Wireless configuration of field devices

Abstract

Field device for process automation, comprising: a first radio interface (108) for wireless communication with an operating device (103); a control element (109) for initiating the setup of a wireless communication network in which the field device is used as the network host; a control circuit (110) for: Setting up the wireless communication network as a network host; Decrypting encrypted configuration data received from the operator device via the wireless communication network; Dismantling of the wireless communication network; Establishing a wireless communication connection to an encrypted communication network as a network client using the configuration data.

Description

Field of the invention

[0001] The invention relates to the configuration of field devices. In particular, the invention relates to a field device with a radio interface via which the field device can be parameterized, a method for parameterizing field devices, a program element, and a computer-readable medium. background

[0002] Field devices for process automation include, for example, level measuring devices, pressure measuring devices, flow measuring devices, or point level sensors. To equip these field devices for the respective measuring task, the devices are parameterized (configured) by the user. This parameterization can be performed directly on the field device using user input, for example. Alternatively, a control element can be connected to the field device, via which the parameterization is performed. In principle, it is also possible to perform this parameterization via a wireless communication connection. This is preferably a secure communication connection to prevent misuse.

[0003] DE 10 2017 100 348 A1 describes a field device and a method for providing broadcast information.

[0004] DE 10 2012 214 018 B3 describes the authorization of a user by a portable communication device.

[0005] WO 2017 / 013488 A1 describes a selective pairing of wireless devices using shared keys. Summary of the invention

[0006] It is an object of the invention to enable a user to parameterize a field device wirelessly, i.e. without electrical contact, in a simple way.

[0007] This object is achieved by the features of the independent claims. Further developments of the invention emerge from the subclaims and the following description of embodiments.

[0008] A first aspect of the invention relates to a field device for process automation, which has a first radio interface for wireless communication with an operating device. The field device has an operating element, for example in the form of a key, a button, a motion sensor, or a touch-sensitive detector. After operation by the user, the operating element initiates the establishment of a wireless communication network by the field device, in which the field device is used as a network host. Furthermore, a control circuit is provided, which subsequently establishes the wireless communication network as a network host and, after the network has been established, decrypts encrypted configuration data received from the operating device and then dismantles the wireless communication network.The decrypted configuration data is then used to establish a wireless communication connection to an existing, encrypted communication network as a network client.

[0009] In particular, the field device can be designed to dismantle the previously established wireless communication network only if it has received encrypted configuration data from the operator device for establishing the connection to the encrypted communication network.

[0010] For example, it may be provided that the wireless communication network to be set up is a publicly accessible communication network, for example according to the Bluetooth standard, the WLAN standard or a communication network that transmits the information acoustically.

[0011] The control element can be designed to detect a user movement to initiate the establishment of the wireless communication network. For example, gesture recognition can be provided.

[0012] For example, the first radio interface is a WLAN radio interface. Additional radio interfaces can also be provided, for example, a Bluetooth radio interface and / or an acoustic radio interface designed for wireless communication with acoustic signals. The field device can be designed to establish the communication network sequentially, first via the first (or second) radio interface, then via the second (or first) radio interface, and then via the third radio interface, until the encrypted configuration data has been received via the wireless communication network.

[0013] The network is then dismantled again and the connection is made to the encrypted communication network that is already provided externally.

[0014] A further aspect of the invention relates to a method for parameterizing field devices, which performs the steps described above. Furthermore, a further aspect of the invention relates to a program element which, when executed in a control circuit of a field device, instructs the field device to perform the steps described above.

[0015] A further aspect of the invention relates to a computer-readable medium on which the program element described above is stored. Short description of the characters Fig. 1 shows a field device and an operating device according to an embodiment of the invention. Fig. 2 shows a field device and an operating device according to another embodiment of the invention. Fig. 3 shows a flowchart of a method according to an embodiment of the invention. Fig. 4 shows a flowchart of a method according to another embodiment of the invention. Detailed description of embodiments

[0016] The illustrations in the figures are schematic and not to scale. Where the same reference symbols are used in the following description of the figures, they refer to identical or similar elements.

[0017] Fig. Figure 1 shows a field device and an operator panel according to one embodiment of the invention. The field device is to be parameterized using a signal (Bluetooth, acoustic, or Wi-Fi). To start the parameterization process—for example, with a sensor that is not yet registered in the wireless network—the sensor is to switch itself to receive mode after pressing a button. Receive mode can be established by activating a microphone for parameterization, or the sensor can temporarily provide a host connection.

[0018] The control unit can be configured to check the quality of each communication channel of each communication interface and establish a new communication network with the interface over which the communication connection has the highest quality, while dismantling the previous communication network. An energy storage device can also be provided that maintains stable communication for the duration of the communication with multiple communication interfaces.

[0019] The aim of the invention is to enable a user to configure a field device wirelessly, i.e., without electrical contact. Communication is initiated by the user on the field device via WLAN, Bluetooth, and / or acoustic transmission, for example, by pressing a button. The field device then creates a wireless network into which participants can log in and then configure the field device themselves.

[0020] In addition, the physically independent communication channels (WLAN, Bluetooth, acoustic transmission) can be combined in a suitable manner to ensure a stable connection. Furthermore, the invention allows the parameterization of a field device using various user-side operating devices and software (various mobile phones from different manufacturers, computer hardware, tablets, handhelds, operating modules).

[0021] A core aspect of the invention concerns the adaptability of the field device during wireless parameterization, which is initiated by pressing a button. The field device then establishes a network using the available communication channels (WLAN access point, Bluetooth advertising), into which the operating device used for parameterization can connect.

[0022] To achieve the greatest possible hardware-independent flexibility between the operator panel and the field device, thus increasing user convenience, the physical communication layer of the field device is appropriately varied, changed, or deactivated if necessary. The establishment of a dedicated wireless network, the management of corresponding clients (operator panels), and the secure transmission of data between the field device and operator panel are advantages of the invention.

[0023] In addition, the invention optimizes the energy consumption of the field device by selecting the connection type that has the lowest energy consumption for the communication between the field device and the control device.

[0024] The operating device communicates with the field device, which is a sensor, via Bluetooth, for example. If this fails—for example, because Bluetooth is deactivated—the sensor uses different fallback methods on Android and iOS. If the user uses an Android smartphone, the sensor briefly sets up a Wi-Fi access point, which the phone connects to and transmits the required data. The sensor and smartphone then reconnect to the "real" Wi-Fi network. The iOS fallback behaves differently: The iPhone beeps the data at a high frequency (e.g., acoustic signals in the range of 17 to 18 kHz) into the sensor's microphone.

[0025] An important aspect of the invention is that the field device or sensor itself creates a network into which participants can dial in and then parameterize the field device.

[0026] In a first application case according to Fig. 1, a user 107 wishes to parameterize a field device—here in the form of a radar sensor 102—using their smartphone 103. Triggered by pressing button 109 on the field device, the field device with the control unit 110 first establishes a network via its communication interface 108, into which the smartphone can connect.

[0027] In particular, the network can only be activated after a button has been pressed. It can also be a Wi-Fi access point. The smartphone and sensor communicate via an unprotected channel 105, allowing the smartphone to connect to the sensor without a key. The smartphone app and the field device are coordinated in such a way that data can be transmitted encrypted between the smartphone and the sensor. This eliminates "man-in-the-middle" attacks.

[0028] Another use case that Fig. 2, provides an already secured wireless network 101 into which a sensor is to be integrated in order to obtain a secure connection 106 to the network in the future. The smartphone can already connect to the secure network via connection 104.

[0029] To configure the sensor, the sensor 102 initially acts as an access point, which the smartphone can connect to. The access point can be activated, for example, by pressing a button. The smartphone app and the sensor then exchange encrypted data via the unsecured connection 105. For example, the network key for the secure network 101 can be communicated to the sensor 102. Known encryption methods are conceivable for encrypting the data via the unsecured channel. For example, the network key (as an example for the data via the unsecured channel 105) of the secure network 101 can be encrypted with a public key, transmitted to the sensor, and decoded there with the private key.

[0030] If the sensor succeeds in dialing into the secure network 101, the access point can be deactivated, the smartphone then dials back into the secure network and communication then takes place via the secure network 101. The time sequence is shown here in Fig. 3 illustrated for better representation.

[0031] In the use case described above, the app active on the smartphone changes the smartphone's WLAN access point. Initially, the smartphone is connected to the secure network 101 via connection 104. If the app detects the sensor to be configured, connection 104 is interrupted and connection 105 is established. After the key has been successfully handed over to the secure network 101, connection 105 is interrupted and communication resumes via connection 104. Depending on the security settings of the smartphone's operating system, an app cannot change the access point. A user would therefore have to manually log into the corresponding network, which greatly reduces user-friendliness. It is therefore quite sensible to use fallback strategies. For example, the sensor can alternatively send Bluetooth advertising information using suitable Bluetooth hardware. The connection for the key handover orParameterization of 105 is then performed via Bluetooth. After successful parameterization, communication can take place via networks 101, 106, and 104. Instead of Bluetooth parameterization, NFC or acoustic transmission are also possible.

[0032] The WLAN access point is not changed here and operation can be carried out in a simple manner. Fig. 4 a chronological sequence in another sketch.

Claims

[1] Field device for process automation, comprising: a first radio interface (108) for wireless communication with an operating device (103); an operating element (109) for initiating the establishment of a wireless communication network in which the field device is used as a network host; a control circuit (110) for: Establishment of the wireless communication network as a network host; Decrypting encrypted configuration data received from the operator device via the wireless communication network; Dismantling of the wireless communications network; Establish a wireless communication connection to an encrypted communication network as a network client using the configuration data. [2] The field device of claim 1, wherein the wireless communication network is a publicly accessible communication network. [3] Field device according to one of the preceding claims, wherein the operating element (109) is designed to detect a movement of a user in order to initiate the establishment of the wireless communication network. [4] Field device according to claim 3, wherein the operating element (109) is a button, a switch, a touch panel or a gesture recognition device. [5] Field device according to one of the preceding claims, wherein the wireless communication network established by the field device is based on WLAN technology or Bluetooth technology. [6] Field device according to one of the preceding claims, wherein the wireless communication network established by the field device is based on acoustic communication. [7] Field device according to one of the preceding claims, wherein the first radio interface (108) is a WLAN radio interface; wherein the field device has a second radio interface which is a Bluetooth radio interface; and / or wherein the field device has a third radio interface, which is an acoustic radio interface designed for wireless communication by means of acoustic signals. [8] Field device according to claim 7, wherein the control circuit (110) is designed to establish the communication network sequentially via the first, second and then the third radio interface until the encrypted configuration data has been received via the wireless communication network. [9] Method for parameterizing field devices, comprising the steps: Initiating the establishment of a wireless communication network using the field device as a network host through the movement of a user; Establishing the wireless communication network using the field device as a network host; Decrypting encrypted configuration data received from an operating device (103) via the wireless communication network; Dismantling the wireless communication network by the field device; Establishing a wireless communication connection to an encrypted communication network by the field device as a network client using the configuration data. [10] Program element which, when executed on a control circuit of a field device, instructs the field device to perform the following steps: Initiating the establishment of a wireless communication network using the field device as a network host through the movement of a user; Establishing the wireless communication network using the field device as a network host; Decrypting encrypted configuration data received from an operating device (103) via the wireless communication network; Dismantling the wireless communication network by the field device; Establishing a wireless communication connection to an encrypted communication network by the field device as a network client using the configuration data. [11] A computer-readable medium on which a program element according to claim 10 is stored.

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