WO2007075097A1

WO2007075097A1 - Processing unit and method for configuring a networked automation system

Info

Publication number: WO2007075097A1
Application number: PCT/RU2005/000667
Authority: WO
Inventors: Ahmad-Ramez Madjed Kassou; Georgy Artemievich Martsinovsky; Boris Piwinger
Original assignee: Siemens Aktiengesellschaft
Priority date: 2005-12-26
Filing date: 2005-12-26
Publication date: 2007-07-05
Also published as: EP1966660A1

Abstract

The invention relates to a processing unit (1) and a method for configuring a networked automation system. To allow automated configuration of the automation system, it is proposed that the processing unit (1) has first mean for ascertaining components suitable for performing an automation task from components of the automation system which are networked to one another, and second means for allocating the automation task to at 15 least one of the suitable components .

Description

Processing unit and method for configuring a networked automation system

The invention relates to a processing unit and a method for configuring a networked automation system and to an automation system having such a processing unit.

The invention is used in the field of industrial automation, for example.

In today's product and process automation systems, process- engineering installations are normally controlled using programmable logic controllers which have a CPU suitable for executing a control program. Depending on the complexity of the process to be controlled, an automation system also has a plurality of programmable logic controllers (PLC) coupled to one another. To control the various automation processes, this involves providing a plurality of CPUs and hence increasing the hardware resources.

The various automation devices communicate with the programmable logic controllers normally using input/output assemblies. The input/output assemblies convert the field signals detected' on the installations using sensors, for example, into a form suitable for a system bus or for a programmable logic controller connected to the system bus. Such input/output units themselves frequently have a dedicated CPU.

To configure such automation systems, engineering systems are normally used today which configure the automation system from a superordinate level. The automation tasks needed for performing the required automation process are distributed over the intelligent components which are present in the automation system, such as the programmable logic controllers, the intelligent input/output units or other units equipped with a CPU, using the engineering system. With this configuration of the automation system, the user of the engineering system will take account of the hardware resources of the intelligent components provided in the automation system in order to achieve an optimum utilization level for the overall system.

The invention is based on the object of allowing automated configuration of an automation system.

This object is achieved by a processing unit for configuring a networked automation system, having first means for ascertaining components suitable for performing an automation task from components of the automation system which are networked to one another, and second means for allocating the automation task to at least one of the suitable components.

This object is also achieved by a method for configuring a networked automation system, having the following method steps : components suitable for performing an automation task are ascertained from components of the automation system which are networked to one another using a processing unit, and the automation task is allocated to at least one of the suitable components using the processing unit.

The invention is based on the insight that many industrial ■processes and many industrially manufactured products are frequently subject to changing specifications and conditions, which mean that the relevant control tasks also frequently need to be changed. In such cases, the automation system normally needs to be reconfigured. The control programs running on the programmable logic controllers need to be updated and, depending on the complexity and available hardware resources, redistributed over the various intelligent components of the automation system. The necessary reconfiguration of the automation system can be performed very quickly and efficiently using the inventive processing unit.

In this context, the first means in the processing unit are able to take the various networked components of the automation system and filter out suitable components which have means suitable for performing the automation task. To this end, the first means in the processing unit check which of the components networked in the automation system have the hardware required for performing the automation task, for example. Such an aspect can be ascertained, by way of example, by virtue of the first means being used to search through a list, stored in the processing unit or in an appropriate memory, within which the individual components and their hardware are listed. Alternatively,, the first means may be in a form such that they read in appropriate data directly from the individual components of the automation system upon request.

If the automation system is found to contain a component which can undertake, the required automation task, the second means is used to transfer the automation task to this component. If the first means find a plurality of components which can undertake the required automation task, the processing unit can use further criteria to determine the most suitable component.

A crucial advantage which results from the invention is that the inventive processing unit allows more or less system- inherent redundancy in the automation system without this requiring particularly cost-intensive hardware-related measures to be taken. If a component of the automation system fails which is concerned with performing an automation task, the inventive processing unit can immediately be used to activate a replacement component for performing this. automation task. This prevents system failure in a particularly inexpensive and elegant way.

Alternatively, the processing unit can also allocate the automation task to two or more components of the system directly, so that the automation task or an appropriate control program is running in parallel on two intelligent components which have the necessary resources.

In one advantageous refinement of the invention, the first means are provided for checking free resources of the suitable components before the automation task is allocated. Hence, if a suitable component which, in principle, has suitable hardware means for performing the automation task is found in a first step then in this advantageous refinement of the invention the first means first of all check whether these hardware means are actually free before the automation task is allocated. Using the first means, this allows a relatively even network utilization level to be achieved. Thus, even if a plurality of suitable components for performing the automation task are ascertained, for example, it is possible to select the component which has the most free resources. The further, likewise suitable components can advantageously be reserved for redundancy purposes in order to undertake performance of the automation task if the selected component fails.

In a further advantageous refinement of the invention, the processing unit can be networked to the components of the automation system. In an automation system which is known from the prior art, a system planner would need to load the control program, e.g. using an engineering system, onto a suitable programmable logic controller installed in the automation system. In said advantageous refinement of the invention, the processing unit can be used to load such a control program automatically onto a component suitable for executing the control program. This may be a programmable logic controller, an input/output unit with an appropriate CPU or else a personal computer.

Integrating the processing unit into the networked automation system also allows dynamic updating of the control programs for the intelligent components. Such dynamic updating during a process which is in progress may be appropriate if the process changes dynamically, for example.

In a further advantageous refinement of the invention, the processing unit has third means for automatically identifying components which have just been installed in the automation system. The third means are used to implement a kind of plug and play mechanism for automation systems. When a new intelligent component with a CPU is connected to the automation system, it can be automatically identified by the processing unit and included when configuring the automation system. Thus, the control programs required for controlling the automated process can be redistributed within the automation system following the automatic identification of the recently installed component, for example. This allows automatic reconfiguration of the automation system following automatic identification of the recently installed component.

In one advantageous embodiment of the invention, the processing unit has fourth means for the controlled starting and stopping of an automation process. To reconfigure the automation system, particularly when installing new components, the automation process which is in progress normally needs to be stopped in a safe condition. The processing unit can then be used to perform the appropriate configuration and the automation process can be started again using the fourth means. When starting and stopping the automation process, the specific requirements of the automation process can be taken into account.

In a further advantageous refinement of the invention, the processing unit has fifth means for identifying and localizing faults within the automation system. When a fault is identified using the fifth means, the processing unit can stop the automation process in a controlled manner, particularly using the fourth means, and can reconfigure the automation system, which involves replacing the faulty component with another suitable component. The processing unit can then use the fourth means to start the automation process again in a controlled manner, with the automation task previously performed by the faulty component now being undertaken by the new component.

In a further advantageous embodiment of the invention, the processing unit has sixth means for performing an update for software installed on the networked components of the automation system. In contrast to systems known from the prior art, in which such an update needs to be performed manually, e.g. using an engineering system, for each individual component of the automation system, this embodiment of the invention allows the processing unit to use the sixth means to undertake automated updating of the full software installed in the automation system.

The processing unit with its previously described means mentioned within the context of the various embodiments can be implemented using standard hardware. By way of example, an embodiment of the invention in which the processing unit is in the form of a personal computer is advantageous.

The opportunity to use the processing unit to distribute automation tasks flexibly over the various components of the automation system, particularly in a dynamic manner, means that redundancy can be implemented very much less expensively in comparison with today's automation systems. By way of example, to ensure redundancy when performing control and regulation tasks, it is advantageous to have an embodiment of the invention in which the first means are provided for allocating the automation task to at least two components, with provision being made for redundant performance of the automation task on the at least^' two components, and the processing unit having seventh means for comparing data which result from the redundant performance of the automation task. In this context, it should be mentioned that purely software- based redundancy is also conceivable, in which the automation task and an appropriate control program run in the form of two entities on one and the same component. Such a concept requires far fewer resources in comparison with redundancy implemented on a hardware basis.

At this juncture it should be mentioned that there is already a certain level of redundancy for performing the automation task even when this automation task is, at one time, being performed only by one component of the automation system. If this component fails, the processing unit can immediately ascertain a replacement component in the system to undertake the relevant automation task, particularly without • interruption.

An automation system with a processing unit in line with one of the embodiments described above allows an extremely flexible and optimized utilization level for the hardware which is available in the automation system. In contrast to conventional automation systems, a large portion of this hardware may be in the form of standard hardware. By^' way of example, an embodiment of an automation system is conceivable in which the automation system comprises components suitable for performing the automation task in the form of a programmable logic controller and/or a personal computer and/or an input/output unit and/or a switch. All of said components are available with an appropriate CPU, whose power can be used very flexibly using a processing unit in line with one of the embodiments described above.

The invention is described and explained in more detail below using the exemplary embodiments illustrated in the figures, in which: FIGURE 1 shows an automation system with a processing unit for configuring the automation system based on a first embodiment of the invention, and

FIGURE 2 shows an automation system with a processing unit for configuring the automation system based on a second embodiment of the invention.

FIGURE 1 shows an automation system with a processing unit 1 for configuring the automation system based on a first embodiment of the invention. The automation system is used to control an industrial production process. Components which are required for this purpose are linked to a communication network 2. The networked components are specifically a first PC 3, a programmable logic controller 4, a second PC 5, which comprises the processing unit 1, a third PC 6, a switch 7, a first input/output unit 8 and a second input/output unit 9.

From a remote station 10 on which a web browser is installed, it is possible to access the communication network 2 in order to access the automation process in an observational or operative capacity from a remote site. To be able to implement such access using a commercially available web browser, such as Windows Internet Explorer, a web server 11 is installed on the switch 7.

An HMI system 12 (Human Machine Interface) can be used by a user to access the second PC 5, on which the processing unit 1 is installed.

The first and second input/output units 8, 9 connect the process-engineering units to the communication network 2.

The first and third PCs 3, β, the programmable logic controller 4, the switch 7 and the first input/output unit 8 have a CPU which can be used to perform automation tasks formulated as control programs. A task of the second PC 5 or of the processing unit 1 installed on the second PC 5 is optimum distribution of automation tasks or of the associated control programs over the various CPUs of the connected components. Such configuration or reconfiguration of the automation system is required, by way of example, when components have just been installed within the communication network. The reconfiguration can be triggered automatically by virtue of the processing unit 1 automatically identifying a component which has just been installed. Alternatively, such reconfiguration of the automation system may also be triggered manually using the connected HMI system 12. If the automated process is changed, for example, a user of the HMI system 12 can disconnect the automation process in a controlled manner using the processing unit 1 in order to perform appropriate reconfiguration of the system. Next, the processing unit 1 checks which of the components connected to the automation system is able to undertake a newly required automation task and the associated control program. This is done by first checking which of the connected components has the hardware prerequisites required for this purpose in principle. Hardware prerequisites are sufficient processing power and sufficient memory, for example.

Among the components which have the required hardware resources, a subsequent step is used to check which component can provide the most free resources for performing the automation task. This step makes sense in order to ensure that the network utilization level is as even as possible.

Depending on the complexity of the process which is to be automated, sometimes a large number of components are concerned with performing automation tasks. In such a case, the automation process is performed by a plurality of "PLC entities". The PLC entities are distributed over the various components using the processing unit 1, as described above, taking into account the resources which are available in the network. Thus, it is assumed in the automation system depicted in figure 1 that the first PC 3 provides a first and a second PLC entity 15, 16, the programmable logic controller 4 provides a third and a fourth PLC entity 17, 18, the switch 7 provides a fifth PLC entity 19 and the first input/output unit 8 provides a sixth PLC entity 20. The distribution of these PLC entities can be changed dynamically by the processing unit 1 in order to be able to react to altered process conditions and specifications, for example, and/or to allow for an alteration in the automation system.

The processing unit 1 has a "system manager" 13 installed on it. The system manager 13 is a software component which comprises means for ascertaining components suitable for the purpose of performing the automation task and for checking free resources of the suitable components, means for allocating the automation task to one of the suitable components, means for automatically identifying components which have just been installed in the automation system, and means for the controlled starting and stopping of the automation process. In addition, an application server 14 is installed on the processing unit 1 and provides means for performing an update for software installed on the various networked components of the automation system. Since the software for performing the automation task is distributed by the processing unit 1 centrally over the various components of the automation system which are capable of doing this, the software can also be expediently updated by the processing unit 1 using the application server 14.

The second PC 6 has an HMI entity 21 installed on it for the purpose of providing a further human machine interface. Using this software component, which was allocated to the second PC 6 likewise using the processing unit 1, a user of the second PC 6 can access the automation process in a similar manner to a user of the HMI system 12.

FIGURE 2 shows an automation system with a processing unit 1 for configuring the automation system based on a second embodiment of the invention. The automation system contains a communication network 2, to which a first and a second input/output unit 8, 9, an HMI system 12 and a switch 7 are connected, the switch 7 having a first, a second and a third PC 3, 5, 6 connected to it. In addition, the automation system has a fourth PC 22 connected to it which has a web server 11 installed on it. The fourth PC 22 also acts as a security gateway. The web server allows the automation system to be accessed from a remote station 10, on which a commercially available Internet browser is installed, via the Internet .

The automation system shown affords redundant performance of the control tasks required for performing the automated process. The actual automation task is performed by three PLC entities 15, 16, 17 in the example shown, these entities being installed both on the first PC 3 and on the second and third PCs 5, 6. The three PLC entities 15, 16, 17 process the same automation tasks in parallel, so that the three PCs 3, 5, 6 should, in principle, provide the same output values. When the automation process changes, the PLC entities 15, 16, 17 are updated by the processing unit 1. In addition, the processing unit 1 performs alignment of the data provided by the various PCs 3, 5, 6. If this process establishes that the three PCs 3, 5, 6 or the PLC entities 15, 16, 17 running on them provide different results then the processing unit 1 is used to generate an appropriate fault report. The processing unit 1 can likewise be used to localize the faulty component or the faulty PC 3, 5, 6 and to reconfigure it as appropriate .

In the automation system described here, a maximum level of redundancy can be achieved using standard hardware components. Instead of a plurality of programmable logic controllers connected in parallel, redundant PLC entities 15, 16, 17 run in parallel on various PCs 3, 5, 6. If all three PCs 3, 5, 6 provide the same results, the switch 7 or the processing unit 1 installed on it forwards the result to the appropriate components via the communication network 2.

Claims

Patent claims

1. A processing unit (1) for configuring a networked automation system, having - first means for ascertaining components suitable for performing an automation task from components of the automation system which are networked to one another, and second means for allocating the automation task to at least one of the suitable components.

2. The processing unit (1) as claimed in claim 1, where the first means are provided for checking free resources of the suitable components before the automation task is allocated.

3. The processing unit (1) as claimed in claim 1 or 2, where the processing unit (1) can be networked to the components of the automation system.

4. The processing unit (1) as claimed in one of the preceding claims, where the automation task is in the form of a control program.

5. The processing unit (1) as claimed in one of the preceding claims, where the processing unit (1) has third means for automatically identifying components which have just been installed in the automation system.

6. The processing unit (1) as claimed in one of the preceding claims, where the processing unit (1) has fourth means for the controlled starting and stopping of an automation process.

7. The processing unit (1) as claimed in one of the preceding claims, where the processing unit (1) has fifth means for identifying and localizing faults within the automation system.

8. The processing unit (1) as claimed in one of the preceding claims, where the processing unit (1) has sixth means for performing an update for software installed on the networked components of the automation system.

9. The processing unit (1) as claimed in one of the preceding claims, where the processing unit (1) is in the form of a personal computer (3, 5, 6) .

10. The processing unit (1) as claimed in one of the preceding claims, where the first means are provided for allocating the automation task to at least two components, with provision being made for redundant performance of the automation task on the at least two components, and the processing unit (1) having seventh means for comparing data which result from the redundant performance of the automation task.

11. An automation system having a processing unit (1) as claimed in one of claims 1 to 10.

12. The automation system as claimed in claim 11, where the automation system comprises components suitable for performing the automation task in the form of a programmable logic controller (4) and/or a personal computer (3, 5, 6) and/or an input/output unit (8, 9) and/or a switch (7) .

13. A method for configuring a networked automation system, having the following method steps: - components suitable for performing an automation task are ascertained from components of the automation system which are networked to one another using a processing unit (1) , and - the automation task is allocated to at least one of the suitable components using the processing unit.

14. The method as claimed in claim 13, where the processing unit (1) is used to check free resources of the suitable components before the automation task is allocated.

15. The method as claimed in claim 13 or 14, where the processing unit (1) is networked to the components of the automation system.

16. The method as claimed in one of claims 13 to 15, where the automation task is in the form of a control program.

17. The method as claimed in one of claims 13 to 16, where components which have just been installed in the automation system are automatically identified using the processing unit (1) .

18. The method as claimed in one of claims 13 to 17, where an automation process is started or stopped in a controlled manner using the processing unit (1) .

19. The method as claimed in one of claims 13 to 18, where faults within the automation system are identified and localized using the processing unit (1).

20. The method as claimed in one of claims 13 to 19, where the processing unit (1) is used to perform an update for software installed on the networked components of the automation system.

21. The method as claimed in one of claims 13 to 20, where the processing unit (1) used is a personal computer (3, 5, 6) .

22. The method as claimed in one of claims 13 to 21, where the automation task is allocated to at least two components using the processing unit (1), with the automation task being performed redundantly on the at least two components, and the processing unit (1) being used to compare data which result from the redundant performance of the automation task.