AUTHOROUGH SENSOR DEVICE WITH EXTENSION MODULES

Description

[0001] The invention relates to a sensor device for determining process variables in an industrial environment, comprising a sensor base unit and extension modules. Background of the invention

[0002] To record industrial process variables, for example, in a chemical environment, it may be necessary for the sensor to be hermetically sealed. Self-contained sensors can be used for this purpose. Because these are enclosed in a sealed housing, they cannot easily be equipped with new functionalities, for example, by installing additional hardware. This makes it impossible, for example, to retrofit display and operating functions, data storage, or more powerful energy storage devices.

[0003] Accordingly, autonomously operating level sensors are developed specifically for a wide variety of customer requirements, resulting in a large number of sensor variants. This high number of different devices is a major disadvantage in terms of the resulting costs for development, approval, production, and distribution. Furthermore, the devices cannot be retrofitted with additional functions.

[0004] WO 2017 / 103887 A1 describes an aerosol dispensing device in which the control body is or can be coupled to a cartridge. US 2019 / 195717 A1 describes an inline sensor with a housing that can be mounted in a wall of a liquid line or a process container. US 2019 / 250019 A1 describes a modular kit for a field device with interchangeable components. EP 3015847 A1 describes a measuring device for measuring the density of fluid media with a density sensor, wherein measuring and sensor electronics are enclosed in a housing or a cartridge. EP 3349047 A1 describes a modular system for a radiometric measuring device, a base module with a sensor arrangement and an extension module, wherein the base module can be implemented on a first printed circuit board and the extension module on a second printed circuit board. DE 102015112536 A1 describes an optoelectronic plug-in module. Summary of the invention

[0005] It is therefore an object of the invention to propose a concept and devices according to the invention adapted thereto which eliminate the aforementioned disadvantages.

[0006] The object is solved by the subject matter of independent patent claim 1. Advantageous embodiments are the subject matter of the dependent claims, the following description, and the figures.

[0007] According to the invention, a sensor device with a sensor base unit for determining process variables in an industrial environment is provided. The sensor base unit has a first wireless communication unit configured to transmit signals to a first expansion module and / or receive signals from a first expansion module, as well as a first housing with a first receiving device configured to receive the first expansion module or a second housing, wherein the first housing completely encloses the sensor base unit.

[0008] The term "process automation in industrial environments" can be understood as a branch of technology that encompasses all measures for operating machines and systems without human intervention. One goal of process automation is to automate the interaction of individual components of a plant in the chemical, food, pharmaceutical, petroleum, paper, cement, shipping, or mining industries. A variety of sensors can be used for this purpose, each of which is specifically adapted to the specific requirements of the process industry, such as mechanical stability, insensitivity to contamination, extreme temperatures, and extreme pressures. Measured values ​​from these sensors are typically transmitted to a control room, where process parameters such as fill level, limit level, flow rate, pressure, or density can be monitored, and settings for the entire plant can be changed manually or automatically.

[0009] One sub-area of ​​process automation in the industrial environment concerns logistics automation. With the help of distance and angle sensors, processes within a building or within a single logistics facility are automated. Typical applications for logistics automation systems include baggage and freight handling at airports, traffic monitoring (toll systems), retail, parcel distribution, and building security (access control). What the above examples have in common is that the respective application requires presence detection in combination with precise measurement of the size and location of an object.

[0010] For this purpose, sensors based on optical measuring methods using lasers, LEDs, 2D cameras or 3D cameras that measure distances according to the time of flight (ToF) principle can be used.

[0011] Another sub-area of ​​process automation in the industrial environment concerns factory / production automation. Applications for this can be found in a wide variety of industries, such as automotive manufacturing, food production, the pharmaceutical industry, and packaging in general. The goal of factory automation is to automate the production of goods using machines, production lines, and / or robots, i.e., to run it without human intervention. The sensors used here and the specific requirements regarding measurement accuracy for detecting the position and size of an object are comparable to those in the previous example of logistics automation.

[0012] A "sensor" is a device that has a measuring sensor in a housing for determining the process variables, as well as the components present within the housing, such as electronic components, connections and mechanical elements.

[0013] The sensor base unit is designed, for example, to determine a pressure, a fill level, a limit level or a density as a process variable.

[0014] According to the invention, the sensor base unit is thus operated independently by the wireless communication unit and the wireless energy transmission unit, despite a closed housing around the sensor base unit. Due to the closed housing, all functional parts of the sensor base unit are located within the housing, i.e. in particular also the process variable acquisition unit including, for example, the electronics and usually also an antenna or a measuring sensor. The extension module can provide one or more extensions, as explained in the embodiments below. Thus, the sensor base unit or the sensor can be expanded as desired in a modular manner without interfering with the sensor base unit. Because only a mechanical receptacle is provided for connecting the sensor base unit to the extension module and no galvanic electrical connections with corresponding connecting devices, assembly is very simple.A wire or plug connection that may be subject to contamination, corrosion or deformation is not necessary.

[0015] The mechanical mount includes, for example, a thread, a snap-in mechanism, a click lock, a magnetic arrangement, or a hook-and-loop fastener. The thread can be, for example, an internal thread on a protruding edge of the housing, an external thread on the housing, or a central screw thread so that the expansion module can be screwed onto the housing of the sensor base unit.

[0016] According to one embodiment, the first housing hermetically encloses the sensor base unit, preventing any air or liquid from entering or escaping. Especially in cases where the housing must be hermetically sealed, it is important to minimize or avoid mechanical stress at external interfaces so that the seal is maintained. The proposed sensor base unit completely avoids such interfaces to the expansion module, i.e., cables, connectors, seals, etc.

[0017] According to one embodiment, the signals are measurement and / or control signals, and the first wireless communication unit is configured to send and / or receive the signals in analog or digital form. Typically, analog measurement signals are generated by a process variable determination unit in the sensor base unit, which are pre-processed and converted into digital signals and transmitted as digital data to the expansion module. The control, such as the measurement cycle, possible synchronization, configuration, data retrieval, etc., is carried out, for example, by a control unit of an expansion module. The control unit can receive the information, for example, from outside. The data can be modulated onto a carrier, for example, using a digital or analog modulation technique in accordance with a communication protocol. The communication protocol is preferably subject to a communication standard.

[0018] According to one embodiment, the sensor base unit, alternatively or in addition to the first wireless communication unit, has a first wireless energy transmission unit that is configured to send energy to the expansion module and / or receive energy from the expansion module. This means that energy transmission is possible in both directions. Thus, the expansion module can be a module without its own energy storage and can be supplied with energy from the sensor base unit, or vice versa. It is also possible, for example, for the energy to be transmitted in one direction at one time and in the other direction at another time, for example depending on excess or unneeded energy or on demand.

[0019] For power transfer or data acquisition, the housing does not need to be opened, and no sealed cable interface is required. The sensor base unit can have its own energy storage device, such as a battery, and receive additional power from an expansion module, thus preserving the battery and extending its service life. The optional energy storage device can also be rechargeable, or one that is only charged when energy is needed for a measurement or data transmission.

[0020] According to one embodiment, the first wireless energy transmission unit is configured to transmit and / or receive electrical energy inductively. Coils, for example, are considered as inductors; printed NFC antennas, for example, are also considered coils. Alternatively, the energy can be transmitted electroacously, for example, with the conversion from acoustic to electrical energy, or vice versa, taking place via a piezoelectric element, for example.

[0021] According to the invention, an expansion module for the sensor base unit for determining process variables in an industrial environment is further provided. The expansion module has a second wireless communication unit configured to transmit signals to the sensor base unit and / or receive signals from the sensor base unit, as well as a second housing with a second receiving device configured to match the first receiving device so that the expansion module can be received by the sensor base unit, wherein the second housing completely encloses the expansion module.

[0022] The mechanical mount of the extension module to be mounted on the sensor base unit is the counterpart to the mechanical mount of the sensor base unit and is therefore designed accordingly.

[0023] According to one embodiment, the second housing is configured to hermetically seal the expansion module. For example, the housing of the expansion module is designed mechanically and in terms of material to be waterproof, dustproof and / or airtight. Both the sensor base unit and the expansion module are thus configured to be able to operate independently, whereby independent can mean that the sensor base unit and the expansion module are both independent in themselves, or the combination of the sensor base unit with the expansion module due to the wireless connections, whereby, for example, the energy is distributed in the combination. According to a further embodiment, the signals that the second wireless communication unit of the expansion module sends or receives are measurement and / or control signals. Furthermore, the second wireless communication unit is configured to send and / or receive the signals in analog or digital form.The second wireless communication unit is thus designed to correspond to the first wireless communication unit of the sensor base unit with which the second wireless communication unit communicates.

[0024] According to one embodiment, the expansion module further comprises a second wireless energy transmission unit configured to transmit energy to the sensor base unit and / or receive energy from the sensor base unit. The second wireless energy transmission unit thus corresponds to the first wireless energy transmission unit of the sensor base unit, which accordingly receives or transmits the energy of the second wireless energy transmission unit. The energy is, for example, electrical or acoustic energy, and according to one embodiment, the energy transmission unit is configured to transmit and / or receive the electrical energy inductively or acoustically.

[0025] According to the invention, the second housing has a third receiving device that is configured to receive a further expansion module. The third receiving device can be different from the first, but is preferably designed the same, for example as a thread, a snap fastener, a click fastener, a magnetic arrangement, or a hook-and-loop fastener. The third receiving device allows a further expansion module to be connected to the sensor base unit via the first expansion module. Connected here means that this expansion module, which also has at least one wireless communication unit and optionally a wireless energy transmission unit, can send energy and / or signals to or receive from the sensor base unit.This means that any number of extension modules can be mounted as a stack of extension modules on the sensor base unit and connected to the sensor base unit for energy and signal transmission.

[0026] This allows for a variable, modular sensor configuration. The expansion modules can be configured to communicate with each other and, for example, provide power to another expansion module. An expansion module can be a final, i.e., top-level module to which no further expansion modules can be connected, such as a display and control module, where the display and control units must be accessible to a user.

[0027] As described below, the expansion modules have different assemblies, components, interfaces, functionalities, etc. Although specific embodiments are presented below, an expansion module can also have a combination of different module types of the following embodiments or parts thereof.

[0028] According to one embodiment, the expansion module is configured as an energy module having at least one energy storage device. For example, the energy module contains one or more batteries as energy storage devices. This allows the sensor base unit to be supplied with sufficient energy. The module can also have a circuit that detects when the energy supply is running low and a display that indicates this status. If the sensor device furthermore has an external communication unit, the status can be transmitted, for example, to a server or a smartphone, and the energy module can be easily replaced when required, without the sensor base unit and / or the energy module having to be opened, and without the sensor base unit having to be removed for maintenance.If the expansion module is an intermediate module between the sensor base unit and another expansion module, the expansion module can be configured to transfer energy to the other expansion module. Furthermore, the energy storage device can be a rechargeable energy storage device, allowing the expansion module to receive, store, and release energy from the sensor base module or another expansion module.

[0029] According to one embodiment, the extension module is configured as an external communication module and includes a third communication unit. External communication can be implemented, for example, according to one or more of the following standards: Wi-Fi, 5G, Bluetooth, Zigbee, NB-IOT, GSM, CAT-M, LoRa, Sigfox, or other data transmission protocols. The communication unit can also support a wired connection, e.g., a fieldbus connection, and the extension module can provide the corresponding hardware and software, such as a corresponding plug-in connection or other connection.

[0030] According to one embodiment, the expansion module is configured as a service module and has a data memory and a memory processing unit. The memory processing unit is configured to store data received at the second communication unit and to manage the memory. Measurement data can thus be stored over a longer period of time. The data memory can be a built-in or removable memory. In the case of a built-in memory, the memory can be transmitted, for example, via a further wireless communication unit to a communication unit outside the expansion module, e.g., a server or a smartphone. The data can also be transmitted, for example, to an expansion module configured as an external communication module in order to transmit the data, e.g., to a network or a smartphone.

[0031] According to one embodiment, the extension module is configured as an adapter module and has an adapter unit configured to accommodate a wired additional sensor module and to convert the wireless communication with the sensor base unit and / or wireless energy transmission from or to the sensor base unit into wired communication with the sensor base unit or into wired energy transmission from or to the sensor base unit. Thus, an existing additional sensor module, which may have similar properties to the extension modules presented here, except for the housing, and which operates in a contactless manner, can simply be inserted into the extension adapter, for example. Using an extension adapter, a conventional, contactless sensor module can therefore also be used if the sensor base unit does not have any contactless interfaces suitable for the additional sensor module.

[0032] According to a further embodiment, the expansion module is configured as a cable module and has an interface for wired external communication and / or external power supply. The cable module can thus be connected to an external DC or AC voltage source via a wired connection to provide power for the sensor base unit or another expansion module.

[0033] According to the invention, a sensor device is provided which comprises a sensor base unit as described above and an expansion module as described above, wherein the expansion module is mounted on the sensor base unit. According to the invention, a further expansion module is mounted on the expansion module.

[0034] Thus, virtually any number of expansion modules can be connected to the sensor base unit. This provides a sensor device for determining process variables with a sensor base unit, wherein the sensor device can be modularly expanded by one or more stackable expansion modules. According to one embodiment, the first expansion module is attached to one side of the sensor base unit and is configured to receive the second expansion module as the final expansion module or to form a stack of further expansion modules. For example, the first expansion module is attached to the top side of the sensor base unit and the second expansion module to the top side of the first expansion module, so that a stack of expansion modules is built up that extends perpendicular to the surface of the sensor base unit. In this case, the communication interfaces of the first expansion module are located on opposite sides, e.g.Top and bottom. If the expansion modules are cylindrical, stacking them creates a cylindrical stack with a round cross-sectional area, where the total height is determined by the height of the individual expansion modules. The individual expansion modules can have the same or different heights. A final expansion module does not necessarily have to have two mechanical or communication interfaces. For example, if the final expansion module is a display and control unit, another expansion module could potentially hinder or prevent reading the display or operating the sensor device.

[0035] Other types of expansion modules include a sensor module, which can include an acceleration sensor, a pressure sensor, a geomagnetic field sensor, a gas sensor, a distance sensor, a brightness sensor, and / or a temperature sensor. Distance sensors such as lidar, radar, and ultrasound, as well as motion sensors and brightness sensors, are particularly suitable for use in the final expansion modules.

[0036] Other variations of the disclosed embodiments may be understood and practiced by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that particular measures are recited in dependent claims does not mean that a combination of those measures cannot be advantageously used. Reference signs in the claims should not be construed to limit the scope of the claims. Short description of the characters

[0037] In the following, embodiments of the invention are described in detail with reference to the accompanying figures. Neither the description nor the figures are intended to be construed as limiting the invention. The same reference numerals in different figures denote the same components, unless expressly stated otherwise. Fig. 1 a diagram of a self-contained sensor, Fig. 2 a diagram of a sensor with integrated on-site display, Fig. 3 a diagram of a sensor with a photovoltaic module, Fig. 4 a diagram of a sensor device with a sensor base unit and an extension module, Fig. 5 Diagrams of various extension modules, Fig. 6 a diagram of a mechanical mount for an expansion module with an angle indicator unit, Fig. 7 a diagram showing the inventive arrangement of a sensor base unit and a stack of expansion modules. Detailed description of the characters

[0038] Fig. 1 to Fig. 3 show examples of typical sensors that cannot be retrofitted with additional functions.

[0039] Fig. 1 shows a sensor 101 comprising a battery 102, a wireless communication module 103, and a fill level detection unit 104. For maintenance and on-site operation, the sensor 101 also comprises a near-field communication unit 105, for example, an NFC unit or a Bluetooth unit. The interaction of the illustrated components allows for the realization of a self-sufficient measuring system.

[0040] Fig. 2shows an alternative embodiment of a sensor 201 with an integrated on-site display, for example, an LCD unit 202 or an e-paper unit 202 with an operating function. In this embodiment, the near-field communication unit 105 can also be omitted, since the display and / or operation of the sensor are provided directly with the aid of the unit 202.

[0041] In the Fig. 1 and Fig. 2 For the sensors shown, the complete sensor unit 101, 201 must be replaced and disposed of after the battery 102 has been discharged. Fig. 3301 shows a version of a sensor 301 enhanced with an energy harvesting option 302, for example, a photovoltaic module 302. The sensor 301 is capable of collecting energy during sunny days and storing it in the accumulator 303. During less sunny times, this energy can then be used to maintain the measurement before the battery 302 has to be used for measurement in the event of an energy deficit. This allows the lifetime of the sensor to be greatly increased with the arrangement 301. However, the manufacturing costs of the sensor 301 are significantly higher than those of the sensor 101.

[0042] Fig. 4 shows an example of a level sensor 401 as a sensor base unit 401, which essentially consists of the components already described in Fig. 1shown parts: battery 102, wireless communication unit 104, and level detection unit 104, which, in interaction, can realize an autonomous level measurement. The hermetically sealed housing of the sensor 401, however, has on its outside a mechanically designed receiving device 408 or contour 408, which is suitable for receiving an expansion module 403, here a display module 403 with a matching contour 417. The expansion module 403 is also hermetically sealed and thus easily protected against external influences. The wireless energy transmission units 103, 405 serve to exchange energy between the autonomous level sensor 401 and the expansion module 403. Typical units are used here, for example inductively coupling units or RFID standards such as NFC.In addition, the sensor 401 and the expansion module 403 each have at least one wireless communication unit 402, 406, which is configured to exchange control commands and / or data. Applicable state-of-the-art standards include Bluetooth, Zigbee, RFID, NFC, or capacitive technologies for bidirectional coupling or optical methods.

[0043] The presented ensemble of autonomous level sensor 401 and extension module 403 enables in the example of Fig. 4 to equip a standard sensor 401 with an additional display 404 either subsequently or ex works.

[0044] The principle of extending a basic sensor 401 with additional modules 501, 502, 503, 504, 505, 522 is described in Fig. 5 further refined. All examples shown have a power transmission unit 405 and a communication unit 406 in common.

[0045] The energy module 501 includes one or more energy storage devices 506, which are suitable for providing additional energy to a base sensor 401 and thus increasing its service life.

[0046] The user interface module 502 is equipped to enable on-site operation of the base sensor 401 with the aid of a display unit 511 and / or an input unit 512.

[0047] The communication module 503 is suitable for expanding the base sensor 401 with additional wireless communication standards, for example, with various low-power standards such as LoRa, Sigfox, LPWAN, or with other standards such as WLAN, GSM, and 5G. For this purpose, the expansion module 503 has at least one communication chip 507 and an antenna 508. Depending on the design, additional energy storage devices 509 or energy buffers 510 are also used to provide high power for short periods of time.

[0048] The service module 504 can be used to create long-term recordings of operationally relevant data of a base sensor 401, for example using permanently installed or replaceable memory modules 513.

[0049] The adapter module 505 converts the energy and information wirelessly transmitted from the base sensor into a wired form and makes it available at an interface 514. This interface for attaching wired add-on modules can be a standard interface and enables the transition to common, existing add-on modules. The wired add-on module 515 is hermetically protected from environmental influences by a cover 516 of the adapter module 505.

[0050] Finally, the cable module 522 can be used whenever a standalone base sensor 401 is to be subsequently supplied and / or evaluated via a wired connection. For this purpose, the cable module 522 provides at least one interface 517 for connecting a cable 518, which can transmit additional power to the sensor 401 and / or read information such as measured values, software updates, etc. from the sensor or input information into it from the outside.

[0051] The examples of Fig. 5 also show different examples of mechanical contours 417, 519, 520, 521 for fastening the extension module to the base sensor 401. The use of threaded contours 519, snap-on contours 520 or magnetic contours 521 or Velcro contours 521 is conceivable here. It can also be provided that the Fig. 4The gap 409 shown between the base sensor 401 and the extension module 403 is to be sealed against dirt and moisture penetration by installing a seal in the extension module.

[0052] Fig. 6shows a further development of the contours 407, 519, 520, 521. To construct particularly small, efficient coupling elements 402, 103, 406, 405, it is necessary for the energy transmission modules 103, 405 and / or the communication modules 402, 406 to be substantially opposite one another after the expansion module 403 has been attached. This increases the efficiency of energy and / or data transmission. For this reason, the expansion module 403 has an angle indicator unit 601, for example, a pin 601, which engages in the groove 604 during the assembly of the expansion module 403 on the base sensor 401. The groove, with its end point 602, in interaction with the angle indicator 601, forms an angle positioning unit which ensures that the mounting angle 603 between the base sensor 401 and the extension module 403 corresponds to a predefined target angle 603.

[0053] At this point, the person skilled in the art is aware of further mechanical devices which can ensure a predefined angular position after assembly.

[0054] Fig. 7 shows an inventive embodiment of the sensor device 400 with the extension modules 701, 702, 703, with which a stacking of several modules is achieved.

[0055] This allows the sensor base unit 401 to be expanded with multiple functions, whereby intermediate modules 701, 702 can also be used as final expansion modules or end modules 703. In particular, energy modules 501, communication modules 503, service modules 504, or even cable modules 522 can be used as intermediate modules. Intermediate modules 701, 702 are characterized in that they have mechanical receptacles 704 for attaching additional expansion modules, but also have suitable communication units 705 and / or energy transmission units 706, which serve to connect additional expansion modules.

[0056] In principle, all extension modules presented so far can be used as end modules 703, in particular also the intermediate modules 701, 702. It is obvious that modules with photovoltaic elements or display and control elements in particular are primarily designed as end modules 703.

Claims

1. A sensor device (400), comprising a self-sufficient sensor base unit (401) for determining process variables in an industrial environment and at least one first expansion module (403), which can be attached to the sensor base unit (401), and a further expansion module; wherein the self-sufficient sensor base unit (401) comprises: a first wireless communication unit (402), configured both to transmit signals to the first expansion module (701) and / or receive signals from the first expansion module (701) and to transmit signals to the further expansion module (702, 703) and / or to receive signals from the further expansion module (702) and / or a first wireless power transmission unit (103), configured both to transmit power to the first expansion module (701) and / or to receive power from the first expansion module (701) and to transmit power to the further expansion module (702, 703) and / or to receive power from the further expansion module (702, 703); a first housing with a first receiving device (407), configured to receive the first expansion module (701), wherein the first housing completely encloses the sensor base unit (401); and wherein the first expansion module (701) comprises: a second wireless communication unit (406) configured to transmit signals to the sensor base unit (401) and / or receive signals from the sensor base unit (401); and a second housing having a second receiving device (417) configured to match the first receiving device (407) so that the first expansion module (403) can be received by the sensor base unit (401), and a third receiving device for receiving the further expansion module, wherein the second housing completely encloses the first expansion module (701); and whereby the further expansion module comprises: a third wireless communication unit configured to transmit signals to the sensor base unit and / or receive signals from the sensor base unit; and a third housing with a further receiving device, which is designed to match the third receiving device (704), so that the further expansion module can be received by the first expansion module, wherein the third housing completely encloses the further expansion module; and wherein the first expansion module and the further expansion module have different assemblies, components, interfaces and / or functionalities.

2. The sensor device (400) according to claim 1, wherein the first housing hermetically encloses the sensor base unit (401).

3. The sensor device (400) according to claim 1 or 2, wherein the signals are measurement and / or control signals, and the first wireless communication unit (402) is configured to transmit and / or receive the signals in analogue or digital form.

4. The sensor device (400) according to any one of the preceding claims, wherein the first wireless energy transmission unit (103) is configured to transmit electrical energy inductively or electroacoustically.

5. The sensor device (400) according to any one of claims 1-3, wherein the first wireless energy transmission unit (103) is configured to receive electrical energy inductively or electroacoustically.

6. The sensor device (400) according to any one of the preceding claims, wherein the second housing (421) hermetically encloses the first expansion module (701).

7. The sensor device (400) according to one of the preceding claims, wherein the signals are measurement and / or control signals, and the second wireless communication unit (406) is configured to transmit and / or receive the signals in analogue or digital form.

8. The sensor device (400) according to one of the preceding claims, wherein the first expansion module (701) or the second expansion module (702, 703) further comprises a second wireless power transmission unit (405) configured to transmit power to the sensor base unit (401) and / or receive power from the sensor base unit (401).

9. The sensor device (400) according to claim 8, wherein the second wireless energy transmission unit (405) is configured to transmit and / or receive electrical energy inductively.

10. The sensor device (400) according to one of the preceding claims, wherein the first expansion module (701) or second expansion module (702, 703) is an energy module (501) and has at least one energy store (506); or is a display and / or operating module (502) and has a display (511) and / or operating unit (512); or is an external communication module (503) and has a third communication unit (507); or is a service module (504) and comprises a data memory (513) and a memory processing unit, wherein the memory processing unit is configured to store data received at the second communication unit (406) and to manage the data memory (513); or is an adapter module (505) and comprises an adapter unit (516) which is configured to receive a wired sensor add-on module (515) and to convert the wireless communication with the sensor base unit (401) and / or wireless energy transmission from or to the sensor base unit (401) into a wired communication with the sensor base unit (401) or into a wired energy transmission from or to the sensor base unit (401); or is a cable module (522) and comprises an interface (518) for wired external communication and / or external power supply.