DE102018209374A1 - Level measuring device with combined device display unit for displaying status information and output of a verification code - Google Patents

Abstract

A fill level measuring device (10) with an authentication unit (24) is proposed, wherein the authentication unit (24) generates a verification code (26) and generates an authentication information (30) in agreement with a received confirmation code (28), which access by a user or an external terminal (44) on the level gauge (10) legitimized. The verification code (26) is coded by a signaling unit (32) and thus a signal generator (36) is actuated which transmits the coded verification code (26), for example as a light signal sequence (38) or a vibration sequence. In this case, the same signal generator (36) can also be used for the presentation of status information (42) of the level measuring device (10).

Description

Technical area

The invention relates to level measuring devices, flow measuring devices, pressure measuring devices and point level sensors. In particular, the invention relates to authentication of a user or an external terminal on a field device.

Background of the invention

Level measuring devices are often used to monitor industrial processes and are installed at remote locations. Before commissioning, it is usually necessary to parameterize the devices for proper functioning. This means that, for example, a certain configuration is loaded into an internal memory of the level measuring device or certain settings are adjusted and variables are set. For this purpose, the level measuring device is connected, for example, to an external terminal or an operating unit. Since a configuration of a level measuring device can have an important prerequisite for the safe and proper functioning of a system, unauthorized access by unauthorized devices or people is an essential security-relevant aspect of such a solution.

Wireless transmission protocols allow, for example, external terminals for parameterization to be connected to a level measuring device. Frequently, protocols such as WLAN or Bluetooth are used. Authorization takes place, for example, by entering a user name and a password or also a PIN, which is compared with a database of permitted user names and passwords. It is known to improve the quality of access control so-called two-factor authentication. The concept here is often that two different, ideally independent, verification mechanisms are used to identify a user or an external terminal. In the DE 102017116161 A1 For example, techniques for performing two-factor authentication in a process plant are presented.

Presentation of the invention

Embodiments of the invention can simplify level gauges with increased safety and thus reduce effort and costs for the production and operation of level gauges. The invention described below is based on the following considerations. Basically, the possibility of using a wireless protocol offers the possibility that a service technician may be in the vicinity of the field device or level gauge and connects to the level gauge by means of an external terminal. For example, to establish a wireless connection, for example via WLAN or Bluetooth, a verification code can first be generated, which then has to be confirmed by a user via the input into an external terminal.

However, the known solutions are often designed in such a way that either the external terminal must support the reception of this code, which requires appropriate functionalities. Another possibility is, for example, a display directly on the level measuring device, which, for example, shows alphanumeric characters, which the user then enters into the external terminal and sent back to the level measuring device for confirmation. This usually requires additional retrofitting or additional display components on the device, which are correspondingly expensive and take up space on the generally relatively small housings of the level measuring devices.

Therefore, a filling level measuring device is proposed that has an authentication unit for authenticating a user or an external terminal. The term "level gauge" is intended to describe all embodiments of devices for detecting, measuring or for detecting levels of liquids, fluids or solids in containers or other containers. These can be powered, for example, for power only via a 4-20 mA bus or be designed as battery-powered devices. The authentication unit can be, for example, via a microcontroller and corresponding software together with the necessary data interfaces. This authentication unit is set up to generate a verification code and to receive a confirmation code.

So if a user wants to connect to the level measuring device, a random generator, for example, generates an alphanumeric code or a sequence of digits in the authentication unit. This verification code can be issued and compared with a confirmation code that the authentication unit receives from the external terminal or from the user. The confirmation code is compared with the verification code originally generated. If the authentication unit determines that the verification code and confirmation code correspond, that is, for example, are identical, then the authentication unit generates authentication information.

This authentication information can be, for example, the setting of a flag, the generation of a message or the generation of a data record. The authentication information may be used by downstream processes, assemblies, or algorithms to allow or deny corresponding access rights and data transfers based thereon. Furthermore, the level measurement device has a signaling unit with a signal generator. In this case, the signaling unit is configured to receive the verification code from the authentication unit and to encode it in a control sequence for the signal generator. The signaling unit thus translates the, for example, randomly generated verification code into electrical control signals for the signal generator. The signaling unit is further configured to control the signal generator for transmitting a signal sequence on the basis of the control sequence.

A signal generator can be understood here as a component that generates a wide variety of physical or other signals and outputs or forwards to the outside. These may be, for example, light signals, electromagnetic signals, acoustic signals, mechanical signals such as vibrations or other vibrations, but also more complex optical displays. The coding can be done using known protocols or standards such as Morse code or similar methods, but can also have complex combinations of several of the mentioned signal forms or coding specifications.

An advantage can be seen here that such a signal generator can be designed to be comparatively small and space-saving, in particular because very simple coding methods are applicable. In other words, can be dispensed with large-scale displays and instead, for example, simple LEDs or acoustic encoders are used. In one embodiment, the signal transmitter is designed to be light-emitting or optical. For example, an LED can blink, d. H. be periodically switched off and on by a chronological sequence of switching states. Taking the example of Morse code coding, a series of alphanumeric characters can be mapped at appropriate time intervals to separate each character by a defined sequence of on and off states. A user can either decode it himself with appropriate knowledge. Alternatively, according to one example, an external terminal has a camera unit, which supports by a corresponding recognition software, evaluates the luminous sequence of the signal generator and decodes into the verification code.

In one embodiment, the signal generator is additionally configured to signal status information of the level measuring device. In other words, for example, an LED or a combination of several LEDs will be used to indicate operating states or status information of the level measurement device. For a further purpose, therefore, the same LED or the same set of LEDs, for example in a logically separate mode, is now used as a signal transmitter for transmitting the verification code. In other words, advantageously already existing components are advantageously used for a further function, without the need for additional hardware or space. In this case, only a corresponding extension of the software on the level gauge would be necessary.

In one embodiment of the invention, the signal transmitter sends out the coded verification code by mechanical oscillations or vibrations. Similar to the LED, it is possible that a certain chronological sequence of vibrations is generated, which represents the encoded verification code. In one example, a user can recognize these vibrations simply by touching the housing of the level measuring device. According to a further example, the external terminal can be brought into direct mechanical contact with the housing of the level measuring device, the external terminal having a corresponding sensor for detecting mechanical vibrations. In addition, analogous to the evaluation of the optical signals, detection and coding of the sent verification code can take place in the external terminal.

In one embodiment, the signal transmitter transmits the encoded verification code by switching a relay. The background is that relays for switching modules and signals as well as for communication with a control panel are already available in many level measuring devices. These relays can similarly be used in a double function as signal transmitters for outputting the coded verification code. For example, the switching states influenced by the relay can be detected and the verification code can be decoded from this.

In one embodiment, the signaling unit encodes the verification code and controls the signal generator in such a way that an external terminal can receive the encoded verification code and can generate a confirmation code by decoding. External terminals are regularly used, on the one hand to be able to make appropriate entries via a keyboard or similar mechanisms, and on the other hand to support parameterization and authentication. For this purpose, both the field device with the signaling unit and the external terminal should use the same coding in order to receive the verification code in the external terminal and to be able to calculate the confirmation code in the next step. In one example, the external terminal transmits the calculated confirmation code back to the level measuring device. This can be done in different ways, for example over the same wireless interface, but also over other transmission paths such as a connected 4-20mA fieldbus.

In one embodiment, the coding comprises a time sequence of switching states. In other words, a serial transmission of the coded information takes place over time. This can be done synchronously or asynchronously. The advantage here is that very simple and inexpensive hardware can be used. In one embodiment, the control sequence has digital switching states of the signal generator. As already mentioned in the example of the Morse code, an effective transmission can already take place by simply periodically switching off and switching on the signal generator in a specific time frame. In a further embodiment, the control sequence has a number of n defined switching states. In other words, a limited number of switching states are defined. This can be, for example, luminous intensities of optical displays such as LEDs, but also different vibration frequencies or vibration intensities. This can have the advantage that more information or data can be transmitted in a shorter time due to a larger number of possible switching states.

Furthermore, a device display unit is presented, which has a signal transmitter, as has been described with regard to its features heretofore and below, including the design variants. In one embodiment, the signal transmitter is designed as an LED status display. The signal generator is configured to display status information of a device and, optionally in a separate mode, to send a signal sequence representing a verification code via a received control sequence. In one example, this may be, for example, a flashing corresponding to the coding, that is to say switching on and off one or more LEDs.

It is to be understood that features of the level measuring device, as described above and below, can also be features of the device display unit and vice versa.

list of figures

• 1 zeigt ein Füllstandmessgerät mit mehreren LED-Statusanzeigen und zwei Bedienelementen.
• 2 zeigt eine Authentifizierungseinheit und eine Signalisierungseinheit samt Signalgeber eines Füllstandmessgerätes.
• 3 zeigt eine Erfassung eines Zustandes von LED-Statusanzeigen durch eine Kameraeinheit eines externen Terminals.

Exemplary embodiments of the invention are described in detail below with reference to the accompanying figures. Neither the description nor the figures are to be interpreted as limiting the invention.

• 1 shows a level meter with several LED status indicators and two controls.
• 2 shows an authentication unit and a signaling unit together with signal transmitter of a level measuring device.
• 3 shows a detection of a state of LED status displays by a camera unit of an external terminal.

The drawings are only schematic and not to scale. Basically, identical or similar parts are provided with the same reference numerals.

Detailed description of embodiments

1 shows in a schematic simplified manner a level gauge 10 with a housing 12 and a connection 14 , This connection 14 For example, for connecting the level gauge 10 with a fieldbus (not shown here) serve. In the lower area is an example of a radar measuring unit 16 provided, where a variety of measurement technologies in terms of level, pressure, flow and similar sizes are possible. On top of the case 12 Here are two examples of control elements 18 given, for example, as buttons, sliders can be executed or represent other types of interfaces with a user or an external device. In addition, there are several signal transmitters 20 provided, which are designed in the example shown here as LEDs.

These signalers 20 , specifically one or more LEDs here, are provided in many previous level measuring devices for displaying an operating state or for displaying status information. Typical level gauges 10 often have due to the limited space on the container preferably small housing 12 and thus a comparatively small available area for the signal generator 20 or LED status indicators. Accommodating additional elements may require miniaturization, which in many cases may be inconvenient for servicing by service personnel. For parameterization of a level measuring device 10 It is advantageous to use an external device with the level gauge 10 connect to. This can be over, for example a wireless protocol like Bluetooth. For this purpose, the level measuring device 10 a Bluetooth module 22 intended.

For example, a user may have an external terminal 44 (see also 3 ) via the bluetooth module 22 with a username and password on the level gauge 10 Sign in. To prevent improper parameterization or unauthorized access to the level gauge 10 To avoid, a so-called two-factor authentication is additionally provided. Ideally, this should be ensured via a separate mechanism that a user actually in the immediate physical vicinity of the level gauge 10 staying. For this purpose, for example, a verification code (see 2 ) are generated, the only in local or physical proximity of the level gauge 10 is receivable and by the user as a confirmation code (see 2 ) to the level gauge 10 is returned.

In 2 A simplified presentation of an extended authentication of a user or an external terminal is presented. For this purpose, the level gauge 10 an authentication unit 24 on. This is to ensure that only authorized users or authorized external terminals 44 Access to the level gauge 10 to get. The authentication unit 24 is set up, a verification code 26 to generate and spend. Generating the verification code 26 can be done for example via a random number generator, but also via, for example, a list of predefined codes. In one example, the verification code 26 be an n-digit alphanumeric code, so for example a sequence of numbers and / or letters and / or special characters.

A user or external terminal 44 (please refer 3 ) receives the verification code 26 and generates a confirmation code based thereon 28 that is in response or feedback from the authentication unit 24 Will be received. The authentication unit 24 is set up, the received confirmation code 28 with the verification code 26 to compare. For example, if both codes match, generates the authentication unit 24 an authentication information 30 , which may be, for example, a record, message, flag, or the like that provides access by the user or external terminal 44 on the level gauge 10 allow or block. In one example, the verification code 26 and the verification code 28 corresponding codes, which do not necessarily have to be identical. Here, only by calculation methods, for example, a relationship between the two codes can be determined.

In one example, the external terminal is 44 additionally set up, a conversion of the verification code 26 in a confirmation code 28 according to a defined rule. The same regulation is also stored in the level gauge, which can additionally provide a safety-relevant restriction to certain, approved external terminals. The verification code 26 is from a signaling unit 32 received and in a control sequence 34 for a signal generator 36 coded. The coding may for example be based on known mechanisms, such as simple Morse code or similar suitable protocols. In this case, according to one example, a time sequence of simple on-off switching states can be generated. According to one example, also a plurality of defined switching states or intensities can be defined.

The signal generator 36 sends a signal sequence 38 For example, light signals, acoustic signals, vibrations, mechanical signals, haptic or other suitable signal forms. In one example, the signal generator generates 36 Vibrations, for example, simply by touching the housing 12 of the level measuring device 10 can be detected by the hand of a user. According to an example, for example, a certain number can be generated by a corresponding number of signal sequences transmitted in succession 38 be represented. A number 5 is, for example, five vibration pulses or light pulses emitted by the signal generator at a defined time interval 36 shown. Similarly, more complex characters or strings can be transmitted. According to one example, the transmission of the code after a long pause in time is used as a signal sequence 38 from the signal generator 36 sent out repeatedly.

Another idea is to use possibly existing LED status indicators to send out a verification code 26 , Due to the limited space available is thus no additional element for displaying or sending a verification code 26 provided. In other words, a simple retrofit by updating a software on the level gauge 10 conceivable without having to change the hardware. In 2 is a status unit for this purpose 40 of the level gauge 10 provided that is set up, information about the operating state in the form of status information 42 provide. This status information 42 be to the signaler 36 transmitted using the same hardware signal sequences 38 sends out the status information 42 represent. According to one example, the signaling unit of the level measuring device 10 executed between a mode for displaying status information 42 and a mode for displaying a verification code 26 switch.

According to one example, the signal generator 36 designed as a display. In this variant, simple codes such as QR codes can be displayed and via an external terminal 44 be recorded. Another possibility would be the representation in the form of alphanumeric characters that can be read out by a user. In another example, the signal generator 36 designed as an acoustic transmitter. In this case, audio signals are output which are encoded in a similar manner. According to another example, the signal generator 36 connected to a fieldbus, for example a 4-20 mA fieldbus, and gives the verification code 26 as a signal sequence 38 on the fieldbus. A programmable logic controller PLC in a control center can receive this information, buffer it if necessary and forward it to a user. According to another example, the signal generator 36 executed as one or more relays, the relays changing the switching state the coded verification code 26 for example to a control center and / or programmable logic controller PLC.

In 3 An embodiment is shown in which an external terminal 44 a camera unit 46 having. This camera unit 46 is executed, signals 38 of the signal generator implemented by LEDs 36 to detect or to detect. This means that the camera unit 46 for example, an on or an off state of the signal generator 36 or the LED or different light intensities. So if the level gauge 10 with the signal generator 36 a verification code 26 sends out over a certain period of time, the camera unit 46 at the terminal 44 collect the sequence over a period of time and from the information the verification code 26 determine.

In one example the signal transmitter sends 36 a sequence of tones of different frequencies, which are received by an external microphone unit of an external terminal and decoded by the external terminal. In this way, even more complex code sequences can be transmitted with a correspondingly higher level of security.

In addition, it should be noted that "encompassing" does not exclude other elements or steps, and "a" or "an" does not exclude a multitude. It should also be appreciated that features or steps described with reference to any of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limiting

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102017116161 A1 [0003]

Claims (11)

Level measuring device (10), having - an authentication unit (24) for authenticating a user or an external terminal (44); wherein the authentication unit (24) is set up to generate a verification code (26) and to receive a confirmation code (28), to compare the received confirmation code (28) with the verification code (26) and, based on the comparison, to provide authentication information (30) to generate; - A signaling unit (32) with a signal generator (36), the signaling unit (32) being configured to receive the verification code (26) from the authentication unit (24) and to code it into a control sequence (34) for the signal generator (36) ; wherein the signaling unit (32) is further configured to control the signal transmitter (36) for transmitting a signal sequence (38) based on the control sequence (34). Level gauge (10) according to Claim 1 wherein the signal generator (36) is designed to be light-emitting or optical. Level measuring device (10) according to one of the preceding claims, wherein the signal transmitter (36) is additionally configured to signal status information (42) of the level measuring device (10). Level measuring device (10) according to one of the preceding claims, wherein the signal transmitter (36) emits the signal sequence (38) as a mechanical movement or vibration. Level measuring device (10) according to one of the preceding claims, wherein the signal transmitter (36) transmits the signal sequence (38) by switching a relay. Level measuring device (10) according to one of the preceding claims, wherein the signaling unit (32) encodes the verification code (26) and controls the signal transmitter (36) such that an external terminal (44) receives the encoded verification code (26) and decodes one Can generate confirmation code (28). Filling level measuring device (10) according to one of the preceding claims, wherein the coding comprises a time sequence of switching states. Level measuring device (10) according to one of the preceding claims, wherein the control sequence (34) has digital switching states of the signal generator (36). Filling level measuring device (10) according to one of the preceding claims, wherein the control sequence (34) has a number of n defined switching states. Device display unit with a signal transmitter (36); the signal transmitter (36) being configured to display status information (42) of the device and to transmit a coded verification code (26) via a control sequence (34) received by the signal transmitter (36). Use the device display unit according to Claim 10 in a level measuring device, a flow measuring device, a pressure measuring device or a point level sensor.

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