阅读说明：本技术 用于发送和接收转速信息的设备和方法 (Apparatus and method for transmitting and receiving rotational speed information ) 是由 S·丰塔内西 P·洛尔贝 T·沃斯 于 2019-08-19 设计创作，主要内容包括：本公开的内容涉及一种用于发送和接收转速信息的设备和方法、计算机程序和数据载体。在此提供了用于发送和接收转速信息的设备和方法以及相应的计算机程序和电子可读数据载体。在此,借助于电流接口传送脉冲序列,该脉冲序列对多个位进行编码。多个位中的第一位组用于指示脉冲序列是否已经在磁场的过零处被发送。根据第一位组来选择被调制到多个位中的第二位组上的信息。(The present disclosure relates to a device and a method for transmitting and receiving rotational speed information, a computer program and a data carrier. Devices and methods for transmitting and receiving rotational speed information, as well as corresponding computer programs and electronically readable data carriers are provided. In this case, a pulse sequence is transmitted by means of the current interface, which pulse sequence encodes a plurality of bits. A first group of bits of the plurality of bits is used to indicate whether the pulse sequence has been transmitted at a zero-crossing of the magnetic field. Information modulated onto a second group of bits of the plurality of bits is selected according to the first group of bits.)

1. A device (13; 20) for transmitting rotational speed information, comprising:

signal processing means (25) for receiving the magnetic field sensor signal, an

A current interface (26) for transmitting a sequence of pulses of a current signal, wherein each sequence of pulses comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level,

wherein the signal processing device (25) is provided for detecting, on the basis of the magnetic field sensor signal, a zero crossing of an extension curve of a magnetic field and a further point of the extension curve of the magnetic field and for controlling the current interface to transmit a pulse sequence upon detection of a zero crossing or a further point of the magnetic field,

wherein a first group of bits of the plurality of bits of a respective pulse sequence is marked with: is related to the pulse sequence transmitted upon detection of a zero-crossing or is related to the pulse sequence transmitted upon detection of a further point and selects the information modulated onto the second group of bits of the plurality of bits of the respective pulse sequence in dependence on being related to the pulse sequence transmitted upon detection of a zero-crossing or upon detection of a further point.

2. The device (13; 20) according to claim 1, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits specifying: whether it concerns a pulse sequence transmitted when a zero crossing is detected.

3. The device (13; 20) of claim 2, wherein the second group of bits comprises a sixth bit, a seventh bit and an eighth bit of the plurality of bits.

4. Device (13; 20) according to any one of claims 1 to 3, wherein the further point of the magnetic field corresponds to a crossing point (41, 42) through a threshold value of the magnetic field, a global minimum of the magnetic field and/or a global maximum of the magnetic field.

5. Device (13; 20) according to any one of claims 1 to 4, wherein phase information is modulated onto the second group of bits if it relates to a pulse sequence transmitted when a further point is detected, the phase information indicating: the pulse sequence is transmitted upon which further point of the magnetic field is detected.

6. Device (13; 20) according to any one of claims 1 to 5, wherein information indicating the strength of the magnetic field is modulated onto the second bit group if it relates to a pulse sequence transmitted at one zero crossing.

7. Device (13; 20) according to any one of claims 1 to 4, wherein the first group of bits furthermore marks whether an error has occurred.

8. The device (13; 20) according to claim 7,

if a pulse sequence transmitted at a zero crossing is involved and no error occurs, information indicating the strength of the magnetic field is modulated onto the second bit group, and

if no errors occur, relate to the pulse sequence transmitted at a further point of the magnetic field and no errors occur, phase information indicating at which point of the magnetic field the pulse sequence is transmitted is modulated onto the second bit group.

9. Device (13; 20) according to claim 7 or 8, wherein an error code is modulated onto the second bit group as information if an error occurs and relates to a pulse sequence transmitted at a zero crossing, and the phase information is modulated onto the second bit group if a pulse sequence transmitted at a further point of the magnetic field is referred to.

10. Device (13; 20) according to claim 8, wherein an error code is modulated onto the second group of bits as information if there is an error.

11. A device (14; 21) for receiving rotational speed information, comprising:

a current interface (27) for receiving a sequence of pulses of a current signal, wherein each sequence of pulses comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, and

signal processing means (28) for processing the received pulse sequence, wherein the signal processing means are arranged for determining the type of information modulated onto a second group of bits of the plurality of bits from a first group of bits of the plurality of bits of the respective pulse sequence, wherein in the first group of bits: is a pulse sequence transmitted when a zero crossing of the extension curve of the magnetic field is detected or is a pulse sequence transmitted when a further point of the extension curve of the magnetic field is detected.

12. Device (14; 21) according to claim 11, wherein the signal processing means (28) are arranged for processing a pulse sequence transmitted by the device according to any one of claims 1 to 10.

13. A method for transmitting rotational speed information, comprising:

the zero crossings and further points of the extension curve of the magnetic field are detected,

transmitting respective pulse sequences upon detection of the zero crossing and the further point of the magnetic field, wherein each pulse sequence comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, and

wherein marked in a first group of bits of the plurality of bits of a respective pulse sequence are: is related to the pulse sequence transmitted when a zero crossing is detected or is related to the pulse sequence transmitted when a further point is detected and the information modulated onto the second group of bits of the plurality of bits is selected in dependence on the pulse sequence transmitted when a zero crossing is detected or the pulse sequence transmitted when a further point is detected.

14. The method of claim 13, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits specifying: whether it concerns a pulse sequence transmitted when a zero crossing is detected.

15. The method of claim 14, wherein the second group of bits includes a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

16. Method according to any of claims 13 to 15, wherein the further point of the magnetic field corresponds to a crossing point (41) through a threshold value of the magnetic field, a global minimum of the magnetic field and/or a global maximum of the magnetic field.

17. The method of any of claims 13 to 16, wherein phase information is modulated onto the second group of bits if not related to a pulse sequence transmitted when a further point is detected, the phase information indicating: at which further point of the magnetic field the pulse sequence is transmitted.

18. The method according to any of claims 13 to 17, wherein information indicating the strength of the magnetic field is modulated onto the second bit group if it relates to a pulse sequence transmitted at one zero crossing.

19. The method according to any of claims 13 to 18, wherein the first group of bits further flags whether an error occurred.

20. The method of claim 19, wherein,

if a pulse sequence transmitted at a zero crossing is involved and no error occurs, information indicating the strength of the magnetic field is modulated onto the second bit group, and

if no errors occur and a pulse sequence is transmitted at a further point of the magnetic field, phase information indicating at which detected point of the magnetic field the pulse sequence was transmitted is modulated onto the second bit group.

21. The method according to claim 19 or 20, wherein an error code is modulated onto said second bit group as information if there is an error and relating to a pulse sequence transmitted at a zero crossing, and said phase information is modulated onto said second bit group if relating to a pulse sequence transmitted at a further point of said magnetic field.

22. The method of claim 19 or 20, wherein an error code is modulated onto the second group of bits as information if there is an error.

23. A method for receiving rotational speed information, comprising:

receiving pulse sequences, wherein each pulse sequence comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, wherein a first bit group of the plurality of bits of the respective pulse sequence specifies: is related to the pulse sequence transmitted when a zero crossing of the magnetic field is detected, or is related to the pulse sequence transmitted when a further value of the magnetic field is detected,

determining, based on the first group of bits, a type of information to be modulated onto a second group of bits of the plurality of bits of the corresponding pulse sequence, an

Evaluating the information modulated onto the second group of bits according to the determined type of the information.

24. The method of claim 23, wherein the method is arranged for processing a pulse sequence transmitted by a method according to any one of claims 13 to 22.

25. A computer program having a program code which, when inserted on a processor, causes the method of any of claims 13 to 24 to be performed.

26. An electronically readable tangible data carrier having a computer program according to claim 25.

Technical Field

The present application relates to a device and a method for transmitting and receiving rotational speed information, and to a corresponding computer program and data carrier.

Background

In vehicle technology, for example in the manufacture of motor vehicles, sensors are used to determine the rotational speed of a vehicle tire. These rotational speeds are then used in some cases for safety-relevant systems, such as anti-lock brake systems, or for controlling other components of the vehicle drive train. The information on the rotational speed of the wheel is usually determined by means of a magnetic signal generator which is connected to the wheel in a rotationally fixed manner and a stationary magnetic field sensor which detects the magnetic field generated by the signal generator. The signal generator may be, for example, a ferromagnetic gear or a magnetic pole rotor having a plurality of magnetic elements, for example permanent magnets, which are distributed uniformly over its circumference and have an alternating magnetic orientation. When the signal generator rotates with the wheel, the generated magnetic field changes, and these changes are measured by the magnetic field sensor. Such a magnetic field sensor may have one or more individual sensor elements.

Information is then generated from the measured magnetic field, which information is transmitted to the control unit of the vehicle. For this purpose, the so-called AK protocol is used in many cases. Conventionally, in the case of the AK protocol, a pulse, also referred to as a speed pulse, is generated at each zero crossing of the magnetic field acquired by the magnetic field sensor. Following the pulse, other information may be transmitted, such as error information, information on the size of the air gap between the sensor and the signal generator, rotation direction information, etc.

In particular in low-speed situations, such as occur during a parking maneuver, the distance between zero crossings can be relatively large. Due to the large distance, the vehicle position may not be determined with sufficient accuracy for the parking process, depending on the rotational speed. Therefore, higher resolution of the rotational speed information would be desirable in such a case.

In principle, such a higher resolution can be achieved by detecting not only the zero crossing but also other points of the magnetic field and using them to output information to the control unit. However, with current implementations of the AK protocol, it may be difficult to transmit such higher resolution information, where other information, such as error information or information in terms of magnetic field strength, should be transmitted as always as possible.

Disclosure of Invention

A method according to the invention is provided herein. The following defines further embodiments as well as a computer program and a corresponding data carrier.

According to one embodiment, there is provided an apparatus for transmitting rotational speed information, including:

signal processing means for receiving the magnetic field sensor signal, an

A current interface for transmitting a sequence of pulses of a current signal, wherein each sequence of pulses comprises a first pulse having a first current level followed by a plurality of bit pulses, a bit pulse encoding a plurality of bits at a second current level and a third current level,

wherein the signal processing device is provided for detecting zero crossings of the magnetic field extension curve and further points of the magnetic field extension curve on the basis of the magnetic field sensor signal and, upon detection of a zero crossing or a further point of the magnetic field, for actuating the current interface to transmit a pulse sequence, wherein in a first group of bits of a plurality of bits of the respective pulse sequence: is related to the pulse sequence transmitted upon detection of a zero crossing or is related to the pulse sequence transmitted upon detection of a further point, and the information modulated onto the second group of bits of the plurality of bits of the respective pulse sequence is selected in dependence on the pulse sequence transmitted upon detection of a zero crossing or the pulse sequence transmitted upon detection of a further point.

According to another embodiment, there is provided an apparatus for receiving rotation speed information, including:

a current interface for receiving a pulse train of a current signal, wherein each pulse train comprises a first pulse having a first current level followed by a plurality of bit pulses, a bit pulse encoding a plurality of bits at a second current level and a third current level, and

signal processing means for processing the received pulse sequence, wherein the signal processing means are arranged for determining, from a first group of bits of the plurality of bits of the respective pulse sequence, a type of information modulated onto a second group of bits of the plurality of bits, and evaluating the second group of bits according to the determined type of information, wherein in the first group of bits: is related to the pulse sequence transmitted when a zero crossing of the magnetic field is detected or is related to the pulse sequence transmitted when a further point of the magnetic field is detected.

According to another embodiment, there is provided a method for transmitting rotational speed information, including:

the zero crossings and further points of the magnetic field are detected,

transmitting respective pulse sequences upon detection of the zero crossing and the further point, wherein each pulse sequence comprises a first pulse having a first current level followed by a plurality of bits, the plurality of bits being encoded with a second current level and a third current level, and

wherein in a first group of bits of the plurality of bits of the respective pulse sequence is marked: to the pulse sequence transmitted when a zero crossing is detected or to the pulse sequence transmitted when a further point is detected and to select the information modulated onto the second group of bits of the plurality of bits in dependence on the pulse sequence transmitted when a zero crossing is detected or when a further point is detected.

According to another embodiment, there is provided a method for receiving rotational speed information, including:

receiving a sequence of pulses, wherein each sequence of pulses comprises a first pulse having a first current level followed by a plurality of bits encoded with a second current level and a third current level pair, wherein a first group of bits of the plurality of bits of the respective sequence of pulses specifies: whether it concerns a pulse sequence transmitted when a zero crossing is detected, or a pulse sequence transmitted when a further value is detected,

determining, based on the first group of bits, a type of information to be modulated onto a second group of bits of a plurality of bits of a corresponding pulse sequence, an

The information modulated onto the second group of bits is evaluated in response to the determined type of information.

The above summary is only a brief summary of some embodiments and should not be construed as limiting.

Drawings

FIG. 1 is a schematic diagram of a system according to one embodiment.

FIG. 2 is a block diagram of a system according to one embodiment.

Fig. 3 shows a pulse sequence used in an embodiment.

Fig. 4 shows providing high resolution rotational speed information based on a measured magnetic field.

Fig. 5 is a flow chart for explaining a method according to an embodiment.

Fig. 6 is a table for explaining a protocol according to an embodiment.

Fig. 7 is a table for explaining a protocol according to another embodiment.

Detailed Description

Hereinafter, various embodiments will be explained in detail. These embodiments are merely illustrative and should not be construed as limiting. Features of the various embodiments may be combined to obtain further embodiments. Variations and modifications described with respect to one embodiment are also applicable to other embodiments, and thus the description will not be repeated.

Although a rotational speed sensor for a motor vehicle, in particular a wheel rotational speed sensor, will be described below as an example, the illustrated embodiment is generally applicable to applications in which information relating to the rotational speed is measured and transmitted to another unit.

In the context of the present application, the term "magnetic field sensor" denotes a device that can detect a magnetic field. Such a magnetic field sensor may comprise a single sensor element or a plurality of sensor elements, wherein each sensor element is used to detect at least one magnetic field component, i.e. a magnetic field in a particular direction or plane, at the location of the respective sensor element. The sensor elements may be hall sensor elements or magneto-resistive sensor elements, also referred to as XMR elements.

In the context of the present application, a sensor device relates to a device comprising a magnetic field sensor and other components for processing a sensor signal and for transmitting information based on the sensor signal.

FIG. 1 illustrates a system according to one embodiment. The system of fig. 1 comprises a pole rotor 11, which is coupled to a rotating shaft 10. The rotating shaft 10 may be, for example, a rotating shaft of a vehicle tire to measure the rotation speed of the vehicle tire. In other embodiments, the rotating shaft 10 may be coupled to other components whose rotational speed is to be measured, for example other automotive components, such as a drive shaft or engine component or also a steering wheel, or components external to an automotive application. Instead of the pole rotor 11, another signal generator, for example a ferromagnetic gear, can also be used, which generates a time-dependent course of the magnetic field during the rotational movement.

According to one embodiment, the sensor device 13 is arranged adjacent to the pole rotor 11. The sensor device 13 includes: a magnetic field sensor having one or more sensor elements to measure the magnetic field generated by the pole rotor 11; and other components to transmit the rotation speed information to the control unit 14(ECU, electronic control unit). The sensor device 13 is provided for sending the rotation speed information according to the embodiment according to a modified AK protocol. This modified AK protocol will be explained in detail later. Accordingly, the control unit 14 is arranged to receive and evaluate information based on the modified AK protocol. Depending on the received information, the control unit 14 may then actuate the controlled device 15. For example, the rotational speed information may be used for controlling braking to implement an anti-lock braking system (ABS).

The sensor device 13 and the control unit 14 may be implemented in any conventional manner known to those skilled in the art, except using a modified AK protocol. The structure of such a sensor device and control unit using such a modified AK protocol will be explained in more detail below with reference to fig. 2.

Fig. 2 shows a sensor device 20 and a control unit 21, which may be an example of the sensor device 13 and the control unit 14 of fig. 1, but which can also be used in embodiments other than the example in fig. 1.

The sensor device 20 comprises a magnetic field sensor 23, which may have one or more sensor elements as described. The output of the magnetic field sensor 23 is supplied to an analog-to-digital converter 24 for analog-to-digital conversion. The sensor output thus digitized is then processed digitally in a signal processing device 25. The signal processing means 25 may be implemented by means of one or more digital signal processors, other correspondingly programmed processors, or by means of dedicated hardware, such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA). In the signal processing 25, for example, zero crossings of the magnetic field detected by the sensor 23 or other specific points of the (time-varying) course of the magnetic field can be detected, the strength of the magnetic field can be acquired, or else a fault monitoring can be performed. A point of the magnetic field or a point in the course of the magnetic field is here a point in time at which the magnetic field has a predetermined property, for example a predetermined value, a (global) minimum or a (global) maximum, or a specific phase angle. This will be explained in more detail below with reference to fig. 4.

The signal processing means 25 then drive the current interface 26 to transmit information via the lines 22A, 22B. Information is encoded according to the current level according to the modified AK protocol according to an embodiment. The current on the lines 22A, 22B can additionally be used to supply the sensor device 20. The sensor device 20 and its components may be implemented in any conventional manner, except using a modified AK protocol described later. In other words, the signal processing means 25 are provided in particular for controlling the current interface 26 to transmit information according to the modified AK protocol, and may otherwise process the information output by the digital sensor in a conventional manner. According to one exemplary embodiment, the signal processing device 25 and the current interface 26 form a device for transmitting rotational speed information.

On the part of the control unit 21, the current interface 27 receives the transmitted information and supplies the transmitted information to the signal processing means 28. In one embodiment, the signal processor 28 interprets information received according to a modified AK protocol. The current interface 27 and the signal processing means 28 may be implemented in any conventional manner, except that a modified AK protocol is used. As with the signal processing means 25, the signal processing means 28 may also be implemented, for example, by means of a digital signal processor, a correspondingly general-purpose programmed processor and/or by means of specific hardware.

In the following, various embodiments of a modified AK protocol that may be used in the systems of fig. 1 and 2 will be explained.

As with conventional AK protocols, the modified AK protocol according to various embodiments also uses a pulse sequence consisting of a speed pulse followed by a plurality of information bits, in particular nine information bits. In some implementations, the information bits are represented as bit pulses b0, b 1. An example of a pulse sequence consisting of a velocity pulse and a bit pulse is shown in fig. 3. The pulse sequence uses three current levels, a high current level IH, a medium current level IM and a low current level IL. For example, IH may be about 28mA, IM about 14mA, and IL about 7 mA. Each pulse train has a velocity pulse 30 with a high current level IH. After the speed pulse 30 (sometimes referred to as sync pulse), the bits b0 to b8 (9) are encoded with the corresponding bit pulses by means of the current levels IM, IL. These bit pulses are only schematically shown in fig. 3. For example, a logic 1 of bits b0 through b8 may be encoded by a transition from IM to IL, and a logic 0 may be encoded by a transition from IM to IL. In other embodiments, a logic 1 may be encoded by current level IM and a logic 0 may be encoded by current level IL. The pulse sequence of fig. 3 corresponds in general to a conventional AK protocol.

In contrast to the conventional AK protocol, the pulse sequence of fig. 3 is not only transmitted at the zero crossing of the magnetic field, but also at other points of the magnetic field in at least one operating mode in order to increase the resolution, since more than two measurement times are available over one period of the time-varying magnetic field. The at least one operating mode may be a low speed operating mode, e.g. the rotational speed is below a predetermined threshold.

In at least one operating mode, it is specified in the bits of the first bit group whether a pulse sequence at the zero crossing or a pulse sequence at another point of the magnetic field is involved. Additionally, in some embodiments, the first group of bits also contains error bits. A bit group in the sense of this application may comprise one or even more bits. Furthermore, in a modified AK protocol according to some embodiments, the values of the bits corresponding to the first bit group, i.e. depending on whether the pulse sequence is sent at zero crossings or at other values, and possibly depending on whether an error occurs, different information is modulated onto the bits of the second bit group. In the pulse sequence generated at the zero crossing of the magnetic field, information indicating the strength of the magnetic field can thus be modulated, for example, onto the bits of the second bit group. The magnetic field strength is related to the air gap between the magnetic field sensor and the signal generator. In a pulse sequence that is transmitted at another point in the magnetic field, phase information may be modulated onto the second group of bits, the phase information indicating at which point in the magnetic field the group of pulses has been transmitted. The information about at which point of the magnetic field the pulse sequence is used is in the context of this application often referred to as phase information, e.g. it may encode a point or encode the phase angle at which the point is located. Additionally, in some embodiments, if the first group of bits has bits indicating an error, in the event of an error, an error code may be modulated onto the second group of bits. An example of this will be explained in more detail later with reference to fig. 6 and 7.

Fig. 4 schematically shows a sinusoidal extension of the measured magnetic field over time for explaining the zero crossings and further points of the magnetic field extension. Such a sinusoidal curve is formed, for example, at least approximately in the case of the sensor device 13, when the pole rotor 11 of fig. 1 rotates. The magnetic field is acquired by a magnetic field sensor, such as sensor 23 of fig. 2, digitized, and processed by signal processing means, such as signal processing means 25. In particular, a zero crossing 40 of the magnetic field is detected. Each time a zero crossing is detected, a sequence of pulses is sent, as shown in fig. 3.

In addition, at least in one operating mode, for example when the rotational speed falls below a predetermined threshold value, further points of the course of the magnetic field are detected and a pulse sequence can be transmitted at these points. For example, if the magnetic field intersects a positive threshold 41 at 43 or 44 in fig. 4 (from low to high magnetic field strength at 43 and high to low magnetic field strength at 44), or a negative threshold 42 at 45 or 46, a pulse sequence is sent. Additionally or alternatively, a global maximum 47 or a global minimum 48 of the magnetic field extension curve may be detected. In other embodiments, a determined phase angle, e.g. 30 °, 60 °, etc., reaching a sinusoidal extension curve is detected.

In some embodiments, additional points may also be detected by using multiple sensor elements. The instantaneous phase angle of the magnetic field is thus determined in a manner known per se from a plurality of sensor signals of sensor elements arranged along the pole rotor, wherein the course of the magnetic field is "seen" offset in time from one another by means of the plurality of sensor elements.

When these detect further points 43 to 48, a pulse sequence as shown in fig. 3 can likewise be transmitted. As already explained with reference to fig. 3, one bit of the first group of bits indicates: whether it concerns a pulse sequence transmitted when a zero crossing 40 is detected or a pulse sequence transmitted when another point 43 to 48 is detected.

In the case of a pulse sequence detected at the zero crossing, an information, for example about the strength of the magnetic field, is modulated on the second group of bits, while in the case of a pulse sequence detected at the other point, a phase information is modulated, the phase information indicating: at which of the further points 43 to 48 the respective pulse sequence has been sent.

For this purpose, for example, a special bit code can be assigned to each point 43 to 48, which bit code is then modulated onto the second group of bits.

As already mentioned, in some embodiments, the first group of bits may additionally include error bits indicating an error. If an error is indicated, an error code may also be modulated onto the second group of bits. This will be explained later with reference to fig. 7.

Fig. 5 shows a flow chart for describing a method according to an embodiment, which uses the above-described working steps. For example, the method may be implemented in the system of fig. 1 or the system of fig. 2, but is not limited thereto. As has likewise already been mentioned, the method can be carried out in particular in an operating mode in which the rotational speed, for example the wheel rotational speed, is below a predetermined threshold value. At higher speeds, communication may then take place in a conventional manner, in particular according to a conventional implementation of the AK protocol. In other embodiments, communication may be performed according to the method of FIG. 5, regardless of rotational speed.

At 50 in fig. 5, the first group of bits of a pulse sequence encoding a plurality of bits (as shown in fig. 3) is marked as relating to a pulse sequence that is transmitted when a zero crossing is detected (i.e., such as at the zero crossing 40 of fig. 4), or as relating to a pulse sequence that is transmitted at another point in the magnetic field (such as at points 43 through 48 of fig. 4).

At 51, information corresponding to the first group of bits is selected and modulated onto the second group of bits. In the case of a pulse sequence transmitted at zero crossing, this information can be, for example, information about the strength of the magnetic field, while in other respects this information can be phase information which marks at which point of the acquired magnetic field a further point is detected at which the pulse sequence is transmitted. Furthermore, if the first bit set indicates an error, an error code may also be sent as information. At 52, a pulse sequence including a first bit group and a second bit group is transmitted.

On the receiver side, e.g. in the control unit of fig. 1 or the control unit 21 of fig. 2, the pulse sequence is then received at 53 and, at 54, the second bit group is evaluated based on the first bit group. In other words, the first group of bits indicates which type of information is contained in the second group of bits and, in response thereto, the second group of bits is interpreted as information, for example in terms of the magnetic field strength, phase information or an error code. The type of information thus indicates what the value encoded in the second bit set indicates, e.g. the magnetic field strength, the phase information or an error code.

With such an embodiment, especially also when using short bit sequences, such as the 9-bit sequence of the pulse sequence of fig. 3, information in terms of phase position is transmitted to increase the resolution, and also regular information, such as information in terms of air gap size and/or error information, error codes, is always transmitted.

Fig. 6 and 7 show in tabular form two embodiments of a modified AK protocol indicating which information is modulated on which bit of the 9-bit sequence of the pulse sequence of fig. 3. The protocols of fig. 6 and 7 describe a modification of the conventional AK protocol, in particular in the case of fig. 6 of the so-called AK-LR protocol, in which one bit of the pulse sequence indicates whether an air gap reserve is reached, where the protocol of fig. 6 is a protocol without error information, while the protocol of fig. 7 is a protocol with error code transmission in the case of errors.

In fig. 6 and 7, the first column (viewed from the left) indicates the number (0 to 8) of these bits, the second column indicates which information is modulated onto the respective bit, the third column indicates the abbreviation of the respective bit, and the fourth column indicates which value is assigned to this bit, in particular in the case of a modified AK protocol, such as discussed in the operating mode with a rotational speed below a threshold value. In other cases, these bits may be occupied as in conventional AK protocols.

In fig. 6, bit 0, i.e. the first bit, indicates whether a so-called air gap reserve is reached, i.e. whether the magnetic field strength is sufficient for a correct measurement. If this air gap reserve is reached, a value of 1 is assigned to bit 0. It should be noted that this and other values are used as examples only, and for example inverse coding (using the value 0 instead of the value 1 and vice versa) is also possible. The occupation of bit 0 selected in fig. 6 corresponds to the conventional use of bit 0.

The following information is modulated onto bit 1 (second bit): whether the pulse sequence relates to a pulse sequence transmitted at a zero crossing (point 40 of fig. 4) or whether the pulse sequence is transmitted at another point (e.g., points 43 to 48 of fig. 4). In the example of fig. 6, if a pulse sequence transmitted at zero crossing is concerned, a value of 1 is assigned to bit 1; and a value 0 is assigned to bit 1 if a pulse sequence is involved which is transmitted at another point in order to increase the resolution. Bit 1 forms the first bit group described above in the embodiment of fig. 6, i.e. it consists of only one bit in this case.

Bit 2 indicates whether there is a low speed, in which case a modified AK protocol is used. In the embodiment of fig. 6, if the frequency f of the zero crossing pulse is zero_encBelow a threshold value f_activationThen the value 1 is assigned to bit 2.

Bit 3 indicates whether the direction of rotation is valid, i.e. correctly identified, and is set to 1 if the direction of rotation is valid. Bit 4 indicates the direction of rotation (0) if the direction of rotation is positive and 1 if the direction of rotation is negative. In some implementations, the direction of rotation may be defined according to the pins of the magnetic field sensor used. For example, a positive rotational direction may be defined as the rotational direction in which the pole rotor 11 of fig. 1 moves from the VDD pin to the ground pin of the sensor when the sensor surface is facing the pole rotor. Other definitions are possible. Bits 3 and 4 correspond to the conventional use of these bits, at least in some conventional AK protocols.

The information modulated onto bits 5 to 7 depends on whether it relates to a pulse sequence transmitted at zero crossing or a pulse sequence transmitted at another point. Thus, in this case, bits 5 to 7 form the second bit group. In the embodiment of fig. 6, if bit 1 is set to 0, i.e. a pulse sequence is sent at another point of the magnetic field, phase information is modulated onto bits 5 to 7, the phase information indicating at which point the pulse sequence is sent (e.g. at which point of 43 to 48 of fig. 4). In this case, the (three) bits 5 to 7 are referred to as a0 to a2 and just encode phase information to improve resolution. For example, a 3-bit value may be allocated to each of the points 43-48 of fig. 4 (e.g., 000 for point 43, 001 for point 47, 010 for point 44, 011 for point 45, 100 for points 48 and 101 for point 46), and if a pulse sequence is transmitted at the corresponding point, the corresponding bit value is modulated onto the bits 5 to 7. In general, up to eight positions can be encoded with (three) positions a0 to a 2. In the example of fig. 4, only six positions are used, and in other embodiments, more or fewer additional points of the transmit pulse sequence may be defined. For example, eight points may be defined by monitoring the crossing of two different positive thresholds instead of only one positive threshold 41, and the crossing of two different negative thresholds instead of negative threshold 42.

In the case of a pulse transmitted at zero crossing (bit 1 ═ 1), information in terms of magnetic field strength, i.e., magnetic field amplitude, is encoded onto bits 5-7 as bits LM0 through LM2, as in some conventional implementations of the AK protocol. Here, a value of 000 may indicate that the sensor is not calibrated, and in other cases the magnetic field strength may be encoded as a value of 001 to 111. As already explained, the magnetic field strength is dependent on the size of the air gap, from which information about the size of the air gap can therefore be derived.

Bit 8 is a parity bit and therefore can be used as a check for the correct transmission pulse sequence. In the example of fig. 6, if parity including a parity bit is an even number, the parity bit is set to 1, and if parity is an odd number, the parity bit is set to 0.

Note that in the AK protocol, bits 1, 5, 6, and 7 are idle available, so the protocol of fig. 6 uses these idle occupiable bits to provide additional functionality, particularly to transmit additional information.

Fig. 7 shows a further exemplary embodiment of a protocol according to the present invention, which additionally may transmit error information. Bits 1 to 4 and 8 of the embodiment of fig. 7 correspond to bits 1 to 4 and 8 of the embodiment of fig. 6 and are therefore not described again.

In the case of fig. 7, bit 0 is an error bit. If there is an error, it is assigned bit value 1; if there are no errors, bit 0 is allocated.

The error can be, for example, an erroneous measured value from the sensor or any other error which is also implemented in conventional sensors by a self-test device or the like. Examples of such errors are a drop in the external supply voltage or the internal supply voltage of the sensor device below a threshold value, a failure or a frequency error of the clock signal, a detected magnetic field strength below a threshold value, saturation of an analog-to-digital converter (e.g. 24 in fig. 2) or of a digital-to-analog converter, overheating or a time above a threshold value during which no minimum or maximum value of the magnetic field extension curve is identified. In some embodiments, the invalid rotational direction may also be an error, but it is processed separately via bit 3 in the embodiment of FIG. 7.

In the embodiment of FIG. 7, bits 0 and 1 form a first group of bits, and bits 5 through 7 again form a second group of bits. In other words, the values of bits 0 and 1 indicate which information is modulated onto bits 5 through 7.

If there is no error (bit 0 ═ 0), then in the embodiment of fig. 7, bits 5 through 7 are occupied as in the embodiment of fig. 6, i.e., if bit 1 ═ 0, with bits a0 through a2 indicating phase information; if bit 1 is then transmitted at zero crossing, the pulse sequence is occupied by bits LM0 to LM2 which indicate information on the magnetic field strength. If an error is present, i.e. bit 1 is 1, in one embodiment, in the case of bit 1 is 1 (pulse sequence at zero crossing), bits 5 to 7 are occupied by a 3-bit error code ERR0 to ERR2 indicating which type of error is present, for example which type of the above-mentioned error. When bit 1 is 0, bits 5 to 7 are always occupied with phase information a0 to a2 in this embodiment (also shown in fig. 7).

In another embodiment, the error bits may have priority. In this case, if bit 0 is 1, bits 5 to 7 are always occupied with error codes ERR0 to ERR2 regardless of the value of bit 1.

With the embodiments of fig. 6 and 7, the information transmitted in the conventional AK protocol, such as information about the magnetic field strength or error codes, can therefore be transmitted further, and the resolution can additionally be increased, for which the corresponding phase information a0 to a2 is transmitted, wherein the same pulse sequence format as in the conventional AK protocol (for example, the pulse sequence format of fig. 3) can be used. Thus, the modified embodiment can be implemented, for example, by modifying firmware, i.e. providing a corresponding computer program, for example, on a corresponding data carrier, without having to modify hardware, for example, the current interface. This allows some embodiments to be implemented simply with existing hardware.

At least some embodiments are defined in the following examples:

example 1. an apparatus for transmitting rotational speed information, comprising:

signal processing means for receiving the magnetic field sensor signal, an

A current interface for transmitting a sequence of pulses of a current signal, wherein each sequence of pulses comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level,

wherein the signal processing means are arranged for detecting, based on the magnetic field sensor signal, a zero crossing of an extension curve of a magnetic field and a further point of the extension curve of the magnetic field and, upon detection of a zero crossing or a further point of the magnetic field, to actuate the current interface to transmit a pulse sequence,

wherein a first group of bits of the plurality of bits of a respective pulse sequence is marked with: is related to the pulse sequence transmitted upon detection of a zero-crossing or is related to the pulse sequence transmitted upon detection of a further point, and selects the information modulated onto the second group of bits of the plurality of bits of the respective pulse sequence in dependence on being related to the pulse sequence transmitted upon detection of a zero-crossing or upon detection of a further point. The different type of information for the second group of bits is therefore selected depending on whether it concerns the pulse sequence transmitted when a zero crossing is detected or the pulse sequence transmitted when a further point is detected.

Example 2. the apparatus of example 1, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits specifying: whether it concerns a pulse sequence transmitted when a zero crossing is detected.

Example 3. the apparatus of example 2, wherein the second group of bits includes a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

Example 4. the apparatus of any of examples 1-3, wherein the additional point of the magnetic field corresponds to an intersection through a threshold of the magnetic field, a global minimum of the magnetic field, and/or a global maximum of the magnetic field.

Example 5 the apparatus of any of examples 1 to 4, wherein if it concerns a pulse sequence transmitted upon detection of a further point, phase information is modulated onto the second group of bits, the phase information indicating: the pulse sequence is transmitted upon which further point of the magnetic field is detected.

Example 6. the device of any of examples 1-5, wherein information indicative of the strength of the magnetic field is modulated onto the second group of bits if it relates to a sequence of pulses sent at one zero crossing.

Example 7. the apparatus of any of examples 1-4, wherein the first bit set further flags whether an error occurred.

Example 8. the apparatus according to example 7, wherein,

if a pulse sequence transmitted at a zero crossing is involved and no error occurs, information indicating the strength of the magnetic field is modulated onto the second bit group, and

if no errors occur, relate to the pulse sequence transmitted at a further point of the magnetic field and no errors occur, phase information indicating at which point of the magnetic field the pulse sequence is transmitted is modulated onto the second bit group.

Example 9 the device according to example 7 or 8, wherein if an error occurs and relates to a pulse sequence transmitted at a zero crossing, an error code is modulated as information onto said second bit group, and if a pulse sequence transmitted at a further point of said magnetic field is referred to, said phase information is modulated onto said second bit group.

Example 10 the apparatus of example 8, wherein if there is an error, an error code is modulated onto the second group of bits as information.

Example 11. an apparatus for receiving rotational speed information, comprising:

a current interface for receiving a pulse train of a current signal, wherein each pulse train comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, and

signal processing means for processing the received pulse sequence, wherein the signal processing means are arranged for determining the type of information modulated onto a second group of bits of the plurality of bits from a first group of bits of the plurality of bits of the corresponding pulse sequence, and for evaluating the second group of bits from the determined type of information, wherein in the first group of bits there are marked: is related to the pulse sequence transmitted when a zero crossing of the extension curve of the magnetic field is detected or is related to the pulse sequence transmitted when a further point of the extension curve of the magnetic field is detected.

Example 12 the apparatus according to example 11, wherein the signal processing means is arranged to process a pulse train transmitted by the apparatus according to any one of examples 1 to 10.

Example 13 the apparatus of examples 11 or 12, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits indicating: whether it concerns a pulse sequence transmitted when a zero-crossing is detected.

Example 14. the apparatus of example 13, wherein the second group of bits includes a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

Example 15 the apparatus of any of examples 11 to 14, wherein the additional point of the magnetic field corresponds to an intersection through a threshold of the magnetic field, a global minimum of the magnetic field, and/or a global maximum of the magnetic field.

Example 16 the device of any of examples 11 to 15, wherein if the first bit group indicates a pulse sequence relating to a pulse sequence transmitted at a time of detection of one further point of the magnetic field, a type of the information as the phase information indicating at which further point of the magnetic field the pulse sequence has been transmitted is determined.

Example 17 the apparatus of any of examples 11-16, wherein the type of information that is information indicative of the magnetic field strength is determined if the first set of bits indicates a sequence of pulses that involves transmission upon detection of a zero crossing.

Example 18 the apparatus of any of examples 11-15, wherein the signal processing device is further configured to determine whether an error has occurred based on the first group of bits.

Example 19. the apparatus of example 18, wherein,

if the first group of bits indicates a pulse sequence which relates to a pulse sequence transmitted when a zero-crossing is detected and no error occurs, the type of information as information indicating the magnetic field strength is determined, and

if the first group of bits indicates that no error has occurred and relates to a pulse sequence transmitted at the detection of a further point of the magnetic field, the type of information is determined as phase information indicating at which point of the magnetic field the pulse sequence was transmitted.

Example 20. the apparatus of examples 18 or 19, wherein,

the type of information as error code is determined if the first group of bits indicates the presence of an error, if the first group of bits indicates a reference to a pulse sequence transmitted at a zero crossing, and if the first group of bits indicates a reference to a pulse sequence transmitted at a further point of the magnetic field, the type of information as phase information is determined.

Example 21 the apparatus of example 18 or 19, wherein the type of information that is an error code is determined if the first group of bits indicates that an error occurred.

Thus, examples 16 to 21 provide various possibilities for determining the type of information of example 11 based on the first group of bits.

Example 22. a method for transmitting rotational speed information, comprising:

the zero crossings and further points of the extension curve of the magnetic field are detected,

transmitting respective pulse sequences upon detection of the zero crossing and the further point of the magnetic field, wherein each pulse sequence comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, and

wherein marked in a first group of bits of the plurality of bits of a respective pulse sequence are: to the pulse sequence transmitted when a zero-crossing is detected or to the pulse sequence transmitted when a further point is detected, and to select the information modulated onto the second group of bits of the plurality of bits in dependence on whether the pulse sequence transmitted when a zero-crossing is detected or the pulse sequence transmitted when a further point is detected.

Example 23. the method of example 22, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits specifying: whether it concerns a pulse sequence transmitted at the detected zero crossing.

Example 24 the method of example 23, wherein the second group of bits includes a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

Example 25 the method of any of examples 22 to 24, wherein the additional point of the magnetic field corresponds to an intersection through a threshold of the magnetic field, a global minimum of the magnetic field, and/or a global maximum of the magnetic field.

Example 26 the method of any of examples 22 to 25, wherein if not related to a pulse sequence transmitted upon detection of a further point, phase information is modulated onto the second group of bits, the phase information indicating: at which further point of the magnetic field the pulse sequence is detected.

Example 27 the method of any one of examples 22 to 26, wherein information indicative of the strength of the magnetic field is modulated onto the second group of bits if it relates to a sequence of pulses sent at a zero crossing.

Example 28 the method of any of examples 22-25, wherein the first set of bits further flags whether an error occurred.

Example 29 the method of example 28, wherein,

if a pulse sequence transmitted at a zero crossing is involved and no error occurs, information indicating the strength of the magnetic field is modulated onto the second bit group, and

if no error occurs and a pulse sequence is transmitted at a further point of the magnetic field is involved, phase information indicating at which point of the magnetic field the pulse sequence was transmitted is modulated onto the second bit group.

Example 30 the method of example 28 or 29, wherein if there is an error and involves a pulse sequence transmitted at a zero crossing, an error code is modulated as information onto the second bit group, and if involves a pulse sequence transmitted at a further point of the magnetic field, the phase information is modulated onto the second bit group.

Example 31 the method of example 28 or 29, wherein if there is an error, an error code is modulated onto the second group of bits as the information.

Example 32 a method for receiving rotational speed information, comprising:

receiving pulse sequences, wherein each pulse sequence comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, wherein a first group of bits of the plurality of bits of a respective pulse sequence specifies: whether it concerns a pulse sequence transmitted upon detection of a zero crossing of the magnetic field or upon detection of a further value,

determining a type of information modulated onto a second group of bits of the plurality of bits of the corresponding pulse sequence based on the first group of bits, an

Evaluating information modulated onto the second group of bits corresponding to the determined type of the information.

Example 33 the method of example 32, wherein the method is arranged to process a pulse train transmitted by the method according to any one of examples 22 to 31.

Example 34 the method of example 32 or 33, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits indicating: whether it concerns a pulse sequence transmitted at the detected zero crossing.

Example 35 the method of example 34, wherein the second group of bits includes a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

Example 36. the method of any of examples 32 to 35, wherein the additional point of the magnetic field corresponds to an intersection through a threshold of the magnetic field, a global minimum of the magnetic field, and/or a global maximum of the magnetic field.

Example 37 the method of any one of examples 32 to 36, wherein if the first set of bits indicates a pulse sequence relating to a pulse sequence transmitted at a time of detection of one further point of the magnetic field, determining a type of the information as phase information indicating at which further point of the magnetic field the pulse sequence has been transmitted.

Example 38 the method of any of examples 32-37, wherein if the first set of bits indicates a sequence of pulses related to being transmitted when a zero-crossing is detected, determining the type of information as the information indicative of the magnetic field strength.

Example 39 the method of any of examples 32-36, wherein determining whether an error occurred is based on the first set of bits.

Example 40. the method of example 39, wherein,

if the first group of bits indicates a pulse sequence which relates to a pulse sequence transmitted when a zero-crossing is detected and no error occurs, the type of information as information indicating the magnetic field strength is determined, and

if the first group of bits indicates that no error has occurred and relates to a pulse sequence transmitted at the detection of a further point of the magnetic field, the type of information indicating at which point of the magnetic field the phase information of the pulse sequence was transmitted is determined.

Example 41 the method of example 39 or 40, wherein the type of information as the error code is determined if the first group of bits indicates that an error occurred, and the type of information as the phase information is determined if the first group of bits indicates that a pulse sequence transmitted at one further point of the magnetic field is involved.

Example 42 the method of example 39 or 40, wherein if the first group of bits indicates that an error occurred, determining a type of the information as the error code.

Thus, examples 37 to 42 provide various possibilities for determining the type of information of example 32 based on the first group of bits.

Example 43 a computer program having a program code which, when inserted on a processor, causes the method according to any of examples 22 to 42 to be performed.

Example 44. an electronically readable tangible data carrier having a computer program according to example 43.

Example 45. an apparatus for sending rotational speed information, comprising:

means for detecting the zero crossing and further points of the extension curve of the magnetic field, and

means for transmitting respective pulse sequences upon detection of a zero crossing and a further point of the magnetic field, wherein each pulse sequence comprises a first pulse having a first current level followed by a plurality of bit pulses, which bit pulses encode a plurality of bits at a second current level and a third current level,

wherein a first group of bits of the plurality of bits of a respective pulse sequence is marked with: is related to the pulse sequence transmitted when a zero-crossing is detected or is related to the pulse sequence transmitted when a further point is detected, and the information modulated onto the second group of bits of the plurality of bits of the respective pulse sequence is selected in dependence on the pulse sequence transmitted when a zero-crossing is detected or the pulse sequence transmitted when a further point is detected.

Example 46. the apparatus of example 45, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits specifying: whether it concerns a pulse sequence transmitted when a zero crossing is detected.

Example 47 the apparatus of example 46, wherein the second group of bits comprises a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

Example 48 the apparatus of any one of examples 45 to 47, wherein the additional point of the magnetic field corresponds to an intersection through a threshold of the magnetic field, a global minimum of the magnetic field, and/or a global maximum of the magnetic field.

Example 49 the apparatus of any one of examples 45 to 48, wherein if not related to a pulse sequence transmitted upon detection of a further point, phase information is modulated onto the second group of bits, the phase information indicating: at which further point of the magnetic field the pulse sequence is detected.

Example 50 the apparatus of any of examples 45 to 49, wherein information indicative of the strength of the magnetic field is modulated onto the second group of bits if it relates to a sequence of pulses sent at a zero crossing.

Example 51. the apparatus of any of examples 45 to 50, wherein the first set of bits further flags whether an error occurred.

Example 52. the apparatus of example 51, wherein,

if a pulse sequence transmitted at a zero crossing is involved and no error occurs, information indicating the strength of the magnetic field is modulated onto the second bit group, and

if no error occurs and a pulse sequence is transmitted at a further point of the magnetic field is involved, phase information indicating at which point of the magnetic field the pulse sequence was transmitted is modulated onto the second bit group.

Example 53. the device according to example 51 or 52, wherein, if there is an error and the pulse sequence transmitted at a zero crossing is involved, an error code is modulated as information onto the second bit group, and if the pulse sequence transmitted at a further point of the magnetic field is involved, the phase information is modulated onto the second bit group.

Example 54 the method of examples 51 or 52, wherein if there is an error, an error code is modulated onto the second group of bits as information.

Example 55. an apparatus for transmitting rotational speed information, comprising:

means for receiving a sequence of pulses, wherein each sequence of pulses comprises a first pulse having a first current level followed by a plurality of bit pulses encoding a plurality of bits at a second current level and a third current level, wherein a first group of bits of the plurality of bits of the respective sequence of pulses specifies: whether it concerns a pulse sequence transmitted upon detection of a zero crossing of the magnetic field or upon detection of a further value,

means for determining a type of information modulated onto a second group of bits of the plurality of bits of the corresponding pulse sequence based on the first group of bits, an

Means for evaluating the information modulated onto the second set of bits corresponding to the determined type of the information.

Example 56 the apparatus of example 55, wherein the apparatus comprises a processor configured to process the pulse train transmitted by the apparatus according to any one of examples 45 to 54.

Example 57 the apparatus of examples 55 or 56, wherein the number of bits per pulse sequence is 9, the second bit of the plurality of bits specifying: whether it concerns a pulse sequence transmitted when a zero-crossing is detected.

Example 58 the apparatus of example 57, wherein the second group of bits includes a sixth bit, a seventh bit, and an eighth bit of the plurality of bits.

Example 59. the apparatus of any of examples 55 to 58, wherein the additional point of the magnetic field corresponds to an intersection through a threshold of the magnetic field, a global minimum of the magnetic field, and/or a global maximum of the magnetic field.

Example 60 the device of any of examples 55-59, wherein if the first set of bits indicates a pulse sequence relating to a pulse sequence transmitted at a detection of one further point of the magnetic field, then determining the type of information as phase information indicating at which further point of the magnetic field the pulse sequence has been transmitted.

Example 61 the apparatus of any of examples 55-60, wherein the type of information that is information indicative of the magnetic field strength is determined if the first set of bits indicates a sequence of pulses that involves transmission upon detection of a zero crossing.

Example 62. the apparatus of any of examples 55 to 59, wherein it is further determined whether an error occurred based on the first group of bits.

Example 63. the apparatus of example 62, wherein,

if the first group of bits indicates a pulse sequence which relates to a pulse sequence transmitted when a zero-crossing is detected and no error occurs, the type of information as information indicating the magnetic field strength is determined, and

if the first group of bits indicates that no error has occurred and relates to a pulse sequence transmitted at the detection of a further point of the magnetic field, the type of information indicating at which point of the magnetic field the phase information of the pulse sequence was transmitted is determined.

Example 64 the apparatus of examples 62 or 63, wherein the type of information as the error code is determined if the first group of bits indicates that an error occurred, and the type of information as the phase information is determined if the first group of bits indicates that a pulse sequence transmitted at one further point of the magnetic field is involved.

Example 65. the apparatus of examples 62 or 63, wherein if the first group of bits indicates an error, the type of information that is an error code is determined.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention as set forth in the claims. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.