JP2010040049A - Device and method for detecting amount measured - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for detecting an amount measured to operate a plurality of sensors or satellite stations by individual line connection by a control apparatus. <P>SOLUTION: The device is constituted so as to detect at least one amount measured, which includes a device for detecting voltage of a supply current source (1), a serial circuit including a resistor R<SB>2</SB>and a current drain, wherein the serial circuit is arranged in parallel with a data bus, the current drain is provided so as to discharge current I<SB>B</SB>, and the current is expressed by I<SB>B</SB>=I<SB>BUS</SB>×R<SB>i</SB>/R<SB>2</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The invention relates to a device for detecting at least one measurand. Here, at least one data bus is provided by the device. This data bus is connected to at least one sensor for detecting a measured quantity. Here, a supply current is supplied to the sensor by a supply current source via a data bus. The device includes a device capable of forming an inquiry signal having a signal shape set on a data bus.

  This type of device is used, for example, in automotive control equipment. Here, the control device supplies a data bus, and a plurality of sensors are serially connected to the control device via the data bus. The control device performs open-loop control or closed-loop control of the functions of the automobile using the measured amounts detected by these sensors. This function includes, for example, a seat belt pretensioner, an air bag, an engine operating state, and the like.

  From DE 198559178 C1 a method for transmitting data in a motor vehicle is known. Here, satellite stations, for example collision sensors, are connected to the central control device using an indirect current interface. The data transmission line is here a wire-connected interface. This wire-connected interface is used on the one hand to supply electrical energy to the satellite station. Furthermore, the data to be transmitted from the satellite station to the central station is superimposed on the existing static current of the satellite station in the form of current pulses.

  However, a disadvantage of such prior art is that data is only indirectly transmitted from the satellite station to the control device. In addition, each satellite station requires a unique wire-connected interface.

German Patent No. 198559178

  Starting from such prior art, the object of the present invention is to operate a plurality of sensors or satellite stations by means of individual line connections at the control equipment.

によってあらわされる、ことを特徴とする、少なくとも１つの測定量を検出するように構成されている装置によって解決される。さらに上述の課題は、少なくとも１つのセンサを用いた測定量の検出方法であって、当該センサは、測定量を転送するためのデータバス（６）と接続されており、当該センサに、内部抵抗Ｒ_ｉを有する供給電流源（１）を用いて、供給電流Ｉ_Ｂｕｓを前記データバスを介して供給し、ここで前記測定量の検出を、前記データバス（６）上の設定可能な信号形状を有する問い合わせ信号によってトリガする形式の方法において、抵抗Ｒ_２と電流ドレイン（９）から成る直列回路を設けることによって前記供給電流源（１）の電圧を定め、前記直列回路をデータバス（６）に対して並列に配置し、前記電流ドレイン（９）を介して電流Ｉ_Ｂを排出し、当該電流は

によってあらわされる、ことを特徴とする、少なくとも１つのセンサを用いた測定量の検出方法によって解決される。さらに上述の課題は、プログラムコードを有するコンピュータプログラムであって、機械読み出し可能な担体上に格納されており、コンピュータ上で当該コンピュータプログラムが実施される場合に、上述の方法を実施する、ことを特徴とする、プログラムコードを有するコンピュータプログラムによって解決される。さらに上述の課題は、上述の装置を有する集積回路によって解決される。 The above-described problem is a device configured to detect at least one measured quantity, which is supplied with at least one data bus (6), which detects the measured quantity can be connected at least one sensor (5) for, where the said sensor (5), via said data bus (6) supply, the supply current source with an internal resistance R _i by (1) In the type comprising a device (2, 3) to which an electric current _IBUS is supplied and the device can form an inquiry signal having a configurable signal shape on the data bus (6) device, the device for detecting the voltage of the supply current source (1) (R1,12, R2,9,7) has a series circuit consisting of wherein the resistance _{R 2} and the current drain (9) Provided Are, wherein said series circuit is arranged in parallel to the data bus (6), wherein the current drain (9) is provided so as to discharge current I _B, the current

This is solved by a device configured to detect at least one measurement quantity, characterized in that Furthermore, the above-described problem is a method of detecting a measurement amount using at least one sensor, and the sensor is connected to a data bus (6) for transferring the measurement amount, and the internal resistance is connected to the sensor. Supply current I _Bus is supplied via the data bus using a supply current source (1) having R _i , where the measurement quantity is detected by a configurable signal shape on the data bus (6). in the form of a method for triggering the interrogation signal having a determined voltage of the supply current source (1) by providing a series circuit consisting of the resistor R ₂ and the current drain (9), the series circuit data bus (6) arranged in parallel with respect to the discharge current I _B through the current drain (9), the current

It is solved by a method for detecting a measured quantity using at least one sensor, characterized in that Further, the above-described problem is a computer program having a program code, which is stored on a machine-readable carrier, and that the above-described method is performed when the computer program is executed on a computer. This is solved by a computer program having a program code. Furthermore, the above problem is solved by an integrated circuit having the above described device.

1 is a block circuit diagram of one embodiment of a circuit according to the present invention. Desired voltage course characteristics of inquiry signal Time course characteristics of the interrogation signal when the discharge current drain is switched off early Signal course characteristics of the interrogation signal when the discharge current drain is later isolated

によってあらわされる。 The aforementioned problems are solved according to the invention by a device that is configured to detect at least one measurand. Here, at least one data bus is provided by this device. This data bus is connected to at least one sensor for detecting a measured quantity. Here, the supply current I _Bus can be supplied to the sensor by a supply current source having an internal resistance R _i via a data bus. This device includes a device for generating an inquiry signal having a predetermined signal shape on a data bus. Wherein the apparatus has a device for detecting the voltage of the supply current source, and the series circuit is provided consisting of wherein the resistor R ₂ and the current drain (Stromsenke). Wherein the series circuit is arranged in parallel to the data bus, the current drain is provided so as to discharge current I _B. This current _{I B} is

It is expressed by.

によってあらわされる。 Furthermore, a solution to this problem is a method for detecting a measurement amount using at least one sensor. Here, this sensor is connected to a data bus for transferring a measured quantity, and this sensor is supplied with a supply current I _Bus via a data bus using a supply current source having an internal resistance R _i. Is done. Here, the detection of the measurement amount is triggered by an inquiry signal having a predetermined signal shape on the data bus. Here, the voltage of the supply current source is determined. Series circuit is provided including a resistor R ₂ and the current drain here. Wherein the series circuit is arranged in parallel to the data bus, the current I _B is discharged through the current drain. This current _{I B} is

It is expressed by.

  The device according to the invention is, for example, an engine control device for an internal combustion engine in a vehicle. Alternatively or additionally, the device controls the safety function. This is, for example, a trigger for a seat belt pretensioner by means of an air bag device or pyrotechnics. In another embodiment of the invention, this device is responsible for the comfort function. This is, for example, drive control of an electrical power window, sliding roof or auxiliary heater.

  At least one sensor is provided for detecting the measured quantity. This is, for example, a temperature sensor, a pressure sensor, an acceleration sensor, a yaw rate sensor, or the like. This sensor is equipped with an electronic circuit. The electronic circuit processes the sensor data and transforms the sensor data into a form suitable for data transmission via the data bus.

  For this purpose, the electronic circuit includes, for example, an A / D converter, a comparator, a memory, a microcontroller, a microprocessor, and the like. This electronic circuit is monolithically integrated with the sensor member on the semiconductor substrate. Alternatively, the electronic circuit can be configured separately from the sensor. In this case, the electronic circuit and the sensor member are connected to each other on the circuit carrier. This is done, for example, with a conductor plate or a bonding wire. In addition, this circuit performs another function. This is, for example, data validation or sensor self-test.

The proposed device provides a data bus. The data bus has at least two electrical conductors. Here, the electric conductor may be constituted by a vehicle body metal plate. The electrical conductor is used on the one hand to power the sensor and supplies electrical energy to the electronic circuit to which it belongs. Therefore, a static current _IBUS flows on the data bus after the start of operation of the device. This depends on the number and type of sensors used.

  Data transmission from the sensor to the device according to the invention is initiated by an inquiry signal. This inquiry signal is output by the device set for this purpose on the data bus. The interrogation signal may have an encoding. Here, by this encoding, a subgroup of sensors is selected from all the sensors connected to the bus.

  For example, the inquiry signal includes a rectangular pulse. This rectangular pulse is received by the sensor. The sensor is triggered, for example, by the rising or falling edge of a rectangular pulse. This therefore outputs the generated data on the data bus. Here, each sensor is assigned a time window after receiving a rectangular pulse. Within this time window, the sensor transmits data. In this way, various sensor data are prevented from being superimposed.

  The capacity of the data bus varies depending on the number of sensors connected to the data bus, and the static current of the data bus varies depending on the number of sensors. Varies under the current intensity. Therefore, the present invention proposes that the bus capacitance is determined and discharged through the discharge current drain in order to generate the falling edge. Furthermore, to avoid voltage collapse at the sensor, it is necessary to switch off the discharge current drain in a timely manner when the output voltage of the supply current source is reduced to a value just before the rectangular signal is generated. is there.

  In a development of the invention, the voltage amplitude of the rectangular pulse should also be ensured within a predetermined tolerance. Here, the voltage amplitude of the rectangular pulse is determined by the voltage difference between the output voltage of the supply current source immediately before the rectangular pulse is generated and the maximum voltage of the rectangular pulse.

In the present invention to measure the voltage of the supply current source before generating a rectangular pulse, it proposes the use of a series circuit consisting of the resistor R ₂ and the current drain. Here, the series circuit is arranged in parallel to the data bus. Resistance R ₂ of the series circuit in this case, higher by a predetermined factor than the internal resistance R _I of the supply current source. Where the internal resistance R _I, constituted by the resistance of the at least one transistor. This transistor is used for closed loop control of the supply current. Furthermore, the measuring resistance R ₁ is classified as an internal resistance R _I. This is arranged in the data bus to measure the supply current and / or to detect the data stream.

Here, the current drain is controlled in a closed loop as follows. That current I _B is a closed loop control so as to discharge through a current drain. Wherein the current is the same as factors resistance R ₂ exceeds the internal resistance R _I of the supply current source, lower by a factor sentence configurable. Thus, the voltage is set via the current drain. This corresponds to the voltage of the supply current source within the frame of measurement accuracy.

  Here, the voltage through the current drain is used as a reference voltage. This closes the discharge current drain at the appropriate time and avoids downward oscillations in the sensor supply voltage. Alternatively or additionally, the voltage is used as a reference for the amplitude of the rectangular pulse via the current drain. In the embodiment of the present invention, for this purpose, an additional reference voltage is added to the voltage via the current drain.

  In order to control the current drain in a closed loop, it is supplied with the measured supply current of the supply current source. This occurs as a digital measurement or an analog measurement. This adjustment of the current drain at the desired part of the supply current is made, for example, via a PI regulator or a PID regulator. Of course, however, other closed-loop control concepts are known to those skilled in the art and can be used for the purposes of the present invention.

  The device of the present invention exists in the form of an integrated circuit in one embodiment of the present invention. The integrated circuit here includes, for example, electrical resistors, capacitors, transistors and diodes. These work together to realize the functions proposed in the present invention.

  In another embodiment of the present invention, the apparatus of the present invention comprises a microprocessor or microcontroller, on which at least one function of the proposed circuit is at least partly in software form. Consists of The software is here configured such that each function is implemented by a microprocessor or microcontroller. EPROM memory or flash memory is particularly suitable for storing software. However, it will be appreciated that other computer readable storage media are known to those skilled in the art and can be used for the purposes of the present invention.

  In the following, the present invention will be described in more detail with reference to the drawings. However, the general inventive idea is not limited thereby.

  FIG. 1 shows a block circuit diagram of a device according to the invention. This device has a supply current source 1. An operating voltage is supplied to the supply current source 1 via the connection terminal 13. This operating voltage is, for example, a vehicle-mounted power supply network. Therefore, the operating voltage 13 varies depending on the operation state of the vehicle at that time. In another embodiment of the invention, the operating voltage 13 may be supplied by an open network part of the current network or a transformer.

  Further, the data current 6 is connected to the supply current source 1. The data bus 6 here includes at least two electrical conductors. In some cases, one conductor is constituted by a vehicle body metal plate.

  At least one sensor 5 is connected to the data bus 6. In some cases, multiple sensors are provided. This is, for example, 2 to 20. The number of sensors 5 is here different in different vehicles from different manufacturers or in different construction variations of the same vehicle.

  Each of the sensors 5 includes a sensor member for detecting a measurement amount, and the measurement amount is, for example, temperature, acceleration, yaw rate, rotation angle, speed, and the like. In addition, each sensor 5 includes an evaluation circuit. This includes, for example, an A / D converter. In addition, structural groups are built into the sensor 5 for sensor self-testing, data validation, calibration, data area or further functional reduction. Each sensor detects a static current 5 necessary for its operation. Further, each sensor has an electric capacity like the bus line of the data bus 6. This parasitic capacitance is represented by a capacitor 16 in FIG.

  The sensor 5 is configured to receive an inquiry signal. After receiving the inquiry signal, the sensor supplies data to the supply current source 1 via the data bus 6. This data here includes, for example, an initialization signal, an error signal or a measured value. Here, this data is superimposed on the existing static current in the form of current pulses. In order to avoid the superimposition of different data from different sensors, each sensor is fixed to obtain a time window. Within this time window, the sensor sends its own data after receiving the inquiry signal.

In the supply current source 1, an electrical resistance R ₁ is located in the data bus 6. The voltage drops due to this electrical resistance. This voltage is proportional to the static current I _Bus on the bus 6. The voltage drops in the further resistor R _1. This is modulated depending on the current pulse output from the sensor 5. The voltage falling at the resistor R ₁ is measured by the measuring device 11. Here, the measuring device 11 is used to measure the voltage component at the resistor R ₁ that exceeds or falls below the modulated signal component, that is, the voltage component derived from the static current I _BUS . Such a component of the signal voltage is transferred from the measuring device 11 as a data signal Data_out to the subsequent circuit portion. Subsequent circuitry includes, for example, a microprocessor, microcontroller, memory, digital signal processor or actuator. Thus, depending on the measurement signal of the sensor 5, the function of the vehicle or the vehicle internal combustion engine is implemented.

Measuring device 11 so that it can be determined reliably component is below or exceeds the static current I _BUS, components of the static current I _BUS is determined by another measurement device 12. This static current component I _BUS is supplied to specify a trigger threshold value in the measuring device 11. Further, the static current I _BUS measured by the measuring device 12 is used to adjust the static current I _BUS to a settable target value. As the measuring device 11 and / or 12, for example, a comparator or an operational amplifier is used.

The static current I _BUS is set depending on the current acceptance and supply voltage of the sensor. In another embodiment of the present invention, the target value of the static current I _BUS is set depending on the number and type of sensors 5 connected to the data bus 6 and adjusted by the adjusting device 17. The adjusting device 17 here includes, for example, a PI adjuster or a PID adjuster. The adjusting device 17 is realized as hardware or software. In the latter case, a microcontroller or a microprocessor can be used, and the software of the adjusting device 17 is implemented on this microcontroller or microprocessor. In order to influence the actual value, a variable resistance member is provided. This is, for example, a field effect transistor 10. This affects the current supplied from the supply current source 1 to the bus line 6 as follows. That is, the desired current value of the supply current _IBUS is set.

  In order to generate an inquiry signal on the data bus 6, a current source 2 and a current drain 3 are used. The current source 2 is here connected to a higher potential 15. This is higher than the supply voltage set on the bus line 6 based on the supply current.

  The current drain 3 is connected to a lower potential, for example a ground potential.

  The inquiry signal may be, for example, a rectangular pulse, a sine wave signal, a triangular signal, or a sawtooth signal. Hereinafter, generation of a rectangular pulse as an inquiry signal will be described as an exemplary example.

  In order to generate a positive rectangular signal on the supply voltage of the supply current source 1, the first current source 2 connects the bus line 6 to a potential higher than the potential of the current source 1. As a result, current flows from the current source 2 into the bus line 6. This current charges the bus capacitor 16 and makes it a higher potential. In this way, a rising edge of the rectangular pulse is generated.

  After a predetermined duration corresponding to the length of the rectangular pulse, the current source 2 having a higher potential 15 is separated from the bus line 6. The capacitance 16 of the bus line 6 now discharges the sensor 5 via the leakage current and the current load until it again has the potential of the supply current source 1. However, the falling edge generated in this way does not have a certain edge steepness. Rather, the edge steepness varies depending on the capacity of the bus line 6 and the current demand of the sensor 5. In order to compensate for the difference between the predetermined edge steepness and the shape of the falling edge, a current drain 3 is provided. The current drain 3 is connected to a low potential, for example a ground potential.

  The current flowing out through the current drain 3 is selected as follows. That is, the capacitance 16 of the bus line 6 is selected so as to be discharged from a higher potential to the original potential within a predetermined time, that is, with a predetermined edge steepness.

In order to avoid voltage collapse at the sensor, it is necessary to isolate the current drain 3 from the bus line 6 when the voltage of the supply current source 1 is reached. In order to ensure a predetermined maximum amplitude of the rectangular pulse via the voltage of the supply current source 1, the current source 2 must be separated from the bus line 6 when the predetermined maximum amplitude is reached. For this purpose, it is necessary to measure the voltage on the data bus 6 which is set based on the adjustment of the supply current _IBUS by the adjustment device 17 of the current supply source 1.

The resistor R ₂ and the current drain 9 is used. Resistor R ₂ in this case, a predetermined factor greater than the internal resistance of the supply current source 1. The internal resistance of the supply current source 1 is here formed in particular by the magnitude of the measuring resistor R ₁ and the switch-on resistance of the adjusting element 10, ie the source-drain resistance of the field-effect transistor 10 used. In an advantageous embodiment of the invention, the electrical resistance of the resistor R ₂ is about 10 to 100 times the internal resistance of the supply current source 1.

Current is discharged through the resistor R ₂ is controlled by an adjustable current drain 9. In order to ensure open-loop control and / or closed-loop control of the current drain 9 depending on the supply current flowing on the bus line 6, a measured value of the actual value of the supply current is determined via the comparator 12 and the current drain 9 Is supplied via the line 18. Therefore, even when the supply current on the bus line 6 changes, the current flowing through the current drain 9 is always matched. Thus, the current flowing through the current drain 9 corresponds to a settable portion of the supply current of the sensor 5 in the bus line 6. Such a part corresponds to the reciprocal of the factor. By this factor, the resistance R ₂ is larger than the internal resistance R _i of the current source 1. Therefore, current I _B flowing in current drain 9 is equal to the static current I _BUS on the data bus 6, is multiplied by the ratio of the resistance.

In the present invention, in this case, it is known that the following voltage drops through the current drain 9. That is, the voltage set on the data bus 6 when the supply current _IBUS from the supply current source 1 flows.

  In order to prevent or reduce the modulation of the current through the current drain 9 by the data signal, the following is proposed in the development of the invention. That is, it is proposed to scan the static current flowing through the comparator 12 with a time constant. This time constant is greater than the symbolic duration of the data signal on the data bus 6.

  The comparator or regulator 7 is used here to interrupt the connection of the current drain 3 to the bus line 6 when the voltage difference between the line 14 and the data bus 6 reaches a predetermined value, for example 0. In this way, the bus capacity 16 of the data bus 6 is discharged via the current drain 3 until the supply voltage of the sensor 5 drops below the allowable value. In order to take into account the switching time of the current drain 3, in a development of the invention, a signal for separating the connection of the current drain 3 may be triggered by the comparator 7 already when the potential is different from zero. In this case, the bus capacitance is further discharged during the switching delay and then reaches the set target value when the switching member between the bus line 6 and the current drain 3 is opened.

As an alternative or in addition, the potential of the line 14 is raised by the reference voltage source 8 and this potential is supplied to the comparator 4. In such a case, the comparator 4 is used to disconnect the current source 2 from the bus line 6 when the bus line 6 has a potential corresponding to the sum of the supply voltage and the voltage of the reference voltage source 8. Is done. In this way, the maximum amplitude of the inquiry signal is monitored by the reference voltage source 8. Of course, in order to compensate for the switching time of the comparator 4, a signal is triggered to open the line connection between the data bus 6 and the current source 2. This is represented in the context of the comparator 7.
The data exchange between the comparator 12 and the current drain 9, and the data exchange between the comparator 7 and the current drain 3 and the data exchange between the comparator 4 and the current drain 2 are performed digitally according to the embodiment of the present invention. This is done as a data stream or an analog adjustment signal.

FIG. 2 shows the time course of the rectangular signal. This was generated by the apparatus of the present invention shown in FIG. The voltage _VBUS on the data bus 6 with respect to time t is shown.

In FIG. 2, the voltage set based on the static current has the value V ₀ . The supply current source 1 outputs this to feed the sensor 5 on the data bus 6. At time t ₁ , the current source 2 is connected to the bus line 6. As a result, the bus capacitor 16 is charged to a higher potential.

Once t _2, bus capacitance reaches a desired voltage level. This consists of the sum of the supply voltage V 0 and the reference voltage VA of the reference voltage source 8. When such a potential is reached, the current source 2 is adjusted by the comparator 4 as follows. That is, the potential of the bus line 6 is adjusted so as to be maintained at a desired level. At t _3, the falling edge of the interrogation signal is formed. Thus, the current source 2 at t ₃ is separated from the bus line 6. At the same time, the current drain 3 is connected to the bus line 6. In this way, the bus capacitance 16 of the bus line 6 is discharged via the current drain 3.

Bus capacitance 16 at the time point _{t 4} is discharged to the supply voltage level V0. This is identified by the comparator 7. This is because the voltage difference between the line 14 and the data bus 6 is almost zero. Thus, current drain 3 at the time t ₄ is separated from the bus line 6. The bus line 6 now again has a supply voltage level V0. This is set based on the supply current of the sensor member 5.

FIG. 3 shows signal course characteristics for comparison. This signal course is generated without the intervention of the comparator 7 and without the voltage detection of the present invention by the resistor R ₂ and the current drain 9. First, the bus line 6 is at the potential V0 already described with reference to FIG. Similarly, a rising edge is generated between times t ₁ and t ₂ . Until the time _{t 3,} bus capacitance 16 remains in the desired potential. In order to discharge the bus capacitance, the current drain 3 is connected to the bus line 6 for a predetermined time period between t ₃ and t ₄ . This time period is now chosen empirically so that it is sufficient to discharge the bus capacitance up to the voltage level V0.

However, as can be seen from FIG. 3, the discharge time between times t ₃ and t ₄ is not sufficient in this case. This is because, for example, the bus capacity is larger than originally assumed. However, due to fluctuations in supply current and supply voltage V0, the situation shown in FIG. That is, the supply voltage V0 occurs by lower than what was assumed at the time t _4. Finally, the cause of the signal curve shown in FIG. 3 is that the current demand of the sensor 5 or the discharge current of the current drain 3 is lower than originally assumed.

In this case, the bus charges, after disruption of the current drain 3 from the bus line 6 at the time t _4, remaining in an undesirably high potential. This is subsequently discharged by leakage current and current acceptance by the sensor 5. It was not until time t _5, the bus line is set to a desired potential.

FIG. 4 shows another signal shape. This is in conformity with the prior art, and is formed without using the comparator 7. In this case also, the generation of the rectangular pulse until the time t ₃ extends as described in connection with FIGS. Current drain 3 at the time point t ₃ during the predetermined duration, is connected to the bus line 6.

However, as shown in FIG. 4, t ₃ and t discharging time between ₄ is selected too long. For example, this is related to the following. That is, the bus capacity 16 is related to being smaller than originally assumed, or the supply voltage level V0 being larger than originally assumed. Further, the cause of the signal course characteristic shown in FIG. 4 may be that the current demand of the sensor 5 or the discharge current of the current drain 3 is larger than originally assumed. Bus capacitance 16 in this case, until the time t _4, is discharged below the potential V0. As a result, the supply voltage of the sensor 5 collapses and an error occurs in the function of the sensor. Only after the time t _4, when the current drain 3 are separated from the bus line 6, the supply current source 1, a bus line 6 again, to charge to a desired voltage level. Thus the rectangular pulse generated before the voltage level V0, the first time is reached at time t _5.

  Of course, those skilled in the art will appreciate that the present invention is not limited to the embodiments shown. Rather, upon conversion of the invention, modifications and changes can be made without substantially changing the invention itself. Accordingly, the specification is not to be construed as limiting the invention, but as an illustration of the invention.

Claims (11)

An apparatus configured to detect at least one measurand, comprising:
At least one data bus (6) is provided by the device,
The data bus can be connected to at least one sensor (5) for detecting the measured quantity, wherein the sensor (5) is connected to the internal resistance R _i via the data bus (6). A supply current I _BUS is supplied by a supply current source (1) comprising
Said device comprises a device (2, 3) capable of forming an interrogation signal having a configurable signal shape on said data bus (6);
The apparatus, the apparatus for detecting the voltage of the supply current source (1) (R1,12, R2,9,7) has a series consisting of wherein the resistance _{R 2} and the current drain (9) A circuit is provided,
Here, the series circuit is arranged in parallel to the data bus (6),
The current drain (9) is provided so as to discharge current I _B, the current

Represented by the
A device configured to detect at least one measurand. At least one comparator (4, 7) is provided, whereby the potential difference between the terminal (14) of the current drain (9) and the conductor of the data bus (6) is measured,
2. The device according to claim 1, wherein the device (2, 3) for forming the interrogation signal is open-loop controlled and / or closed-loop controlled depending on the output of the comparator (4, 7).   Device according to claim 2, wherein a reference voltage source (8) is arranged between the terminal (14) of the current drain (9) and the input side of the comparator (4). A resistor (R ₁ ) is provided, the resistor is connected in series with the conductor of the data bus (6), and the voltage dropped through the resistor (R ₁ ) when the supply current source (1) is operated is 4. The device as claimed in claim 1, wherein the device is provided for at least the closed-loop control of the current drain (9). An A / D converter (12) is provided, the A / D converter digitizes the voltage dropped through the resistor (R ₁ ),
The device according to claim 4, wherein the current drain is configured to receive a target value setting digitally. A method for detecting a measurand using at least one sensor,
The sensor is connected to a data bus (6) for transferring a measured quantity, and a supply current source (1) having an internal resistance R _i is used for the sensor to supply the supply current I _Bus to the data bus. Supply through
Wherein the detection of the measured quantity is triggered by an inquiry signal having a configurable signal shape on the data bus (6),
It determines the voltage of the supply current source (1) by providing a series circuit consisting of the resistor R ₂ and the current drain (9),
Wherein placing a series circuit in parallel to the data bus (6), to discharge the current I _B through the current drain (9), the current

Represented by the
A method for detecting a measurement amount using at least one sensor. Measuring the potential difference between the terminal (14) of the current drain (9) and the conductor of the data bus (6) by means of at least one comparator (4, 7);
Method according to claim 6, wherein the device (2, 3) for forming the interrogation signal is open-loop controlled and / or closed-loop controlled depending on the output of the comparator (4, 7).   Method according to claim 7, wherein a reference voltage (8) is applied between the terminal (14) of the current drain (9) and the input side of the comparator (7). In order to measure the supply current I _BUS , the voltage drop across the resistor (R ₁ ) is identified;
The resistor is connected in series with the conductor of the data bus (6),
The method according to claim 8, wherein the voltage drop is used at least for closed-loop control of the current drain (9). A computer program having program code,
Stored on a machine-readable carrier,
When the computer program is executed on a computer, the method according to any one of claims 6 to 9 is performed.
A computer program having a program code.   An integrated circuit comprising the device according to claim 1.

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