DE102006026379A1 - Measured value selecting method for use in e.g. diagnostic tester, involves selecting value produced by either digital evaluation unit or analog evaluation unit as measuring value based on form of signals adjacent to input - Google Patents

Abstract

The method involves receiving an analog or digital signal by an input (101). The analog or digital signals are evaluated by an analog evaluation unit (102) and a digital evaluation unit (104). A value produced by either the digital evaluation unit or the analog evaluation unit is selected as a measuring value based on a form of the signals adjacent to the input. A selected measured value is displayed on a display (107) and is outputted at an output (108). An independent claim is also included for a measuring device comprising an input.

Description

The The invention relates to a method for selecting a measured value in one Measuring device and a corresponding measuring device according to the preamble of claim 6.

State of the art

Measuring devices or Diagnostic tester for troubleshooting on vehicles are in the prior art in different versions common. They usually become to check the electrical properties of sensors by measuring the signal voltage used, despite extensive methods of diagnosing the components in the assigned control unit often still necessary is. Usually the measurement is carried out with a voltmeter that acts as a stand alone instrument or part run a test system can be. This makes it possible the functionality prove the sensor, but also by measuring on connectors in the wiring harness the signal transmission right up to the control unit to check.

Increasingly sensors are used instead of analog signal interfaces with digital Signal interfaces provided. At the analog interface is the output of the sensor e.g. in the voltage range of 0 ... 5 V shown. For digital interfaces are conceivable different coding, one standard solution is a so-called SENT interface for automotive applications ("Single Edge Nibble Transmission "for Automotive Applications, SAE J2716). The data gets into shape of pulses whose length usually each comprise 4 bits, transmitted. Preferably, sensors with a more complex signal processing with a digital signal interface equipped, typical representatives of such sensors are the Air mass meter and the accelerator pedal encoder.

digital Interface have advantageous properties, e.g. a constant high resolution too for little ones Signal values, no errors due to interference signals, elimination of errors by D / A conversion in the sensor and A / D conversion in the control unit, transmission of status information from the sensor to the control unit etc.

In Vehicles are expected to be during a longer transition period Sensors that have either analog or digital interfaces, to be built in. Especially in workshops that repair older vehicles and not over the information provided by the vehicle manufacturer, the assignment of the Sensors are not undoubtedly done, since analog and digital sensors, the for the same Use are provided, usually externally are configured the same and also have the same electrical connections. From the outside is therefore indistinguishable, whether a sensor with an analog or digital interface. Is to a typical analog voltmeter connected to a digital interface, an implausible reading is the consequence and vice versa.

Disclosure of the invention

The The invention relates to a method for selecting a measured value in one Measuring device and a corresponding measuring device with the features the independent one Claims. Advantageous embodiments are the subject of the dependent claims.

According to the invention is at a measuring device having an input for receiving an analog or digital signal and an analog evaluation unit and a has digital evaluation unit for evaluating the signal, as Measured value in dependence either one of the type of input signal the digital evaluation unit generated or one of the analog Evaluation unit generated value selected. All can be achieved with the invention Types of measuring devices, in particular measuring devices, diagnostic testers or test systems, especially in the automotive sector. Such measuring devices are usually used during service in the Workshop area for troubleshooting on vehicles, especially on ECUs used in vehicles. Thus, an improved and faster Diagnosis of sensors using a digital interface to signal transmission to the associated control unit equipped, possible. The measuring device automatically detects, according to the invention, which type connected by sensor, and selects the appropriate reading out according to the im following explained advantageous Developments of the invention can be treated.

preferably, becomes the selected reading displayed on a display and / or output at an output. When the reading is displayed, the user can quickly and easily read the measured value. It is also possible that the measured value an output other than a display additionally or optionally issued is, then a further processing, in particular storage, graphical representation, etc. in a connected system, eg. a computer, possible is.

Advantageously, the selected measured value is further processed in the measuring device and the further processed value is displayed on a display and / or output at an output. The further processing can in particular in the Art a conversion, but also storage, etc. take place. This advantageously extends the field of application of the invention.

Conveniently, becomes the selected reading for further processing depending on a source of the signal converted into a physical value. As signal sources, for example, various sensors come in a motor vehicle in question. Based on the type of sensor can the measured value is then converted into a physical value, before the display or output takes place. For example, instead of the voltage of a temperature sensor the corresponding temperature are displayed. An extension proposes standard conversions the digital signal values into physical values in the measuring device to store, e.g. Conversion into an air mass for one Air mass meter. about a e.g. menu-guided selection by the user then the digital signal value as a physical Value displayed and checked for plausibility. This can be done in a memory parameters are stored, which is a conversion enable. This makes the evaluation of the displayed value advantageous to the user simplified, since a plausibility check can easily be carried out.

It is particularly useful if the source of the signal is determined by the signal. When a In particular, digital sensor in the signal transmission also transmits an identification feature can this feature can be used to advantage in the corresponding Convert automatically. Thus, the operation of a measuring device according to the invention is advantageously facilitated, because a misuse by the user, for example in shape a faulty selection of a sensor can be avoided.

A has measuring device according to the invention an input for recording an analog or digital signal, an output to the output of a measured value as well as an analogue Evaluation unit for evaluating the signal, a digital evaluation unit for evaluating the signal, a determining unit for determining the type of signal and a selection unit for selecting either of the value generated by the digital evaluation unit or of the analog evaluation unit generated value as a measured value in dependence on the type of signal. The device according to the invention has in particular the said advantages of the method according to the invention.

According to one advantageous embodiment, the output closes a display to display the reading or it is an additional one Ad intended to be displayed. In this case, the user can read the measured value quickly and easily Likewise it is possible that the reading on an output other than an indicator in addition or is optionally issued, in which case a further processing, in particular Storage, graphical representation etc. in a connected system, eg a computer, possible is.

It is advantageous if the digital evaluation unit has a variable Program routine has. The digital evaluation unit could then be designed as a computing unit, which decodes the provided digital sensor interface makes, whereby by a change the program routine (update) also additional decoding possibilities for new ones digital interfaces can be provided. As a result, a device according to the invention be adapted again and again to new conditions and purposes.

It is preferred when one with the digital evaluation unit for generating the reading of the cooperating memory is provided. In the store can Standard conversions of the digital signal values into physical Values are stored, e.g. Conversion into an air mass for an air mass meter. Over a e.g. menu-guided selection by the user then the digital signal value as a physical Value displayed and checked for plausibility. These are in the Memory, for example, stores parameters that contain a conversion enable. It makes sense if these parameters also, in particular through an update, changeable are.

It is appropriate if two elements from the group, the analog evaluation unit, the digital evaluation unit, the determination unit, the selection unit, the display and the memory comprises, integrated in a circuit are. It is particularly appropriate, the digital evaluation unit and the determination unit to combine. Likewise, it is particularly useful the Selection unit, the determination unit and / or an intended To combine display. With that you can Components are saved, resulting in a reduction of design effort as well as the manufacturing costs can.

Of Further, the measuring device advantageously has more Means to perform one of the mentioned embodiments the method according to the invention.

The inventive method and the device according to the invention According to the invention in the automotive sector, particularly used in connection with the testing of sensors.

Further advantages and embodiments of the invention will become apparent from the description and the enclosed drawing.

It understands that the mentioned above and the features to be explained below not only in the specified combination, but also in other combinations or alone, without to leave the scope of the present invention.

Brief description of the drawings

1 shows a schematic representation of a first embodiment of a measuring device according to the invention;

2 shows a schematic representation of a second embodiment of a measuring device according to the invention; and

3 shows a schematic representation of a course of a digital signal.

Embodiment (s) the invention

in the The following is intended to illustrate the invention and in particular its advantages an illustrated embodiment be explained in more detail. Identical elements are provided with the same reference numerals.

This in 1 in one embodiment schematically illustrated measuring device 100 is for detecting and processing one at an entrance 101 of the meter 100 formed signal adjacent, wherein the signal can be analog or digital. The measuring device 100 also has an analogue evaluation unit 102 , a determination unit 103 , a digital evaluation unit 104 , a memory cooperating with the digital evaluation unit 105 , a selection unit 106 , an ad 107 as well as an exit 108 on.

The analogue evaluation unit 102 is designed to be from the entrance 101 applied signal to generate a value. This value is in the example shown to the selection unit 106 to hand over.

The determination unit 103 is designed to the nature of the entrance 101 to determine the applied signal. The determination unit distinguishes here 103 between an analog signal and a digital signal. The type of signal is also sent to the selector 106 transmitted.

The digital evaluation unit 104 is designed to be from the entrance 101 applied signal to generate a value, this generation can only be successfully performed, if it is a digital signal. For pure analog signals that are not digital signals, the digital evaluation unit can not generate a value. The intended memory 105 works with the digital evaluation unit 104 together to that of the digital evaluation unit 104 generated value before passing to the selection unit 106 to convert into a physical value.

The selection unit 106 chooses the one of the analog evaluation unit on the basis of the result of the determination transmitted by the determination unit 102 or the one from the digital evaluation unit 104 generated value and gives this both to the display 107 as well as to the exit 108 further. The ad 107 is formed in the described embodiment as an optical display panel or display. The user can see that on the display 107 read off the value shown and that at the output 108 output measured value in a connected device, in particular a computer system.

In 2 is another embodiment of the measuring device according to the invention designed as a measuring device and a total of 200 designated. The measuring device 200 also has an entrance 101 as well as an analogue evaluation unit 102 on. Furthermore, the meter points 200 the memory 105 up with the combined determination and digital evaluation unit 234 interacts. Furthermore, the selection unit and the output configured as a display are in a selection and display unit 2678 combined.

That at the entrance 101 applied signal is sent to the analogue evaluation unit 102 and the destination and digital evaluation unit 234 transmitted. From both units, as related to 1 described, values generated and sent to the selection and display unit 2678 transmitted. It is understood that the determination and digital evaluation unit 234 can only produce a value if the signal is a digital signal.

The selection and display unit 2678 is designed in such a way that it always matches that of the analogue evaluation unit 102 indicates transmitted value as a measured value, if not from the determination and digital evaluation unit 234 a value is also generated and transmitted. Used by the determination and digital evaluation unit 234 a value to the selection and display unit 2678 transmitted, this is displayed as a measured value. In this sense, the generation of a digital value also determines that it is a digital signal. Likewise, it can also be said that a determination unit in the selection and display unit 2678 is integrated and based on the two generated values determines whether the applied signal is an analog or a digital signal. In the In this sense, a determination is made by checking whether a value has been generated by the digital evaluation unit. If a value has been generated by the digital evaluation unit, it can be determined that the applied signal is a digital signal.

The measuring device described in the present embodiment 200 indicates in memory the memory 105 on. This store 105 is designed for the standard conversion of physical values of the digitally available signal. For example, via a menu-guided selection, with an input unit not shown here and the selection and display unit 2678 interacts and by a user of the meter 200 is operable, the value of the digital signal can be displayed as a physical value and checked for plausibility. These are in the memory 105 Parameters saved that allow a conversion. Likewise, an automatic conversion based on the signal source is possible.

It is expedient if the determination and digital evaluation unit 234 additionally designed to be one at the entrance 101 detected signal, which is intended as an update signal, detects and processed accordingly. This makes it possible, for example, one in the determination and digital evaluation unit 234 or in the selection and display unit 2678 and / or in memory 105 to change or update stored program routines and / or parameters.

The described embodiments of the measuring devices 100 and 200 can preferably be used in the automotive sector, for example in a workshop, and in particular for testing sensors.

The in the diagram off 3 shown embodiment of a course of a digital signal 302 is over a timeline 304 applied. An intensity axis is with 305 designated. It is a digital signal according to a SENT interface for automotive applications. The data is transmitted in the form of pulses whose length generally comprises 4 bits each time.

The signal 302 includes in chronological order first a first section 306 for synchronization and calibration with a period length of 168 μs. This is followed by a first signal section 308 and a second signal section 310 each with a length of 3 times 36 μs and a data size of 12 bits each. The signal 302 then has a section 312 with a CRC checksum and a final section 314 for a status and for communication with a period length of 36 μs each and a data volume of 4 bits each.

It is envisaged that the first signal section 308 a first date 316 , a second date 318 and a third date 320 includes. These three dates 316 . 318 . 320 each have a period length of 36 μs and a data size of 4 bits. Accordingly, the second signal section 310 a first date 322 , a second date 324 and a third date 326 each having a period length of 36 μs and a data size of 4 bits.

The signal has a total length of 456 μs, which is usually a minimum length of such signals whose length can be a maximum of up to 816 microseconds in this embodiment. An encoding of each transmitted date 316 . 318 . 320 . 322 . 324 . 326 with a data size of 4 bits consumes x times 3 μs plus an offset of 36 μs, where x is an integer from 0 to 15.

If a digital signal 302 with a like in 3 shown course as a signal in the in 1 or 2 shown measuring device 100 respectively. 200 it is through the digital evaluation unit 104 or through the digital determination and evaluation unit 234 decodable and as decoded information on the display unit 107 or the selection and display unit 2678 representable and at the exit 108 dispensable.

100

gauge

101

entrance

102

analog evaluation

103

determining unit

104

digital evaluation

105

Storage

106

selector

107

display unit

108

output

200

gauge

234

destination and digital evaluation unit

2678

Selection- and display unit

302

digital signal

304

timeline

305

intensity axis

306

synchronization and calibration section

308

first signal section

310

second signal section

312

checksum section

314

Status- and communication section

316

first date

318

second date

320

third date

322

first date

324

second date

326

third date

Claims (11)

Method for selecting a measured value in a measuring device ( 100 ; 200 ), which has an entrance ( 101 ) to record an analog or digital ( 302 ) Signal and an analogue evaluation unit ( 102 ) and a digital evaluation unit ( 104 ; 234 ) for evaluating the signal, wherein as a measured value depending on the nature of the input ( 101 ) signal either one from the digital evaluation unit ( 104 ; 234 ) or one of the analog evaluation unit ( 102 ) value is selected. Method according to claim 1, characterized in that the selected measured value is displayed on a display ( 107 ; 2678 ) and / or at an output ( 108 ; 2678 ) is output. A method according to claim 1, characterized in that the selected measured value in the measuring device ( 100 ; 200 ) and the processed value on a display ( 107 ; 2678 ) and / or at an output ( 108 ; 2678 ) is output. A method according to claim 3, characterized in that the selected measured value for further processing in dependence on a source of the signal ( 302 ) is converted into a physical value. Method according to claim 4, characterized in that the source of the signal ( 302 ) based on the signal ( 302 ) is determined. Measuring device ( 100 ; 200 ) with an input ( 101 ) for recording an analog or digital signal, an output ( 108 ; 2678 ) for outputting a measured value and an analog evaluation unit ( 102 ) for evaluating the signal ( 302 ), characterized by a digital evaluation unit ( 104 ; 234 ) for evaluating the signal ( 302 ), a determination unit ( 103 ; 234 ) for determining the type of signal ( 302 ) and a selection unit ( 106 ; 2678 ) for selecting either of the from the digital evaluation unit ( 104 ; 234 ) or of the analog evaluation unit ( 102 ) as a measured value depending on the type of signal ( 302 ). Measuring device ( 100 ; 200 ) according to claim 6, characterized in that the output ( 108 ; 2678 ) an ad ( 107 ; 2679 ) for displaying the measured value or an additional display ( 107 ) is provided for display. Measuring device ( 100 ; 200 ) according to claim 6 or 7, wherein the digital evaluation unit ( 104 ; 234 ) has a changeable program routine. Measuring device ( 100 ; 200 ) according to any one of claims 6 to 8, characterized by a with the digital evaluation unit ( 104 ; 234 ) memory cooperating to generate the measured value ( 105 ). Measuring device ( 100 ; 200 ) according to one of claims 6 to 9, characterized in that at least two elements from the group comprising the analog evaluation unit ( 102 ), the digital evaluation unit ( 104 ; 234 ), the determination unit ( 103 ; 234 ), the selection unit ( 106 ; 2678 ), the ad ( 107 ; 2678 ) and the memory ( 105 ), in a circuit ( 234 ; 2678 ) are integrated. Use of a method according to one of claims 1 to 5 or a device according to a the claims 6 to 10 to check sensors in the automotive sector.