DE102022109134A1 - Access method to a field device in process automation technology - Google Patents

Abstract

Specified is a secure access method to a field device of process automation technology, wherein the field device is connected to the company network, the company network comprising a higher-level unit ÜE and an input device EG, which is arranged in an access-secured area ZB, the access-secured area ZB being locally isolated and can only be accessed by a group of people with authorization level 1.

Description

The invention relates to an access method to a field device in process automation technology.

From the WO2007/025879 is an arrangement for operating a field device in process automation technology, in which the field device is accessed wirelessly using an operating unit. Changing the device is problematic. This requires considerable effort.

From the DE102011083984A1 a method for ensuring authorized access to a field device in automation technology is known. However, unauthorized data interference or data access cannot be ruled out here.

From the DE 102014105076 A1 Another method for secure access of a mobile operating unit to a field device is known. In particular, the field device should be protected from unauthorized access via a mobile operating unit, especially with regard to data theft.

This method enables verification codes to be transmitted between an administrative unit and a mobile operating device in order to enable access to field devices. The disadvantage of this method is that the management unit does not plan to change the factory-assigned code in the field devices.

From the DE 10 2013 202 564 A1 is another access method for parameterizing a bus participant, e.g. B. a field device, known in a fieldbus, which works with a QR code.

This procedure makes the transfer of parameterization or system information easier and errors caused by manual input are largely avoided. It also ensures that the operator is using the correct device and there can be no mix-up.

The disadvantage of this access method is that no precautions are taken to authenticate the operator. This means that unauthorized access to data on the field device cannot be prevented.

The object of the invention is to provide a secure access method to a field device in process automation technology that does not have the above-mentioned disadvantages and is practical and easy to implement.

This task is solved by the method specified in claim 1.

Advantageous further developments of the invention are specified in the subclaims.

The essential idea of the invention is that the user must be in an access-secured area when requesting the authorization key from the higher-level unit. Only then is the authorization key generated in the higher-level unit and transmitted to an output device, which is also located in the access-secured area.

Since the user is in the access-secured area, he receives a first authorization level that is available to anyone who has access to the access-controlled area. The authorization key shown on the display of the output device AG as an optical pattern (QR code) is z. B. recorded with a smartphone and stored in it. The user can then log into the process environment area, i.e. H. the area in which the field device to be operated is located by transmitting the authorization key from his smartphone to a network unit that is also located in the process environment area. If the user is successfully authenticated, access to the field device is released in accordance with the authorization level assigned to the authorization key.

The invention is explained in more detail below using an exemplary embodiment shown in the drawing.

• 1 Firmennetzwerk mit zwei separaten Bereichen Prozessumgebung/Zugangsgesicherter Bereich
• 2 Mesh-Netzwerk
• 3 klassische Automatisierungspyramide Cyber-physikalisches-Automatisierungs-System
• 4 Mesh-Netzwerk der Automatisierungstechnik

Show it:

• 1 Company network with two separate areas: process environment/access-secured area
• 2 Mesh network
• 3 classic automation pyramid cyber-physical automation system
• 4 Mesh network of automation technology

1 shows a company network with a higher-level unit ÜE (control or PC), which is connected to various units in a process environment PU and to various units in an access-secured area ZB, which is locally isolated.

The network units in the process environment PU are a network component NK z. B. a gateway and several field devices FG1, FG2, which are connected the gateway are connected. are connected.

The units in the access-secured area ZG are an input device EG on which the user B can log in and an output device AG on which a display D is provided.

User B can wirelessly access certain units in the process environment PU.

2 shows a concrete example of a company network, where in the process environment a base station acts as a gateway GW and field devices FG1, FG2 communicate as a mesh adapter via Bluetooth. The higher-level controller is a PC that communicates with an IO-Link master to which an IO-Link display is connected.

3 The left shows a classic company network as an automation pyramid, with several field devices at the field level. Previously, access to a field device could only be done on site using a key input or via a wired control unit

3 on the right shows a corresponding cyber physical system, with strong networking, especially wireless networking, which represents the future development trend. In such systems, secure data access is essential.

4 shows an automation technology mesh network with several field devices that are wirelessly connected to a gateway. The gateway is connected to an Ethernet-based communication network.

The method according to the invention is explained in more detail below.

The user is on the company premises or in a specific area of the company that has secured access. Simply because the user can enter this area, he already has a certain authorization to operate individual units in the process environment.

In a first procedural step, the user logs on to the input device and requests an authorization key for access, for example. B. on the field device FG1.

It is not absolutely necessary that the user authenticates himself on the input device EG. Reading out a measured value from the field device FG is certainly possible for a larger group of users. If changes to the field device in terms of configuration or parameterization are to be possible with the authorization key, personal identification of the user on the input unit EG is required (key card/company ID, etc.)

The different authorization keys with the assigned different users or user groups are stored in the higher-level unit.

In the next method step, the authorization key that is assigned to the user is generated in the higher-level unit ÜE and then transmitted to the output device AG, which is arranged in the access-secured area.

Depending on the user's authorization level, the authorization key can be different. However, since the user was able to enter the access-secured area, he has at least authorization level 1.

The sent authorization key is displayed optically as a sample on the output device, e.g. B. shown as a QR code.

The user takes the pattern, i.e. H. because the optically displayed authorization key key1 with his operating device. The authorization key key1 is saved in the operating device.

The user then goes to the process environment, where, depending on the authorization level, he only wants to read sensor data or change parameter values.

In the next procedural step, the user must log in to the network and authenticate as an authorized user. To do this, it transmits the authorization key to one of the network components, either the gateway GW or to one of the field devices FG1, FG2.

If the network key transmitted by the user to the network component matches the authorization key available directly on a network component in the company network or the authorization key key1 that can be queried via the company network, access to the field device is released according to the authorization level.

Various application examples are described in more detail below.

1. 1. Der Benutzer (Leseberechtigter Werker) erhält mit seiner Key-Card (Firmenausweis) Zutritt in einen zugangsgesicherten Raum.
2. 2. Er authentifiziert sich mit seiner Key-Card an dem RFID Eingabegerät
3. 3. Die übergeordnete Einheit prüft die Berechtigung des Werkers und generiert davon abhängig ein Berechtigungsschlüssel (hier Leseberechtigung) key1.
4. 4. Die übergeordnete Einheit überträgt den neu generierten Berechtigungsschlüssel an das Ausgabegerät (IO-Link Display), sowie über die Basisstation an alle betroffenen Mesh-Adapter
5. 5. Der Werker scannt mit seinem Mobiltelefon den QR-Code mit dem Berechtigungsschlüssel auf dem Display ab.
6. 6. Der Werker kann nun mit seinem Mobiltelefon über Bluetooth eine Verbindung zu den Mesh Adaptern aufbauen. Die App authentifiziert sich mit dem erhaltenen Schlüssel auf dem jeweiligen Mesh Adapter.
7. 7. Der Werker erhält nun Zugriff auf die Parameter/Daten des Adapters und kann diese auslesen, jedoch nicht verändern

Application example 1:

1. 1. The user (read-authorized worker) gains access to a secure room with his key card (company ID).
2. 2. He authenticates himself with his key card on the RFID input device
3. 3. The higher-level unit checks the worker's authorization and, depending on this, generates an authorization key (here read authorization) key1.
4. 4. The higher-level unit transmits the newly generated authorization key to the output device (IO-Link display) and via the base station to all affected mesh adapters
5. 5. The worker scans the QR code with the authorization key on the display using his mobile phone.
6. 6. The worker can now establish a connection to the mesh adapters with his mobile phone via Bluetooth. The app authenticates itself with the received key on the respective mesh adapter.
7. 7. The worker now has access to the adapter's parameters/data and can read them, but cannot change them

1. 1. Leseberechtigter Benutzer (Werker) bekommt mit seiner Key-Card Zutritt in einen abgeschlossenen Raum.
2. 2. Der Werker authentifiziert sich mit seiner Key-Card an dem RFID Eingabegerät
3. 3. Die übergeordnete Steuerung prüft die Berechtigung des Werkers und generiert davon abhängig ein Zugriffsschlüssel (hier im Beispiel Leseberechtigung)
4. 4. Die übergeordnete Steuerung überträgt den neu generierten Zugriffsschlüssel an das Ausgabegerät (IO-Link Display) und speichert diesen lokal ab. Es werden keine Zugriffsschlüssel an die Adapter übertragen.
5. 5. Der Werker scannt mit seinem Mobiltelefon den QR-Code mit dem Berechtigungsschlüssel auf dem Display ab.
6. 6. Der Werker kann nun mit seinem Mobiltelefon über Bluetooth eine Verbindung zu den Mesh Adaptern aufbauen.
7. 7. Die App authentifiziert sich mit dem erhaltenen Schlüssel auf dem jeweiligen Mesh Adapter. Der Mesh Adapter sendet die erhaltenen Authentifizierungsdaten über das Mesh Netzwerk zu der übergeordneten Steuereinheit. Diese prüft die Authentifizierungsdaten und sendet eine Antwort mit den Berechtigungen zurück an den Adapter
8. 8. Der Werker erhält nun Zugriff auf die Parameter/Daten des Adapters und kann diese auslesen, jedoch nicht verändern

Application example 2:

1. 1. Read-authorized user (worker) gains access to a locked room with his key card.
2. 2. The worker authenticates himself with his key card on the RFID input device
3. 3. The higher-level control checks the worker's authorization and, depending on this, generates an access key (here in the example read authorization)
4. 4. The higher-level controller transfers the newly generated access key to the output device (IO-Link display) and saves it locally. No access keys are transmitted to the adapters.
5. 5. The worker scans the QR code with the authorization key on the display using his mobile phone.
6. 6. The worker can now establish a connection to the mesh adapters with his mobile phone via Bluetooth.
7. 7. The app authenticates itself with the received key on the respective mesh adapter. The Mesh Adapter sends the received authentication data over the Mesh network to the higher-level control unit. This checks the authentication data and sends a response with the permissions back to the adapter
8. 8. The worker now has access to the parameters/data of the adapter and can read them, but cannot change them

1. 1. Schreibberechtigter Benutzer (Techniker) bekommt mit seiner Key-Card Zutritt in einen abgeschlossenen Raum.
2. 2. Der Techniker authentifiziert sich mit seiner Key-Card an dem RFID Eingabegerät
3. 3. Die übergeordnete Steuerung prüft die Berechtigung des Werkers und generiert davon abhängig 2 Zugriffsschlüssel mit vollwertiger Schreibberechtigung. Einen für die Mesh Basisstation und einen für alle Mesh Adapter.
4. 4. Die übergeordnete Steuerung überträgt die neu generierten Zugriffsschlüssel an das Ausgabegerät (IO-Link Display) und speichert diese lokal ab (die Zugriffsschlüssel könnten auch direkt an die Geräte übertragen werden, wie in Anwendungsbeispiel 1 beschrieben).
5. 5. Der Techniker scannt mit seinem Mobiltelefon den QR-Code mit den Berechtigungsschlüsseln auf dem Display ab.
6. 6. Der Werker kann nun mit seinem Mobiltelefon über Bluetooth eine Verbindung zu den Mesh Adaptern oder der Basisstation aufbauen.
7. 7. Die App authentifiziert sich mit dem erhaltenen Schlüssel auf dem jeweiligen Gerät. Der Mesh Adapter/Basisstaion sendet die erhaltenen Authentifizierungsdaten über das Mesh Netzwerk zu der übergeordneten Steuereinheit. Diese prüft die Authentifizierungsdaten und sendet eine Antwort mit den Berechtigungen zurück an das Gerät.
8. 8. Der Techniker erhält nun vollwertigen Schreib- und Lesezugriff auf die Mesh Adapter oder die Basisstation und kann Änderungen vornehmen.

Application example 3:

1. 1. Write-authorized user (technician) gains access to a locked room with his key card.
2. 2. The technician authenticates himself with his key card on the RFID input device
3. 3. The higher-level control checks the worker's authorization and, depending on this, generates 2 access keys with full write authorization. One for the mesh base station and one for all mesh adapters.
4. 4. The higher-level controller transfers the newly generated access keys to the output device (IO-Link display) and saves them locally (the access keys could also be transferred directly to the devices, as described in application example 1).
5. 5. The technician uses his mobile phone to scan the QR code with the authorization keys on the display.
6. 6. The worker can now use his mobile phone to establish a connection to the mesh adapters or the base station via Bluetooth.
7. 7. The app authenticates itself with the received key on the respective device. The mesh adapter/base station sends the received authentication data via the mesh network to the higher-level control unit. This checks the authentication data and sends a response with the authorizations back to the device.
8. 8. The technician now has full read and write access to the mesh adapter or base station and can make changes.

1. i. Anforderung eines Berechtigungsschlüssels key von der übergeordneten Einheit ÜE durch einen Benutzer an dem Eingabegerät EG in dem zugangsgesicherten Bereich ZB
2. ii. Generierung eines Berechtigungsschlüssel key in der übergeordneten Einheit
3. iii. Übertragen des generierten Berechtigungsschlüssels key von der übergeordneten Einheit ÜE an ein Ausgabegerät AG das im zugangsgesicherten Bereich angeordnet ist, wobei der Berechtigungsschlüssel key mindestens einem Berechtigungslevel 1 entspricht
4. iv. Darstellung des Berechtigungsschlüssels key auf einem Display des Ausgabegeräts AG als optisches Muster (QR-Code)
5. v. Erfassen des optischen Musters mit einem Handbediengerät HG (Smartphone/Tablet/ handheld device)
6. vi. Speichern des Berechtigungsschlüssels key, der dem optischen Muster zugeordneten ist, im Handbediengerät HG
7. vii. Authentifizierung des Benutzers im Prozessumgebungs-Bereich durch Übertragung des Berechtigungsschlüssels key von seinem Handbediengerät HG an eine Netzwerkeinheit
8. viii. Bei erfolgreicher Authentifizierung des Benutzers B Freigabe der Zugriffe auf das Feldgerät FG der Automatisierungstechnik entsprechend der dem Berechtigungsschlüssel key zugeordnete Berechtigungslevels

The method steps of the secure access method according to the invention to a field device of process automation technology are given below, the field device being connected to the company network, the company network comprising a higher-level unit ÜE and an input device EG, which is arranged in an access-secured area ZB, the access-secured area For example, it is locally isolated and can only be accessed by a group of people with authorization level 1:

1. i. Request an authorization key from the higher-level unit ÜE a user on the input device EG in the access-secured area ZB
2. ii. Generation of an authorization key key in the parent unit
3. iii. Transmitting the generated authorization key key from the higher-level unit ÜE to an output device AG which is arranged in the access-secured area, the authorization key key corresponding to at least one authorization level 1
4. iv. Representation of the authorization key on a display of the output device AG as an optical pattern (QR code)
5. v. Capturing the optical pattern with a handheld device HG (smartphone/tablet/handheld device)
6. vi. Saving the authorization key, which is assigned to the optical pattern, in the hand-held control device HG
7. vii. Authentication of the user in the process environment area by transmitting the authorization key key from his handheld control device HG to a network unit
8. viii. If user B is successfully authenticated, access to the field device FG of the automation technology is released in accordance with the authorization level assigned to the authorization key key

• Die zur Authentifizierung des Benutzers erforderlichen Informationen (Identifikationen) werden von der übergeordneten Einheit ÜE automatisch wieder in das Gateway oder das Feldgerät übertragen. Ein Gerätewechsel ist deshalb unproblematisch.

The following advantages can be achieved with the method according to the invention:

• The information (identifications) required to authenticate the user are automatically transferred back to the gateway or the field device by the higher-level unit ÜE. Changing the device is therefore unproblematic.

According to the present invention, the method provides for changing the verification code both in the mobile operating device and in the field device FG or in the gateway. This increases both flexibility and security.

A controller or a PC serves as the higher-level unit ÜE, which represents an administrative device and is designed as a server.

It is possible to transfer different authorization keys (depending on the user's qualifications) to the mobile handheld control device HG in order to activate different access levels (authorization levels) in the field device FG (terminal device).

The authorization key (access code) is automatically transmitted via the higher-level unit (server) to both the field device FG and the hand-held control device HG.

The method according to the invention can be used in different forms for access authorization to the field devices FG. This makes it very flexible. However, it always requires some form of authentication. This makes unauthorized access much more difficult.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was 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

• WO 2007025879 [0002]
• DE 102011083984 A1 [0003]
• DE 102014105076 A1 [0004]
• DE 102013202564 A1 [0006]

Claims (1)

Secure access method to a field device of process automation technology that is connected to a company network, the company network comprising a higher-level unit and an input device that is arranged in an access-secured area, the access-secured area being locally isolated and only accessible by a group of people with authorization at the authorization level 1 can be entered, characterized by the following procedural steps: i. Request of an authorization key from the higher-level unit ÜE by a user on the input device EG in the access-secured area ZB ii. Generation of an authorization key key in the parent unit iii. Transmitting the generated authorization key key from the higher-level unit ÜE to an output device AG which is arranged in the access-secured area, the authorization key key corresponding to at least one authorization level 1 iv. Representation of the authorization key on a display of the output device AG as an optical pattern (QR code) v. Capturing the optical pattern with a handheld device HG (smartphone/tablet/handheld device) vi. Saving the authorization key, which is assigned to the optical pattern, in the hand-held control device HG vii. Authentication of the user in the process environment area by transmitting the authorization key key from his handheld control device HG to a network unit viii. If user B is successfully authenticated, access to the field device FG of the automation technology is released in accordance with the authorization level assigned to the authorization key key

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