DE102012109348A1 - Method for operating field device e.g. volumetric flow meter, in automatic control engineering, involves linking permissible parameters with user role by role-parameter-matrix, where parameters are determined based on user role - Google Patents

Abstract

The method involves inputting password assigned to specific user role, and providing access rights to parameters of field devices (F1-F4) based on the specific user role, where the field devices are connected with computer units (WS1) over a data bus (D1). The specific user role is determined based on the inputted password. Permissible parameters of the field device are released, where the permissible parameters are linked with the specific user role by a role-parameter-matrix (RP). The permissible parameters are determined based on the user role.

Description

The invention relates to a method for safe operation of a field device of automation technology.

In process automation technology, field devices are often used to detect and / or influence process variables. Sensors such as fill level measuring devices, flowmeters, pressure and temperature measuring devices, pH redox potential measuring devices, conductivity measuring devices, etc., which record the corresponding process variables level, flow, pressure, temperature, pH or conductivity, are used to record process variables. To influence process variables are actuators, such as valves or pumps, through which the flow of a liquid in a pipe section or the level can be changed in a container. In principle, field devices are all devices that are used close to the process and that provide or process process-relevant information. In addition to the aforementioned sensors and actuators, field devices are generally also understood as meaning those units which are connected directly to a field bus and serve to communicate with the superordinate units, such as e.g. Remote I / Os, Gateways, Linking Devices and Wireless Adapters. A large number of such field devices are manufactured and distributed by the Endress + Hauser Group.

Before commissioning and changing the function during operation of the field device at the field device operator, the field devices must be parameterized or configured using parameters. For parameterization, in particular for reading and / or writing parameters, operating tools or operating tools are used. Such operating tools are usually implemented on a separate from the respective field device communication unit and are connected via a fieldbus or via a service interface of the field device (possibly also communicates with a manufacturer-specific protocol) with the field device in communication.

In order that no cyclic adjustment of all data, in particular of parameters provided in the field device, must take place between an operating tool communicating with the field device and the field device, a distinction is made between static parameters and dynamic parameters of a field device. Dynamic parameters, such as measured values, status information, error messages, etc., change their value in particular as a function of the process variables to be measured or influenced and / or as a function of the device status of the field device. As a rule, dynamic parameters of the field device are cyclically read by a higher-level unit which carries out the process control or written cyclically in the case of a positioning command in the context of a cyclic communication. In contrast, static parameters change only if something changes in the device configuration of the field device. Such a change of the device configuration is usually done by operating the field device via an operating tool or via a local operation. Such an operation is usually performed by a user or by a higher-level system or a higher-level computer unit. A cyclic readout of static parameters is not provided here.

However, this possibility of changing the device configuration by a user or operator or by a higher-level system entails the risk that the device was not parameterized correctly, since certain knowledge of, for example, the measurement principle, the physical process observed by the field device for changing parameter values and / or influenced, are necessary. Often, the operator or user does not have sufficient knowledge of this, so that it comes by incorrect accidentally changing the static parameters to incorrect settings. In addition, a deliberate manipulation of the parameter values is conceivable.

The invention has for its object to propose a field device that is designed such that it can be operated as safely as possible by an operator.

• – Eingabe des Passwortes,
• – Ermittlung, der entsprechend des eingegebenen Passwortes, hinterlegten spezifischen Benutzerrolle,
• – Freigabe der zulässigen Parameter des Feldgerätes, wobei die zulässigen Parameter durch eine Rollen-Parameter-Matrix mit der spezifischen Benutzerrolle verknüpft sind und die zulässigen Parameter anhand der hinterlegten Benutzerrollen ermittelt werden.

According to the invention, the object is achieved by a method for operating a field device of automation technology, wherein the field device can be operated via a communication interface and an operator logs on to the field device via a password which is assigned to a specific user role, access rights to parameters based on the specific user role of the field device are assigned and the field device only activates the permissible parameters for parameterizing the field device and wherein the method for logging on to the field device provides the following method steps:

• - entering the password,
• Determination, according to the entered password, stored specific user role,
• - Release of the permissible parameters of the field device, whereby the permissible parameters are linked by a role parameter matrix with the specific user role and the permissible parameters are determined on the basis of the stored user roles.

According to the invention, the method is solved in that each operator or user must log on to the field device via a password which is assigned to a specific user role, which in turn has corresponding rights with regard to the access to the field device, in particular the access to static parameters. Are defined.

• – Eingabe eines Masterpasswortes,
• – Überprüfung des Masterpasswortes auf Richtigkeit,
• – Vergabe neuer und/oder Anpassung bestehender Benutzerrollen,
• – Speicherung der neu vergebenen und/oder angepassten bestehenden Benutzerrollen in der Rollen-Parameter-Matrix.

An advantageous embodiment of the method according to the invention provides the following sub-steps for assigning and / or adapting and / or changing the user roles by the operator or the field device operator of the field device:

• - input of a master password,
• - checking the master password for correctness,
• - allocation of new and / or adaptation of existing user roles,
• - Storage of the newly assigned and / or adapted existing user roles in the role parameter matrix.

An alternative embodiment of the method according to the invention provides that the field device manufacturer carries out the assignment and / or adaptation and / or modification of the user roles in the role parameter matrix.

An advantageous embodiment of the method according to the invention provides that the visibility and / or the read and / or write permissions for the parameters are determined role-specific via the role parameter matrix.

A further advantageous embodiment of the method according to the invention provides that an LDAP server (Lightweight Directory Access Protocol) is used to manage the specific user roles and / or activation of the allowable parameters to be enabled on the field device according to the specific user roles. This offers the advantage that a central assignment of the user roles with the corresponding access rights to the permissible parameters for all field devices is possible. For this purpose, the LDAP server is used to manage the access code and / or to carry out the access control for the field devices. The invention will be explained in more detail with reference to the following drawings. It shows:

1 : a schematic representation of a network of process automation technology with multiple field devices,

2 a flowchart for the logon process to a field device according to a preferred embodiment of the method according to the invention.

1 shows a schematic representation of a network of process automation technology with multiple field devices F1-F4, which are connected via a data bus D1 to several computer units (workstations) WS1, WS2. These computer units WS1, WS2 can serve as higher-level units (control systems or control units) for process visualization, process monitoring and engineering but also for operating and monitoring the field devices F1-F4. The data bus D1 operates according to a common standard in process automation technology (PROFINet, HSE - High Speed Ethernet, proprietary Ethernet protocol, etc.). Via a gateway G1, which is also referred to as a linking device, the data bus D1 is connected to a fieldbus segment. The fieldbus segment comprises a plurality of field devices F1-F4 which are connected to one another via a field bus FB. The field devices F1-F4 can be both sensors and actuators. The fieldbus FB operates according to one of the known fieldbus standards, Foundation Fieldbus or HART. A portable computer unit or operating unit BE can be temporarily connected to the fieldbus FB, which serves for operation, in particular for parameterization, of one of the field devices F1-F4. For this purpose, it is provided that the operating unit BE communicates via the fieldbus FB with one or more specifically selected field devices F1-F4.

Alternatively, the operating unit BE can also have a wireless communication interface, via which communication with one or more specifically selected field devices F1-F4 is possible. By means of this communication, for example, a parameterization of the field devices F1-F4 is possible. To do this, an operator must log on to the corresponding field devices F1-F4 by entering a password.

Further shows 1 an LDAP server LDAP, which is used to manage the specific user roles or the management of the access identifier and / or the activation of the permissible parameters to be enabled according to the specific user roles on the field device F1-F4. For this purpose, in the field device F1-F4, the IP address and the access identifier including the password for logging on the LDAP server LDAP stored in order to enable the field device F1-F4 to communicate with the LDAP server LDAP. The role parameter matrix RP is thus also stored on the LDAP server LDAP and links the permissible parameters to be released with the corresponding specific user role.

To access the field device F1-F4, the operator logs in by entering the password on the field device F1-F4. After entering the password, the field device F1-F4 inquires at LDAP server LDAP, if the password is assigned to a specific user role and if necessary, informs field device F1-F4 of the specific assigned user role. Field device F1-F4 then authorizes the operator and allows access to the allowable parameters to be unlocked associated with the specific user role.

It goes without saying that in the event that the entered password is not associated with a specific user role, the field device F1-F4 denies access by the operator.

Furthermore, after a successful login or after the successful access to the field device F1-F4, the role parameter matrix RP is locally stored on the corresponding field device F1-F4, thus the logon to the field device continues when the connection to the LDAP server LDAP is interrupted To allow F1-F4.

The use of an LDAP server LDAP offers in addition to the advantage that the management of the access identifier and / or the execution of access control centrally feasible for a variety of field devices and the advantage that resets forgotten passwords using the LDAP server and / or re-activated without having to directly intervene on the field device F1-F4. Thus, the administration of the field devices F1-F4 considerably simplifies the use of an LDAP server, since in the case that no LDAP server is used, the forgotten password would have to be reset and / or re-activated on each field device.

For example, it is conceivable that the field device manufacturer specifies a standard scope of user roles and the operator independently determines whether or not the LDAP server LDAP with the default user roles is used. Of course, the operator has the opportunity to make adjustments to existing and / or assigning new user roles.

2 shows a flow chart for the already indicated sign-on process on a field device F1-F4 according to the inventive method. For this, as already described, the operator must log on to the field device F1-F4 via a password for each login. On the basis of this entered password, a routine then takes place which determines the appropriate user role for the entered password. After the suitable user role has been determined, the static parameters permissible for the operator according to the user role are enabled for the parameterization. For this purpose, the permissible parameters are linked by a role parameter matrix RP with the corresponding user roles. In the event that no suitable user role is found, access to the field device is denied.

The role parameter matrix RP specifically defines its visibility (validity) or its read and / or write rights (handling) within a user role for each individual parameter of the field device. Furthermore, it is conceivable that individual parameters are grouped together and thus all parameters of the group get the same visibility or the same read and / or write rights. For example, the user role "A" should be able to configure or parameterize warning and / or alarm limits of a particular parameter. Whereas the user role "B" should only be able to see these parameters or limits and the user role "C" should not see the parameters or the limits at all.

The determination of the visibility (validity) or the read and / or write rights (handling) according to the corresponding user role can be carried out in two ways. On the one hand, the assignment and / or adaptation and / or modification of the user roles in the role parameter matrix RP can be carried out by the field device manufacturer. Here, the user roles for the operator of the field device are static, i. There is no possibility for the operator to change the access rights to a parameter or to change the link between a parameter and the user roles stored in the role parameter matrix RP.

• – Eingabe eines Masterpasswortes durch den Bediener bzw. Feldgerätebetreiber beim ersten Verbindungsaufbau, wobei das Masterpasswort vom Feldgerätehersteller werkseitig als initiales Masterpasswort hinterlegt wird. Der Bediener bzw. Feldgerätebetreiber kann somit, nach Eingabe und Überprüfung des Masterpasswortes auf dessen Richtigkeit, auf die Rollen-Parameter-Matrix RP zugreifen. Ferner ist er in der Lage, das werkseitig hinterlegte initiale Masterpasswort durch ein von ihm ausgewähltes Passwort zu ersetzen, umso einen Zugriff auf das Feldgerät F1–F4 durch nicht autorisierte Bediener zu unterbinden.
• – Vergabe neuer und/oder Anpassung bestehender Benutzerrollen. Hierzu kann der Bediener die Zuordnung bestehender Zugriffsrechte bzw. bestehender Verknüpfungen zwischen Benutzerrollen und den entsprechenden zulässigen Parametern selbstständig anpassen oder ggfl. auch neue Zuordnungen bzw. Verknüpfungen erstellen.
• – Speicherung der neu vergebenen und/oder angepassten bestehenden Benutzerrollen in der Rollen-Parameter-Matrix RP.

On the other hand, the assignment and / or adaptation and / or modification of the user roles in the role parameter matrix RP can be performed by the operator or the field device operator. Here, the user roles for the operator are dynamic and it is possible for the operator to change the access rights to a parameter or to change the link between a parameter and the user roles stored in the role parameter matrix RP. For this purpose, the method provides the following sub-steps:

• - Input of a master password by the operator or field device operator at the first connection, the master password is factory-stored by the field device manufacturer as an initial master password. The operator or field device operator can thus access the role parameter matrix RP after entering and checking the master password for its correctness. Furthermore, he is able to replace the factory-stored initial master password by a password selected by him, so as to prevent access to the field device F1-F4 by unauthorized operators.
• - Allocation of new and / or adaptation of existing user roles. For this purpose, the operator can independently adjust the allocation of existing access rights or existing links between user roles and the corresponding permissible parameters or ggfl. also create new assignments or links.
• - Storage of newly assigned and / or adapted existing user roles in the role parameter matrix RP.

LIST OF REFERENCE NUMBERS

F1-F4

field device

RP

Roller parameter matrix

LDAP

LDAP server

WS1, WS2

Computer units or workstation

D1

bus

G1

gateway

BE

operating unit

FB

fieldbus

Claims (5)

Method for operating a field device (F1-F4) of the automation technology, which can be operated via a communication interface, wherein an operator logs on to the field device (F1-F4) via a password which is assigned to a specific user role, access rights based on the specific user role are assigned to parameters of the field device (F1-F4) and the field device (F1-F4) only enables the permissible parameters for parameterizing the field device and wherein the method for logging on to the field device provides the following method steps: - entering the password, Determination, according to the entered password, stored specific user role, - Release of the permitted parameters of the field device (F1-F4), whereby the permissible parameters are linked by a role parameter matrix (RP) with the specific user role and the permissible parameters are determined based on the stored user roles. Method according to Claim 1, the method providing the following sub-steps for allocating and / or adapting and / or changing the user roles by the operator of the field device (F1-F4): - input of a master password, - checking the master password for correctness, - allocation of new and / or adaptation of existing user roles, - Storage of the newly assigned and / or adapted existing user roles in the role parameter matrix (RP). The method of claim 1, wherein the method provides that the field device manufacturer performs the assignment and / or adaptation and / or modification of the user roles in the role parameter matrix (RP). Method according to one or more of the preceding claims, wherein the visibility and / or the read and / or write rights for the parameters are determined role-specific via the role parameter matrix (RP). Method according to one or more of the preceding claims, wherein an LDAP server (LDAP) is used to manage the specific user roles and / or activation of the allowable parameters to be enabled according to the specific user roles on the field device (F1-F4).

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