Patent Publication Number: US-2022236719-A1

Title: Event Related Load Restrictions of a Server of a Control System of a Technical Plant

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to method for operating a technical plant with a control system and to a control system for the technical plant, in particular a process or production plant, which includes an operator station server and an engineering station server, where the engineering station server comprises a computer-implemented design tool via which an automation configuration for an automation of the technical plant is able to be created, and where the engineering station server is configured to transmit the automation configuration to the operator station server for operation and monitoring of the technical plant. 
     2. Description of the Related Art 
     A control system of a technical plant comprises many components that must be planned into a project, loaded and updated during the life cycle of the plant. When changes are made to project planning, the components of a control system (e.g., automation units, and/or operator station server) are loaded from the engineering station server into the operator station server for example. EP 3 623 891 A1 discloses an exemplary control system. 
     A control system in the present context is to be understood as a computer-assisted technical system, which comprises functionalities for displaying, operating and controlling a technical system such as a production plant. The control system, as well as the operator station server and the operator station client, for example, can also comprise what are known as process-related or production-related components that serve to activate actuators or sensors. 
     The technical plant can involve a plant from the process industry, such as a chemical, pharmaceutical or petrochemical plant or a plant from the food and drink and tobacco industry. Also encompassed by this is any plant from the production industry, works in which, for example, cars or all kinds of goods are produced. Technical plants, which are suitable for implementing the inventive method, can also come from the area of energy generation. Wind turbines, solar plants or power stations for energy generation are likewise covered by the term technical plant. 
     If operators and project planners of the control system or of the technical plant are not “synchronized”, because they are at different locations, for example, or cannot reach each other for other reasons, it can occur that, through the non-synchronized loading of automation data at the operator station server, the operator in the middle or error handling or a critical optimization loses control of the operation and monitoring of the technical plant, and the plant can suffer damage thereby. Moreover, it is possible that the operator station server itself is currently in a situation in which a loading can lead to problems (for example, with a threat of overloading or exceeding the processing capacity of the operator station server). 
     An “operator station server” in the present case is understood to mean a server that acquires data of an operating and monitoring system and also as a rule alarm and measured value archives of a control system of technical plant centrally and makes it available to users. As a rule, the operator station server establishes a communication link to automation systems (e.g., an automation device) of the technical plant and passes on data of the technical plant, which is used to for operation and monitoring of an operation of the individual functional elements of the technical plant to what are known as “operator station clients”. 
     The operator station server itself can have client functions available to it in order to access the data (archive, messages, tags, variables) of other operator station servers. This enables images of operation of the technical plant to be combined at the operator station server with variables of other operator station servers (server-server communication). The operator station server can, without being restricted thereto, involve a SIMATIC PCS 7 Industrial Workstation Server made by SIEMENS. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention is to provide a control system for a technical plant that makes it possible to operate and modify the technical plant with a high availability. 
     This and other objects and advantages are in accordance with the invention by a control system for a technical plant, in particular a production or process plant, and by a method for operating the technical plant with the control system in which an operator station server of the control system is configured to refuse to receive or process an automation configuration for the operation and monitoring of the technical plant, for a specific period of time, if an abort condition is present. 
     The automation configuration, which can be created by the computer-implemented design tool at the engineering station server, serves to operate and monitor the technical plant. The automation configuration can, for example, comprise plant mimic diagrams, which the operator station server can transmit after receiving them to a separate operator station client for visual presentation to an operator of the technical plant. In such cases, the plant mimic diagrams usually involve operating images used for control systems, which comprise graphical representations of individual elements of the technical plant and serve to show a status of the individual elements, of a (process-engineering) relationship between the elements or the like. 
     The plant mimic diagrams, in such cases, can comprise an alarm message display. This can, for example, deliver, in a tabular listing, an overview of the alarm messages arising in the control system. The overview is also referred to as a message sequence display. 
     In accordance with the invention, the operator station server is configured, when an abort condition is present, to interrupt the receipt of the new or updated automation configuration from the engineering station server or the processing of the automation configuration for a specific period of time. This enables the threat of an overload of the operator station server and/or an interruption of the operation and monitoring of the technical plant to be prevented. This advantageously enables the availability of the operation and monitoring of the technical plant to be increased. 
     Preferably, the operator station server is configured to inform the engineering station server about the refusal of the receipt or the processing of the automation configuration. The operator station server can, for example, notify the engineering station server that it cannot receive or process any automation configuration for the specific period of 10 minutes. The operator station serve can also notify engineering station server that a size of the automation configuration may not exceed a certain amount or the like. 
     Especially preferably, the operator station server is configured to inform an operator of the technical plant about the refusal of the receipt or the processing of the automation configuration. Here, the operator station server can also notify the operator, for example that, for a specific period of 10 minutes, he cannot receive or process any automation configuration or the like. 
     Within the framework of an advantageous embodiment of the control system the operator station server is configured to generate an alarm message that includes information about the refusal of the receipt or of the processing of the automation configuration by the operator station server. This alarm message can be provided in the alarm message display (message sequence display) of the control system of all participants affected by the interruption (project planners, operators etc.). The operator of the technical plant is preferably provided with the alarm message by an operator station client (visually), which the operator uses for operation and monitoring of the technical plant. 
     Preferably, the operator station server is configured to automatically establish the presence of the abort condition (i.e., without intervention by the operator or other persons). This preferably occurs via recognition of a possible overloading of the operator station server by the receipt of the automation configuration from the engineering station server or by the processing of the automation configuration. Here, the operator station server compares its present load or its present free resources with the extra load to be expected through the receipt (or processing) of the new or updated automation configuration, in order to create a forecast relating to a potential overload. 
     In particular, the operator station server is configured in this case to also automatically establish an end of the specific period of time. This preferably occurs via recognition of the removal of a possible overload of the operator station server through the receipt of the automation configuration from the engineering station server or through the processing of the automation configuration. 
     In an advantageous embodiment of the invention, the operator station server is configured to be notified of the presence of the abort condition by an operator of the technical plant during operation and monitoring of the technical plant. If, for example, the operator is merely undertaking optimizations, dealing with error handling or undertaking operating actions or the like, which may not be interrupted until they are completed, then the operator can manually define a loading restriction (temporary receipt refusal) or a processing restriction of the operator station server. After completion of his work, the operator can remove the restriction again. 
     An operator station client, which the operator can use for operation and monitoring of the technical plant, can be logged into different operator station servers, within the framework of an advantageous development of the operator station server. As a result, it is possible to derive which (additional) operator station servers must be affected by the restriction. If, for example, the operator with the operator station client is logged into a first operator station server and changes the parameters of a closed-loop controller that is located in the process image of a second operator station server, both the first and also the second operator station server must be included in the restriction. 
     Preferably, the operator station server is configured to be notified about the end of the specific period of time by the operator of the technical plant during operation and monitoring of the technical plant. 
     It is a further object, moreover, to provide a method for operating a technical plant with a control system, in particular a process or production plant, which has an operator station server and an engineering station server, where the engineering station server comprises a computer-implemented design tool via which an automation configuration for an automation of the technical plant can be created, and where the engineering station server is configured to transmit the automation configuration for an operation and monitoring of the technical plant to the operator station server, and w where the operator station server, if an abort condition is present, refuses a receipt or a processing of the automation configuration for the operation and monitoring of the technical plant for a specific period of time. 
     Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The characteristics, features and advantages of this invention described above and also the manner in which these are achieved will be explained in a clearer and easier to understand way in conjunction with the description given below of an exemplary embodiment, which is explained in greater detail in conjunction with the drawings, in which: 
         FIG. 1  shows a schematic diagram of a control system in accordance with the invention; 
         FIG. 2  shows a plant mimic diagram for operation and monitoring in accordance with an embodiment of the invention; 
         FIG. 3  shows the plant mimic diagram of  FIG. 2  in accordance with an alternative embodiment of the invention; and 
         FIG. 4  is a flowchart of the method in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE RELATED ART 
     Shown in  FIG. 1  is a part of an inventive control system  1  of a technical plant embodied as a process plant, i.e., as a process engineering plant. The control system  1  comprises a first operator station server  2  and an engineering station server  3 . Moreover, the control system  1  comprises a second operator station server  4 , an operator station client  5  and an engineering station client  6 . 
     The first operator station server  2 , the engineering station server  3 , the second operator station server  4 , the operator station client  5  and the engineering station client  6  are linked to each other via a terminal bus  7  and optionally to the further components of the control system  1  such as a process data archive (not shown in the figure). 
     For the purposes of control and monitoring, a user or operator can access the first operator station server  2  or the second operator station server  4  via the operator station client  5  over the terminal bus  7 . A project planner, in the course of engineering or project planning of an automation of the process plant, can access the engineering station server  3  via the engineering station client  6  over the terminal bus  7 . The terminal bus  7 , without being restricted thereto, can be formed as an Industrial Ethernet, for example. 
     The first operator station server  2  has a device interface  8 , which is linked to a plant bus  9 . With this device interface  8 , the first operator station server  2  can communicate with an automation device  10  and also with further components of the process plant optionally present. The plant bus  9 , without being restricted thereto, can be formed as an Industrial Ethernet, for example. The automation device  10  can be linked to any given number of subsystems (not shown). The engineering station server  3  likewise has a device interface  11  to the plant bus  9  and to the components linked thereto, such as the automation device  10 . 
     Implemented on the first operator station server  2  are a data management service  12 , a visualization service  13  and a process image  14 . Also implemented on the first operator station server  2  are a load restriction service  15  and a distribution service  16 . Implemented on the engineering station server  3  are a design tool  17  and a compilation service  18 . 
     Described below is the execution sequence of an inventive method: The project planner, with the aid of the computer-implemented design tool, implements an automation configuration  19  for an automation of the process plant at the engineering station server  3 . The automation configuration  19  serves above all in this case to enable measurements to be automated with the individual process components and also enables the process components to be controlled and regulated. A communication between the individual process components can also be determined by the automation configuration. The automation configuration  19  is placed by the compilation service  18  of the engineering station server  3  into formats that the first operator station server  2  or the automation device  10  can process. 
     The automation configuration  19  is subsequently transmitted from the engineering station server  3  to the first operator station server  2 . The transmission to the automation device  10  will not be further discussed below. The load management service  12  checks in this case whether the automation configuration  19  is to be received by the first operator station server  2  or whether the receipt is to be refused for a specific period of time. As an alternative, the load management service  12  can also initially allow a transmission of the automation configuration  19  to the first operator station server  2  but prevent a processing of the automation configuration  19  for a specific period of time. The automation configuration  19 , although thus physically located on the operator station server  2 , is not put into use and is thus without effect. 
     The prevention of the receipt or processing of the automation configuration  19  is undertaken by the load management service  12  on the instruction of the load restriction service  15 . This triggers the load management service  12  when an abort condition is present. The presence of the abort condition can be established automatically by the first operator station server  2  itself. To this end, it can check, for example whether, through the acceptance and/or the processing of the automation configuration, a potential overload situation would be produced for the first operator station server  2 . 
     The abort condition can, however, also be predetermined by the operator. To this end, the operator can make a corresponding request to the load restriction service  15  of the first operator station server  2  through the operator station client  5 . In this case, the operator can predetermine, for example, that for the period of 30 minutes no (new/updated) automation configuration  19  is to be processed by the first operator station server  2 , in order not to interrupt the operator, for example, while they are performing a critical task. 
     The end of the period of time cannot only be predetermined by the operator. Instead, the first operator station server  2  can establish the end of the period of time itself, i.e., automatically by, for example, creating forecasts with regard to the load on its resources or by having them created and taking these into account in determining the end of the period of time. The load restriction service  15  can access the diagnostic messages of central processing units (CPU) of the operator station server  2  that are stored in the process image  14 . The reason for an abort condition can also lie in the fact that a high number of process alarms are present in the process image  14  (i.e., are active) and therefore a processing or a receipt of the automation configuration is not sensible at present. 
     When the load management service  12  is to interrupt the receive process or the processing process for the specific period of time, the load restriction service  15  creates an alarm message in parallel thereto, which is stored in the process image  14  of the first operator station server  2 . The project planner and the operator have access to this alarm message (in the form of a message sequence display on the operator station client  5 ). 
     Shown in  FIG. 2  is plant mimic diagram  20 , which is displayed to the operator via the operator station client  5 . In the right-hand lower area of the plant mimic diagram  20  it is displayed to the operator, in the form of an unlocked padlock symbol  21 , that there is currently no restriction taking place on the receipt or processing of a new or updated automation configuration  19 .  FIG. 3  shows a locked padlock symbol  22  for the opposite case, i.e., a restriction is occurring. 
     An operator station client  5  can be logged into different operator station servers  2 ,  4  and through the distribution all process objects can still be accessible for operation and control. As a result, a restriction localization service  23  is moreover implemented on the first operator station server  2 . This establishes which operator station servers  2 ,  4  are affected by the restriction of the receipt/processing. If, for example, the operator is logged in with the operator station client  5  at the first operator station server  2  and changes the parameters of a closed-loop controller, which is located in a process image (not shown) of the second operator station server  4 , then both the first operator station server  2  and also the second operator station server  4  must be included in the restriction. The restriction localization service  23  transfers this information to the load restriction service  15 . This now causes the data management service  12  of the first operator station server  2  and a data management service of the second operator station server  4  (not shown) to perform the requested restriction, until this is revoked, such that, for example, the operator can bring a critical task to an end. 
     Overall, a contribution to a higher availability of the technical plant can be made by the disclosed embodiments of the invention, specifically when a web-based control system  1  is used. 
       FIG. 3  is a flowchart of the method for operating a technical plant with a control system  1  including an operator station server  2 ,  4  and an engineering station server  3  comprising a computer implemented design tool  17  via which an automation configuration  19  for an automation of the technical plant is creatable. 
     The method comprises transmitting, by the engineering station server  3 , the automation configuration  9  to the operator station server  2 ,  4  for operating and monitoring the technical plant, as indicated in step  410 . 
     Next, the operator station server  2 ,  4  refuses to receive or process the automation configuration  19  for the operation and monitoring of the technical plant, for a specific period of time, if an abort condition is present, as indicated in step  420 . 
     Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the methods described and the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.