ADAPTER FOR REMOTE MAINTENANCE OF A CONTROL UNIT WITH A DISPLAY UNIT

Description

[0001] The invention relates to an adapter for coupling a control device having a display unit to a communication network and to an adapter system having at least one adapter and one communication unit.

[0002] Industrial plants with control systems often have the capability to be maintained remotely. For this purpose, the control systems are typically linked to a communications network. It is also known that such remote access requires proprietary protocols and encrypted connections known only to the manufacturer. This can be costly for the operator of the industrial plant, as remote maintenance tasks cannot be performed directly by the operator, and the manufacturer charges for these services.

[0003] The documents US 6 081 856 A, US 2004 / 024840 A1, EP 0 387 359 A1 and DE 10 2015 114627 A1 relate to solutions for computers that can be used for control or control devices in which a video stream can be sent to external components via the connected network by means of a built-in component, such as a network card or a modem.

[0004] The object of the present invention is to provide a device or a system that enables rapid and cost-effective remote access without making complex modifications to the control system.

[0005] This object is achieved according to the invention by an adapter for coupling a control device having a display unit with the features specified in claim 1. Advantageous embodiments of the adapter emerge from the subclaims, the following description and the drawings, wherein the features specified in the subclaims and the description are applicable individually but also in suitable combination.

[0006] The adapter according to the invention for coupling a control unit having a display unit to a communication network comprises a carrier with a first connector for connecting the adapter to a display connection of the control unit, a second connector electrically connected to the first connector for passing received signals from the first connector to the second connector, a processor unit, and a data interface, wherein the first connector and the second connector are designed to be mechanically complementary to one another, wherein the processor unit is coupled to the first connector and the data interface and is designed to convert control signals received from the first connector, which are provided for controlling a display unit, into a data set or a data stream and to pass them to the data interface, and wherein the data interface is designed toto transfer the data set or data stream to an external communication unit.

[0007] The adapter according to the invention can realize remote access with virtually no modification of the control unit in question. It is assumed that the control unit in question comprises a circuit board to which a display unit and preferably an input unit are provided. In a particularly simple case, the adapter is designed to additionally provide information displayed to a user locally on the display unit for transmission at the data interface.

[0008] The display unit could feature a display selected from a wide variety of options. In addition to simple status LEDs or 7-segment displays, matrix displays of various sizes may also be available. Such display units are typically largely standardized and include a plug-in connector with several spaced-apart pins in one or more rows. The control unit's circuit board has a corresponding display connector for connecting to the display unit, into which the display unit's pins are plugged.

[0009] Depending on the industrial plant, the control unit can perform various tasks and, as required, present information to the user on the display unit, depending on the design of the control unit. An input unit with buttons and / or switches can be provided for making inputs to the control unit. It is therefore conceivable for a user to check various operating parameters on-site at the control unit using the display unit and, if necessary, change them using the input unit. For this purpose, the control unit could display a menu or other user guidance on the display unit, and the user can use the input unit to navigate to the desired operating parameters and display and / or change them.

[0010] The adapter according to the invention utilizes the provided connection between the display unit and the circuit board to receive the control signals transmitted to the display unit. For this purpose, the first connector is designed like a plug-in connection of the display unit, so that it can be plugged directly into a display connection of the control unit or the circuit board of the control unit. Since the second connector is designed to be complementary to the first connector, it largely corresponds to the display connection of the control unit. Since it is also arranged on an opposite side of the adapter, the display unit can be plugged into the second connector when the adapter is connected to the display connection. The first connector transmits the received signals directly and completely to the second connector, so that the function of the display unit is fully retained.

[0011] The processor unit is coupled to the first connector. Consequently, the processor can receive and process control signals for the display unit, or signals or data derived therefrom, directly or via an intermediary device. The design of the control signals depends on the design of the intended display unit. The goal is to provide data or a data stream from the control signals that can be transmitted to a communication unit via the data interface in order to be able to use standardized protocols, encryption methods, or similar.

[0012] The processor unit could be designed to directly evaluate the control signals. In addition to analog variants, digital control signals are also conceivable. If analog control signals are used, it is conceivable that the processor unit comprises or is connected to one or more voltage sensors, wherein the voltage sensors are capable of detecting voltages for the individual pins of the display unit and, from this, determining the display triggered by the control signals. It is also conceivable to use an upstream device that is directly connected to the first connector and sends data dependent on the control signals to the processor unit, which then determines the display. For the implementation of the adapter according to the invention, individual adaptation to the control signals is expedient. The processor unit could be adapted via software in order to be able to evaluate a wide variety of signals or data.

[0013] The processor unit is therefore capable of generating a transmittable data set or data stream from abstract control signals for a display unit, which can be transmitted externally via the data interface. A suitable communications unit can then receive the data delivered at the data interface and, in particular, transmit it to an operator of the industrial plant via standardized communication methods. Consequently, the adapter is capable of providing remote access for a control unit of an industrial plant with virtually no modifications.

[0014] In an advantageous embodiment, the carrier comprises a circuit board, wherein the first connector and the second connector are arranged congruently on a bottom and a top side of the carrier. The circuit board of the adapter is preferably adapted to a display board of the display unit, if the display unit has one. The display unit of the control unit can thus be easily replaced with the adapter, in order to then plug the display unit removed from the control unit onto the adapter. The term "congruently" is to be understood as meaning that both connectors overlap or are arranged one on top of the other in a plan view of a top or bottom side of the circuit board. It is conceivable that the first connector has a row of pins that can be plugged into a display connection of the control unit. The second connector could comprise a row of recesses and contact springs for receiving and contacting pins.The second connector could comprise several pins for contacting the adapter's circuit boards, which are then soldered together. These pins could be dimensioned such that, when the second connector is plugged in and soldered, they extend far enough through the carrier to the opposite side that they themselves constitute the first connector. The first and second connectors could therefore also be constructed as a single piece. This additionally ensures that control signals from the control unit are routed directly from the first connector to the second connector.

[0015] In an advantageous embodiment, the data interface is an optical data interface. By using an optical data interface, a communication unit can be completely electrically or galvanically separated from the adapter. Standardized cables and connectors with different shapes and contact surfaces can be used to connect the optical data interface to a communication unit.

[0016] In an advantageous embodiment, the adapter further comprises a pilot control configured to receive the control signals and decode them into an image intended for the display unit. The decoding of the control signals depends on the type of display unit provided as well as the control signals themselves. It is conceivable for the display unit to be digitally controlled via a data bus, for example a 4- or 8-bit data bus. The display contained in the display unit can be controlled, in particular, via a driver module integrated into the display unit, which converts the signals transmitted via the data bus into direct control voltages for individual cells of the display. The effort required to connect a display unit to the control unit is thus minimized, and a wide variety of display units with such control via a data bus are commercially available.The feedforward control enables the adapter to simulate an image to be displayed on the display unit in a manner tailored to the display unit in use. The signals via the data bus or other control signals are then converted to create an image that is displayed on the display unit. The feedforward control can therefore function similarly to a driver module and have rules that are necessary for the conversion. The feedforward control can comprise an interface that can be coupled to the first connector to receive the control signals and feed them for further processing. The feedforward control can be a separate unit. The feedforward control could also be part of the processor unit. The feedforward control interface could be integrated into the processor unit or implemented as a separate component.

[0017] In an advantageous embodiment, the processor has a text recognition unit configured to convert the output of the feedforward control into text information. Consequently, the abstract image is subjected to text recognition to determine the characters contained in the image and their arrangement. This is useful for reducing the size of the information to be transmitted. This could, among other things, enable data transmission even at low bandwidths.

[0018] In an advantageous embodiment, the processor has a content recognition unit designed to recognize specific expressions in the text information. Since simple text recognition is only sufficient for the automated interpretation of the content of the image in exceptional cases, for example when only a single character is displayed, it is particularly useful to also interpret the recognized text logically. The control unit in question could include a static menu structure with a fixed set of parameters. Information about the static menu structure and the individual parameters could be stored in a memory of the information recognition unit. The content recognition unit could therefore search the text information of the image for known expressions stored in this memory.This enables the content recognition unit to identify which information, parameters, values, and the like are contained on a current display of the display unit. This makes it possible to collect information that goes beyond pure image representation and is also independent of direct operation of the control unit by the user. A user therefore does not have to capture and interpret information on a current display themselves; this can be done by the content recognition unit. This could simplify remote maintenance, because the interface of a remote maintenance program could clearly display various adjustable parameters or other information that is pre-populated with recognized content supplied by the content recognition unit. As shown below, the content recognition unit also allows automatic navigation through a menu structure.

[0019] In an advantageous embodiment, the adapter further comprises an instruction unit coupled to the processor and connectable to terminals of an input unit of the control unit. For example, several buttons are provided on the control unit, each bridging two contacts on a circuit board. The button connections could be tapped at solder points and fed to the instruction unit. The arrangement and labeling of the physical buttons of the control unit could be reproduced in a remote maintenance program. A user could then operate the corresponding buttons on a user interface, which is transmitted to the adapter and implemented by the instruction unit on the control unit. In a simple case, the instruction unit is designed to bridge contacts, for example, using relays or semiconductor switches.

[0020] In an advantageous embodiment, the instruction unit is configured to generate electrical signals to simulate manual inputs into the input unit. The instruction unit thus generates signals that are passed to the input unit of the control unit to simulate user inputs on-site. This could be conceivable for more complex input units, for example, those with a keypad connected to the control unit via a proprietary or standardized interface. The instruction unit is then configured to produce corresponding data or signals.

[0021] In an advantageous embodiment, the processor has a parameter change unit that is coupled to the instruction unit and is designed to automatically retrieve, using the instruction unit, parameters that can be changed one after the other from the control unit and / or to change parameters specified by a user using the instruction unit in the control unit through targeted inputs. The parameter change unit can be used to further automate remote maintenance. The control unit could, for example, be designed to generate several different displays that can be cycled through by pressing keys on the input unit in order to display various parameters on the various displays. Other keystrokes could be provided to change the respectively displayed parameters, for example, to incrementally increase or decrease them.The parameter change unit can have knowledge of such a menu structure, the parameters to be changed, and other information via a memory. Through coupling with the instruction unit, the parameter change unit could cause the instruction unit to independently switch to a desired display by generating inputs, in order to forward the displayed information there for further processing. In a first operating mode, the parameter change unit could retrieve all parameters and information from the control unit, for example, by scanning through and processing all possible, intended displays. The parameters and information could be recognized and transmitted by the content recognition unit to then fill in the corresponding fields or graphics of a remote maintenance program.In a second operating mode, a user's parameter change requests could be automatically implemented by the parameter change unit. To do this, the unit could select a relevant display and then set the parameters via the instruction unit by simulating keystrokes.

[0022] The invention further relates to a remote maintenance system comprising at least one adapter according to one of the preceding claims and a communication unit, wherein the at least one adapter is connectable to the communication unit.

[0023] In an advantageous embodiment, the communication unit is a data network device.

[0024] In an advantageous embodiment, the communication unit has a plurality of adapter connections so that a plurality of the previously described adapters can be signal-connected to the communication unit, so that a parallel data exchange with a plurality of control units, each with at least one adapter, is enabled via the one communication unit.

[0025] In an advantageous embodiment, the at least one adapter and the communication unit are designed to form a galvanically isolated connection to one another. Data exchange between the adapter and the communication unit preferably takes place optically via one or more optical fibers.

[0026] The invention further relates to a method for coupling a control device having a display unit to a communication network, comprising the steps: Uncoupling the display unit (6) from a display connection (4) of the control unit (60), connecting a first connector (18) of an adapter (14) to the display connection (4) of the control unit (60), converting control signals received via the first connector (18), which are originally intended to control the uncoupled display unit (6), in the adapter (14) into a data set or a data stream, transmitting the data set or the data stream to an external communication unit (36) which is signal-connected to the communication network.

[0027] Optionally, the method may further comprise the following steps: Connecting the decoupled display unit (6) to a second connector (26) of the adapter (14) which is mechanically complementary to the first connector (18), and displaying data by means of the display unit (6) in accordance with the received control signals.

[0028] Optionally, the method may further comprise the following steps: Connecting an instruction unit (56) of the adapter (14) to terminals of an input unit (62) of the control unit (60), and simulating manual inputs into the input unit (62) of the control unit (60) by means of the instruction unit (56) of the adapter (14).

[0029] The invention is explained in more detail below with reference to an embodiment illustrated in the drawings. They show: Fig. 1 shows a circuit board of the control unit in a top view; Fig. 2 shows a display unit on the circuit board; Fig. 3 shows an adapter and the display unit located thereon on the circuit board; Fig. 4 shows a schematic illustration of the principle of how the adapter is functionally interposed between the display unit and the circuit board of the control unit; Fig. 5a and 5b show a schematic illustration of how the adapter is spatially interposed between the display unit and the circuit board of the control unit; Fig. 6a and 6b show the display unit in two different views; Fig. 7 and 8 show the adapter in two different views; Fig. 9 shows a communication unit connected to the adapter; Fig. 10 shows a schematic, block- and function-based representation of the adapter; Fig. 11 shows an overall view of a system comprising the control unit, adapter, input unit, the display unit, communication unit, and a remote maintenance system; and Fig.12The system consisting of the control unit, adapter, input unit, display unit, and communication unit in a block-based representation.

[0030] Fig. 1 shows, by way of example, a circuit board 2 of a control unit to which remote access is desired. Here, a display connection 4 in the form of a pin connector strip is provided for accommodating a display unit 6. The display unit 6 is located on the display connection 4. This display unit is intended to display various information and receives control signals from the circuit board 2 for this purpose. The other functions of the circuit board 2 are irrelevant for the following description of the invention.

[0031] In Fig. 2 The circuit board 2 is shown in a three-dimensional view. Here, the display connector 4 of the circuit board 2 can be seen, into which a row of pins 8 of the display unit 6 are plugged. The display unit 6 has a display board 10, which is screwed to the circuit board 2 via spacers 12, for example.

[0032] As in Fig. 3 shown, according to the invention, an adapter 14 is inserted between the display board 10 and the circuit board 2 in order to generate a data set or a data stream from control signals from the display connection 4, which are fed to the display unit 6, and to make it available at a data interface. For this purpose, the adapter 14 has a first connector 18, which is designed to match the display connection 4 and thus at least largely corresponds to the arrangement of pins 8 of the display unit 6. The first connector 18 is arranged on a carrier 20, which is in the form of a circuit board, and extends from an underside 22 of the carrier 20. On an opposite upper side 24, a second connector 26 is arranged, which is designed to be complementary to the first connector 20 and thus essentially corresponds to the display connection 4.Control signals provided at the display terminal 4 for the display unit 6 are thus routed directly to the second connector 26. The display unit 6 is plugged onto the second connector 26, so that it converts the control signals to display information.

[0033] In this exemplary embodiment, the carrier 20 is designed to correspond in size to the display board 10. Consequently, the adapter 14 can be arranged at the intended location of the display unit 6. The attached display unit 6 only results in a slight increase in installation space at this location. It is conceivable to design the adapter 14 such that the display unit 6 can be screwed to the adapter 14 using suitable spacers.

[0034] The data interface 16 is embodied here as an optical data interface, which does not require a direct electrical connection between the adapter 14 and a communication unit. Optical conductors 28 are fed to the communication unit 36 and provide the data set or data stream. The communication unit 36 is then galvanically isolated from the adapter 14.

[0035] Fig. 4 The functional interconnection between the circuit board 2, the adapter 14, and the display unit 6 is shown schematically. Normally, the display unit 6 is plugged directly onto the display connection 4 of the circuit board 2. According to the invention, however, the display unit 6 is decoupled from the display connection 4 of the circuit board 2 in order to insert the adapter 14 in between. The adapter 14 is plugged onto the display connection 4 of the circuit board 2 with the pins of its first lower-side connector 18, and the display unit 6 is plugged onto the second upper-side connector 24 of the adapter 14. Fig. 5a,b the spatial arrangement becomes clearer as a stack of parallel boards.

[0036] In Fig. 6a und 6b The display unit 6 is shown in a separate illustration. The display board 10 has four mounting holes 30 for connecting to the spacers 12. The pins 8 are arranged in a single row and located at an edge area of the display board 10. For example, a liquid crystal display 32, which is designed as a matrix display, is located on the top side of the display unit 6.

[0037] Fig. 6b shows an underside of the display unit 6. Various electronic components are arranged here, which serve to convert control signals and to convert and / or stabilize a supply voltage.

[0038] Fig. 7 shows a spatial view of the adapter 14 from above, while Fig. 8 shows the adapter 14 from below. Here, the optical conductors 28 are connected to the data interface 16 and lead to the Fig. 10 shown communication unit 36. A processor unit 34 is arranged on the carrier 20. This is coupled to the first connector 18 and the data interface 16 and is designed to receive control signals from the circuit board 2 of the control unit directly or in the form of processed signals or data and to provide them as a data set or data stream to the data interface 16. To operate the adapter 14, a voltage can be used which is present at the first connector 18 and serves to supply the display unit 6 with a voltage. Fig. 7 It is also clear that the first connector 18 and the second connector 26 are arranged congruently on the carrier 20.

[0039] Fig. 9 shows a communication unit 36 having a plurality of connections 38 for optical conductors 28. Additionally, a network connection 40 is provided, into which a data connection cable, for example a network cable with an RJ45 connector, can be plugged and connected to a modem, a router, a firewall, or the like. The communication unit 36 therefore represents a type of network card. In the exemplary embodiment shown, a special feature is that the communication unit 36 has a plurality of connections 38, which enable a connection to a plurality of adapters 14. More complex industrial systems are conceivable, for example, which have a plurality of control devices, each provided with its own adapter 14. These can be coupled to the communication unit 36 in order to be connected to a user via a corresponding data network.The communication unit 36 is preferably galvanically isolated from the adapters 14, which in this example is achieved by using optical conductors 28. It is particularly advantageous to supply the communication unit 36 with its own power supply.

[0040] Fig. 10 shows an embodiment of the adapter 14 in a schematic, block- and function-based representation. The adapter 14 monitors a display bus. A trigger 41 detects whether and when control signals are sent to the display unit 6, and an instruction buffer 39 is filled with instructions in the form of control signals. The instructions are temporarily stored in the instruction buffer 39 and successively fed to a pre-control 42, which can process them gradually. The pre-control 42 is designed to decode the instructions in the form of control signals and thus emulate the behavior of the display unit 6. The pre-control 42 thus provides a type of virtual display unit that is adapted to the specific display unit 6 by appropriate rules or algorithms.If, for example, the display unit 6 is a matrix display and the name of a submenu or a parameter is displayed thereon, the feedforward control 42 can consequently create a type of image with image information of the individual pixels of the matrix display.

[0041] The output of the feedforward control 42 can be stored in a buffer 44. In this example, the processor unit 34 can retrieve the data from the buffer 44 and convert it into text information. This is achieved by a text recognition unit 46, which recognizes text contained in the image information, similar to an OCR analysis. As a result, instead of a pixel-based image of the display unit 6, only text information is generated, which significantly reduces the bandwidth required for data transmission to a user who remotely maintains the control unit.

[0042] A corresponding data set or data stream with text information can be sent to the data interface 16, from where the data set or data stream can be fed to an external communication unit 36.

[0043] In this example, it is also possible to derive logical links from the text information. This is achieved by a content recognition unit 50, which recognizes certain expressions and parameter names, for example, using search patterns. Expected expressions and / or parameter names could be stored in a database and compared with text information. This enables the content recognition unit 50 to automatically read various parameters from the control unit and store them in a parameter storage unit 52.

[0044] To enable a user and / or the content recognition unit to not only capture static content on display unit 6, but also select or change individual parameters, a remote maintenance logic unit 54 is provided. This logic unit has knowledge of the control unit's user interface structure and is capable of locating and, if necessary, changing a parameter desired by a user. For implementation, remote maintenance logic unit 54 is coupled to an instruction unit 56. This instruction unit can implement specific instructions desired by the remote maintenance logic unit. Instruction unit 56 can be connected to circuit board 2 of the control unit via individual lines. Circuit board 2 could, for example, include connections for individual buttons and / or switches, or buttons and / or switches could be soldered directly onto circuit board 2. Instruction unit 56 can be connected to the corresponding connections or solder points.The instruction unit 56 simulates individual key presses and passes them directly to the circuit board 2 so that commands can be transmitted to the circuit board 2.

[0045] Additionally, a parameter change unit 58 can be provided, which can be used for the automated reading and / or changing of parameters. This eliminates the need for real-time control of the control unit's menu, where a user works through individual menu items or parameters. Instead, a user can enter desired parameters on a control computer and transmit them to the parameter change unit 58, which automatically navigates to the relevant menu items and changes the parameters as desired. For this purpose, the parameter change unit 58 is coupled to the remote maintenance logic unit 54, the content recognition unit 50, the parameter storage unit, the communication unit 36, and additionally—in addition to the indirect coupling via the remote maintenance logic unit 54—directly to the instruction unit 56. The communication unit 36 is signal-connected to a communication network via a bus interface 59 or a direct connection.

[0046] For the instruction unit 56 and the parameter change unit 58, it is assumed that the structure of the input unit, i.e., the buttons and / or switches, as well as their effects on the control unit, are fully known and stored in the form of appropriate logic. For example, buttons could be provided that incrementally increase or decrease a parameter, while other buttons are provided for scrolling up or down through a menu list.

[0047] Fig. 11 shows a schematic overall view of a system comprising several control units 60, each with an adapter 14, an input unit 62, and the display unit 6, the common communication unit 36, and a possible remote maintenance system 64 for operation by a user 66. This may include a control computer 68 for performing inputs, which sends these data, for example, to a remote maintenance control unit 70. This could provide a user interface suitable for remote maintenance, so that the control computer shown can access it simply via a data connection and does not need to be fully prepared for control. The remote maintenance control unit 70 can be connected to a server 72.

[0048] For the sake of completeness, Fig. 12 a single system consisting of a control unit 60, an adapter 14, a display unit 6, an input unit 62 and a communication unit 36 is shown. Bezugszeichenliste

[0049] 2 Control unit circuit board 4 Display connector 6 Display unit 8-pin 10 Display board 12 Spacer 14 Adapter 16 Data interface 18 First connector 20 Support 22 Bottom 24 Top 26 Second connector 28 Optical conductor 30 Mounting hole 32 Liquid crystal display 34 Processor unit 36 Communication unit 38 Optical conductor connector 39 Instruction buffer 40 Network connector 41 Trigger 42 Feedforward control 44 Buffer 46 Text recognition unit 48 Data record or data stream 50 Content recognition unit 52 Parameter storage unit 54 Remote maintenance logic unit 56 Instruction unit 58 Parameter change unit 59 Bus interface 60 Control unit 62 Input unit 64 Remote maintenance system 66 User 68 Control computer 70Remote maintenance control unit 72Server

Claims

1. An adapter (14) for coupling a control device (60) having a display unit (6) to a communication network, wherein the adapter (14) has a carrier (20) and the adapter (14) comprises: a first connector (18) for connecting the adapter (14) to a display port (4) of the control device (60), - a second connector (26) that is electrically connected to the first connector (18) and serves for conducting signals received from the first connector (18) to the second connector (26), - a processor unit (34) and - a data interface (16), wherein the first connector (18) and the second connector (26) are mechanically designed complementary to one another, wherein the processor unit (34) is coupled to the first connector (18) and the data interface (16) and designed for converting control signals, which are received from the first connector (18) and intended for controlling the display unit (6), into a data set or a data stream, as well as for conducting said data set or data stream to the data interface (16), and wherein the data interface (16) is designed for transmitting the data set or data stream to an external communication unit (36) that is signal-connected to the communication network.

2. The adapter (14) according to claim 1, wherein the carrier (20) has a printed circuit board, and wherein the first connector (18) and the second connector (26) are arranged congruently on an underside (22) and an upper side (24) of the carrier (20).

3. The adapter (14) according to claim 1 or 2, wherein the data interface (16) is an optical data interface.

4. The adapter (14) according to one of the preceding claims, furthermore having a feedforward control (42) that is designed for recording the control signals and for decoding said control signals into an illustration intended for the display unit (6).

5. The adapter (14) according to claim 4, wherein the processor (34) has a text recognition unit (46) that is designed for converting the output of the feedforward control (42) into text information.

6. The adapter (14) according to claim 5, wherein the processor (34) has a content recognition unit (50) that is designed for recognizing specific expressions in the text information.

7. The adapter (14) according to one of the preceding claims, furthermore having an instruction unit (56) that is coupled to the processor (34) and can be connected to ports of an input unit (62) of the control device (60), wherein the instruction unit (56) is designed for generating electrical signals for simulating manual entries into the input unit (62).

8. The adapter (14) according to claim 7, wherein the processor (34) has a parameter changing unit (58) that is coupled to the instruction unit (56) and designed for automatically polling parameters, which can be purposefully changed in succession by means of the instruction unit (56), from the control device (60) and / or for changing parameters specified by a user by means of the instruction unit (56) in the control device (60) as a result of purposeful entries.

9. A remote maintenance system (64) having at least one adapter (14) according to one of the preceding claims and a communication unit (36), wherein the at least one adapter (14) can be connected to the communication unit (36).

10. The remote maintenance system (64) according to claim 9, wherein the communication unit (36) is a data network device.

11. The remote maintenance system (64) according to claim 9 or 10, wherein the remote maintenance system has multiple adapters (14), and wherein the communication unit (36) has multiple adapter ports (38) for respectively connecting the adapters (14).

12. The remote maintenance system (64) according to one of claims 9 to 11, wherein the at least one adapter (14) and the communication unit (36) are designed for producing a galvanically isolated connection to one another.

13. A method for coupling a control device (60) having a display unit (6) to a communication network, with said method comprising the steps of: - decoupling the display unit (6) from the display port (4) of the control device (60), - connecting a first connector (18) of an adapter (14) to the display port (4) of the control device (60), - converting control signals, which are received via the first connector (18) and originally intended for controlling the decoupled display unit (6), into a data set or a data stream in the adapter (14), and - transmitting the data set or the data stream to an external communication unit (36) that is signal-connected to the communication network.

14. The method according to claim 13, furthermore comprising the steps of: - connecting the decoupled display unit (6) to a second connector (26) of the adapter (14), which second connector is mechanically designed complementary to the first connector (18), and - displaying data by means of the display unit (6) in accordance with the received control signals.

15. The method according to claim 13 or 14, furthermore comprising the steps of: - connecting an instruction unit (56) of the adapter (14) to ports of an input unit (62) of the control device (60), and - simulating manual entries into the input unit (62) of the control device (60) by means of the instruction unit (56) of the adapter (14).