1 Connection for the first sensor signal Connection for the second sensor signal Connection for the third sensor signal Connection for the fourth sensor signal Interruption of wire 21 for the high potential VCC 97% 97% 97% 97% Interruption of the first signal wire 23 100% 10 to 90% 10 to 90% 10 to 90% Interruption of the second signal wire 24 10 to 90% 100% 10 to 90% 10 to 90% Interruption of the third signal wire 25 10 to 90% 10 to 90% 100% 10 to 90% Interruption of the fourth signal wire 26 10 to 90% 10 to 90% 10 to 90% 100% Interruption of wire 22 for the low potential GND 100% 100% 100% 100% Short circuit between wire 21 for the high potential VCC and wire 22 for the low potential GND 0% 0% 0% 0%

[0033] If one of the signal wires is interrupted, a sensor signal can be transmitted undamaged via the intact signal wires. The control unit can detect that an interruption has occurred from the voltages present at the connections for the interrupted signal wires. The voltage at the connection of an interrupted signal wire rises to 100% of the supply voltage due to the pull-up resistor R11, R21, R31, R41. This puts it within the diagnostic range. This is already detected as an error by control unit 1. The fact that the voltage is 100% and the connection at which it is present also allows the control unit to detect the type of error.

[0034] If, on the other hand, the wire for the high potential VCC of the supply voltage is interrupted, a voltage of 97% of the supply voltage is present at all connections due to leakage currents in the control unit 1 provided in the example, which is also within the diagnostic range, so that on the one hand the presence of an error can be detected and on the other hand also the type of error.

[0035] If the wire for the low potential GND of the supply voltage is interrupted, a voltage of 100% of the supply voltage is established at all connections of control unit 1 provided in the example, which is also in the diagnostic range, so that on the one hand the presence of an error can be detected and on the other hand also the type of error.

[0036] The interruption of the wire for the high potential VCC and the interruption of the wire for the low potential GND are somewhat special here. If you really only want to interpret this digitally, then 97% and 100% are the same. Both would be interpreted as "1". In practice, it can be done this way. The value of 97% can therefore have a considerable tolerance and could, for example, be 99.5%. The interruption of the wire for the high potential VCC and the interruption of the wire for the low potential GND then look the same when interpreted digitally for the control unit. If a distinction is important here, you could, for example, install pull resistors in the sensor. Then, if the wire for the low potential GND is interrupted, a different value would be set.

[0037] If the wire for the high potential VCC of the supply voltage and the wire for the low potential GND of the supply voltage are short-circuited, a voltage of 0% of the supply voltage is present at each of the signal connections, which is also within the diagnostic range, so that on the one hand the presence of an error can be detected and on the other hand also the type of error if a suitable system architecture is selected in the control unit.

[0038] For the other errors already mentioned, the sensor's coding device sets 3 error codes, for example as shown in the following tables: Table 2 Short circuit between wire 21 for the high potential VCC and Connection for the first sensor signal Connection for the second sensor signal Connection for the third sensor signal Connection for the fourth sensor signal - the first signal wire 23 100% 0% to 10% 0% to 10% 0% to 10% - the second signal wire 24 0% to 10% 100% 0% to 10% 0% to 10% - the third signal wire 25 0% to 10% 0% to 10% 100% 0% to 10% - the fourth signal wire 26 0% to 10% 0% to 10% 0% to 10% 100%

[0039] A voltage of 100% is automatically applied to the connection for the signal wire of control unit 1 and sensor 3. This allows sensor 3 to detect that a short circuit is present, unlike an open circuit in the signal wire, where no voltage is present at the connection of sensor 3 for the corresponding signal wire. So that the control unit can distinguish between a short circuit and an open circuit, the sensor's coding device generates a potential in the range of 0% to 10% at the three connections of the non-short-circuited signal wires—i.e., in the lower interval of the diagnostic range. This then generates an error code that the control unit can use to identify the type of error. Table 3 Short circuit between wire 22 for the low potential GND and Connection for the first sensor signal Connection for the second sensor signal Connection for the third sensor signal Connection for the fourth sensor signal the first signal wire 23 0% 90 to 100% 90 to 100% 90 to 100% the second signal wire 24 90 to 100% 0% 90 to 100% 90 to 100% the third signal wire 25 90 to 100% 90 to 100% 0% 90 to 100% the fourth signal wire 26 90 to 100% 90 to 100% 90 to 100% 0%

[0040] A voltage of 0% is automatically applied to the connection for the signal wire of control unit 1 and sensor 3. This allows sensor 3 to detect that there is a short circuit between the signal wire and wire 22 for the low potential of the supply voltage. The coding device of sensor 3 then generates a potential in the range of 90% to 100% at the three connections of the non-short-circuited signal wires, i.e., in the upper interval of the diagnostic range. This then generates an error code that the control unit can use to identify the type of error. Table 4 Connection for the first sensor signal Connection for the second sensor signal Connection for the third sensor signal Connection for the fourth sensor signal Short circuit between the first signal wire 23 and the second signal wire 24 90 to 100% 90 to 100% 0% to 10% 0% to 10% Short circuit between the first signal wire 23 and the third signal wire 25 90 to 100% 0% to 10% 90 to 100% 0% to 10% Short circuit between the first signal wire 23 and the fourth signal wire 26 90 to 100% 0% to 10% 0% to 10% 90 to 100% Short circuit between the second signal wire 24 and the third signal wire 25 0% to 10% 90 to 100% 90 to 100% 0% to 10% Short circuit between the second signal wire 24 and the fourth signal wire 26 0% to 10% 90 to 100% 0% to 10% 90 to 100% Short circuit between the third signal wire 25 and the fourth signal wire 26 0% to 10% 0% to 10% 90 to 100% 90 to 100%

[0041] Sensor 3 can detect a short circuit between two signal wires 23, 24, 25, 26 using its fault detection means. These communicate the presence and type of fault to the coding means. The coding means then applies a potential in the upper interval of the diagnostic range to the terminals for the short-circuited wires, while applying a potential in the lower interval of the diagnostic range to the terminals for the other two wires (the ranges were chosen arbitrarily. It could also be the other way around. However, short-circuited wires must always receive the same level, since they are short-circuited outside the sensor). These potentials are transmitted via line 2 and are present at the signal terminals of control unit 1. From this, the control unit can then detect that a fault is present. It can also detect what type of fault is present.

[0042] Further error codes can be defined in the sensor according to the invention, which can be generated when a corresponding error occurs. For example, if a fault occurs in the sensor 3 itself, which is detected by one of the means for detecting a fault in the sensor 3, an error code can be generated in which the coding means applies a potential in the lower diagnostic range to all four terminals for the signal wires.

[0043] The error codes can be viewed as binary codes that allow the errors to be uniquely identified. If one considers only the possibility that the coding medium applies potentials in the lower or upper diagnostic range that are equal to or different from 0% and equal to or different from 100% of the supply voltage, 16 errors can be distinguished. However, since some errors involve voltages of 0% or 100% on one or more signal wires or connections of control unit 1 for signal wires, an even larger number of errors can be distinguished, which can then be detected by the control unit.

[0044] It is within the scope of the invention to be able to define further subranges or intervals within the diagnostic range, for example, 0 to 5% and 5% to 10% of the supply voltage. This would provide more options for error coding. In variants of the invention, a sensor can generate various discrete voltage levels within the diagnostic bands. This idea can be further developed as desired. For example, two connections for signal wires could be drawn into the diagnostic range to indicate to the control unit that an error code is about to occur. This is then mapped onto the other two wires in a valid range with any number of combinations. List of reference symbols 1 control unit 11 Analog-digital converter of the control unit 2 lines 21 Wire for the high potential VCC of the supply voltage 22 wire for the low potential GND of the supply voltage 23 first signal wire 24 second signal wire 25 third signal wire 26 fourth signal wire 3 Sensor 31 means of error detection 32 coding tools

Claims

[1] Sensor (3) for detecting at least one physical quantity, having an interface via which at least one sensor signal with information about the detected physical quantity can be transmitted to a control unit (1) and via which the sensor (3) can be supplied with a supply voltage by the control unit (1), wherein a line can be connected to the interface, which line can be connected to an analog interface of the control unit, wherein the interface has a connection for a high potential (VCC) of the supply voltage, a connection for a low potential (GND) of the supply voltage and a connection for the sensor signal or connections for the sensor signals, characterized by that the sensor (3) has a coding means (32) for displaying coded information at the terminals of the interface of the sensor (3). [2] Sensor (3) according to claim 1, characterized bythat the coding means (32) of the sensor (3) display the information in coded form exclusively at the connection for the sensor signal or the connections for the sensor signals. [3] Sensor (3) according to claim 1 or 2, characterized by that the sensor (3) has one or more means (31) with which different types of faults in the line (2) connectable to the interface of the sensor (3) can be detected, in particular interruptions in the wires and short circuits between two wires of the line (2). [4] Sensor (3) according to claim 1 to 3, characterized by that the sensor has one or more means (31) with which different types of errors of the sensor (3) can be detected. [5] Sensor (3) according to one of claims 1 to 4, characterized bythat the sensor (3) has one or more means (31) with which different types of errors of a means or device can be detected, which generates the physical quantity or at which the physical quantity occurs which can be detected by the sensor (3). [6] Sensor (3) according to one of claims 2 to 5, characterized by that the coding means (32) is suitable for displaying the type of error as coded information at the terminals of the interface or the terminal for the sensor signal of the interface or the terminals for the sensor signals of the interface. [7] Sensor (3) according to claim 6, characterized bythat the at least one coding means (32) is suitable and arranged, as soon as an error is detected, to set potentials at the terminals of the interface of the sensor (3) depending on the type of error detected, wherein the potentials set at the terminals form a code by which the type of error at the interface is indicated. [8] Sensor (3) according to claim 7, characterized by in that the at least one coding means (32) applies a first potential in a diagnostic range to the connection for the sensor signal in the event of a short circuit between the at least one wire connected to the connection for the sensor signal and the wire connected to the connection for the high potential of the supply voltage, the diagnostic range comprising at least one interval of the voltage range between the low potential (GND) of the supply voltage and a high potential (VCC) of the supply voltage. [9] Sensor (3) according to claim 7 or 8, characterized by in that the at least one coding means (32) applies a second potential in a diagnostic range to the connection for the sensor signal in the event of a short circuit between the at least one wire connected to the connection for the sensor signal and the wire connected to the connection for the low potential (GND) of the supply voltage at the connection for the sensor signal. [10] Sensor (3) according to one of claims 7 to 9, characterized by that the sensor (3) applies a voltage outside the diagnostic range to the sensor signal terminal, - if there is an uninterrupted connection to the control unit via at least one wire connected to the sensor signal connection and - without a short circuit of this wire with the wire connected to the low potential terminal (GND) of the supply voltage or with the wire connected to the high potential terminal (VCC) of the supply voltage and - without the low potential wire or the high potential wire (VCC) of the cable between the sensor and the control unit being interrupted. [11] Arrangement comprising a sensor (3) according to one of claims 1 to 10, a control unit (1) with an analog interface, wherein the interface has a connection for a high potential (VCC) of the supply voltage, a connection for a low potential (GND) of the supply voltage and a connection for the sensor signal or connections for the sensor signals, and a line (2) with several wires (21, 22, 23, 24, 25, 26) which connects the interface of the sensor (3) to the interface of the control unit (1), for which purpose each connection of the sensor (3) is connected to the corresponding connection of the control unit (1) via a wire (21, 22, 23, 24, 25, 26) of the line (2), characterized byin that in the control unit (1) a first resistance component is assigned to the connection for the sensor signal or to each of the connections for one of the sensor signals, wherein the first resistance component is a pull-up resistor (R11, R21, R31, R41) or a pull-down resistor which connects the assigned connection for the sensor signal to the connection for the high potential (VCC) of the supply voltage or to the connection for the low potential (GND) of the supply voltage. [12] Arrangement according to claim 11, characterized byin that in the control unit a second resistance component is assigned to the connection for the sensor signal or to each of the connections for one of the sensor signals, wherein the second resistance component is a pull-up resistor if the first resistance component is a pull-down resistor, or a pull-down resistor if the first resistance component is a pull-up resistor (R11, R21, R31, R41), and which connects the assigned connection for the sensor signal to the connection for the high potential (VCC) of the supply voltage or to the connection for the low potential (GND) of the supply voltage, wherein the second resistance component has a higher resistance than the first resistance component.

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