DE102016121542A1 - Sequence control of program modules - Google Patents

Abstract

The present invention relates to a method for scheduling program modules 21, 31, 32, 41. In the method, providing a controller 50, providing a description file having a configuration for controlling a program flow is provided. Furthermore, the method comprises providing a plurality of program modules 21, 31, 32, 41, which are executable by a real-time operating system, wherein the program modules 21, 31, 32, 41 are created using one or different programming languages. Furthermore, the method has a triggering of selected program modules 21, 31, 32, 41 by executing specifications in the description file by the control device 50.

Description

The present invention is in the field of automation technology, in particular industrial automation technology, and relates to a method for scheduling program modules. Furthermore, the present invention relates to a real-time operating system, a control unit, a control device and a computer program product.

In the field of automation technology, a change is foreseen that goes from the use of classical programming languages to the use of high-level languages.

So far, for example, the standard IEC 61131 regulates the syntax and semantics of programming languages for programmable controllers. A unified suite of programmable controller programming languages is proposed. This suite has two text languages (Instruction List and Structured Text) as well as two graphical languages (Ladder Diagram and Function Block Diagram). Further, the IEC 61131 standard defines features that facilitate communication between program controllers and other components of an automated system.

Current topics, such as Industry 4.0, the Internet of Things or Agenda CPS of the VDI, show that in the future automated systems will be characterized by a high proportion of networking and software. There will be a change from classical IEC 61131-3 programming to modern high-level languages. By the year 2018, the code used should be around 70% outside the languages defined by IEC. The existing requirements, such as real-time capability and consistency, are supplemented by greater flexibility, more security and better maintainability.

Also in the production of programmable logic controllers and / or runtime environments, therefore, there are technical changes in the future.

EP 2 504 738 B1 describes a control method and method for executing multiple programs on multiple parallel processing devices. In this case, a time signal generator is assigned to each of a plurality of parallel processing devices, at the expiration of which a control method for executing programs is executed on the associated processing device.

However, the use of a time signal generator has the disadvantage that the speed of processing data in a real-time operating system can be reduced.

It is an object of the present invention to provide a solution to improve schedulers for real-time operating systems.

This object is achieved by the features of claim 1. Furthermore, the object is achieved by a real-time operating system according to claim 13, a control device according to claim 14, a control device according to claim 15 and a computer program product according to claim 16. Further embodiments emerge from the subclaims.

In the method according to the invention for scheduling program modules, it is provided to provide a control device and to provide a description file comprising configuring the description file for controlling a program sequence. Furthermore, the method comprises providing a plurality of program modules that can be executed by a real-time operating system, wherein the program modules are created using one or different programming languages. Furthermore, the method has a triggering of selected program modules by executing specifications in the description file by the control device.

The control device can be designed as an execution and synchronization manager or execution and synchronization manager (ESM).

By using such a controller, equivalent treatment of programs of different programming domains is enabled.

For example, program modules can be executed which are each programmed in at least one of the programming languages according to the IEC 61131 standard, in Matlab / Simulink, C ++, C # or JAVA or Python. Other programming languages are also possible. According to the standard IEC 61131 (Edition 3.0, 2013-02) two textual languages are used, namely Instruction List (IL) and Structured Text (ST) and two graphical languages, namely Ladder Diagram (LD) and Function Block Diagram (FBD) given. These programming languages can be used together with programming languages in a sequence control.

The control device allows a simple configuration of IEC 61131-3-like tasks, which allows the integration of program instances of different programming languages. Therefor The controller uses a number of operating system processes and threads to enable high-performance integration into the underlying real-time operating system.

Thus, a single programming language can be used for all program modules. It is also possible that different programming languages are used for two or more program modules.

When the program modules are triggered, the description file, which can also be called a configuration file, is no longer addressed. Such a response would take too much time and slow down the processing. Rather, the configuration file (s) is read at system startup and only executed during the execution phase. In this case, an execution of the information from the description file is provided by the control device. Thus, there are specifications for the execution of the program modules by the contents of the description file. These presets are provided by configuring the description file. Consequently, the program modules are triggered by executing configuration defined in the description file.

The program modules are controlled, for example, by means of a programming interface, in particular with an API (API = application programming interface). The description file, which can be provided, for example, as an Extensible Markup Language (XML) file, is used to configure when the programs are addressed and executed. With the aid of the control device, program modules can be executed and status information on the program sequence, e.g. Tasklaufzeiten, are recorded.

The controller can itself be initialized and controlled by a PLC manager (PLC = Programmable Logic Controller). This sets e.g. the controller in RUN / STOP and reboots. During operation, the controller is cyclically triggered by events (software or hardware) to execute an execution logic.

Also, a variety of description files or configuration files can be used for flow control. Additional description files may include a configuration of additional task and its associated program modules. For example, a description file could describe, for example in the form of an XML file, a main task (task main), another description file a control task (task crtl) and another description file a synchronization task (task sync). The configuration files can be easily merged into one configuration, if there are no contradictions. For this reason, the control device or a control device in the function of a master (ESM master) should know and read in all configurations.

In a preferred embodiment, the method comprises a multiple triggering of at least one of the program modules by the control device.

A response of the description file is not necessary for this, so that processing times can be kept short. Other task types or task types such as Event and Idle Task can also be supported. The description file or the plurality of description files are advantageously read only for initial configuration, but not during execution.

In a further preferred embodiment of the method, it is provided that the control device is designed to trigger at least some of the program modules such that they can be executed in different processes managed by the real-time operating system.

In this way it is possible to use only the program modules that are needed and also to execute processes in parallel to efficiently use time resources.

In a development of the method, it is provided that the real-time operating system is designed to execute the processes and / or program modules as a function of predetermined priorities.

By setting priorities, control tasks can be edited according to their importance or urgency.

Furthermore, in one embodiment of the method, a recording and evaluation of the sequence control by the real-time operating system can be provided.

For recording and evaluation additionally introduced marker points can be recorded and statistics are formed.

In another embodiment, the method may provide for extending the scheduling by an additional program module without rebooting a control system.

A control system refers to a flow control in the program modules typically loaded, started, debugged, stopped and unloaded. The control system is based on the real-time operating system.

It is advantageous that an extension of the control system is possible without having to interrupt the control system for a restart. In this way, the operation can be continued continuously.

In a further embodiment, the method may include partitioning the scheduler to different processes.

Such a distribution may take advantage of different processes of the real-time operating system, e.g. Memory protection mechanisms, better exploit.

Furthermore, in another embodiment of the method, it is possible to provide statistical analysis using profiling information.

In this case, marks or markings can be introduced in the control device in order to generate the profiling information. Profiling information is information for analyzing the runtime behavior of software. Thus, statistical data can be evaluated to improve process control and used for statistical purposes.

In a further embodiment, the method comprises introducing at least one recording mark into a program module for providing an application diagnosis.

A recording mark can be understood as a position in a program module which makes it possible to obtain information about its execution over a specific part of a program module. Based on this information, a diagnosis can subsequently be made in order to evaluate the executed application. This can be a single application or the entire application of the tax task.

In a further embodiment, the method comprises using the control device as a master and providing at least one further control device as a slave, which is subordinate to the control device as a master.

The use of a slave can be used advantageously when a program module is to be executed in another process. If the entire application runs in a single process, a slave can be dispensed with.

Tasks or tasks are an organizational unit for executing programs. OS processes and OS threads (OS = operating system or operating system) can be used for the technical realization of these organizational administrative units. It is desirable to enable a synchronized execution of tasks across OS process boundaries. The master is generally unable to create OS threads in other OS processes. For this reason, this can be taken over by a slave in each participating OS process. The execution of the programs or program modules can be carried out by the master. If, however, only one OS process is used, all programs and threads can be executed without slaves.

For example, the master and the slave can communicate via interprocess communication if they are running on the same device. The communication is advantageously realized at the lowest level with basic functionalities of the operating system. If the master and the slave run in different devices, these devices can be coupled with each other via a data connection.

Furthermore, in a further preferred embodiment, the method may comprise assigning individual tasks defined in the description file to program modules by the control device.

Thus, the controller may distribute individual tasks within the control system, for example, to improve the utilization of the control system. A task or a plurality thereof may be a subset of a process within a control task.

Furthermore, the object of the present invention with a real-time operating system for the flow control of program modules comprising a control device is achieved. Here, the real-time system has a stored in a memory device description file that defines a program flow. Furthermore, a plurality of program modules executable by the real-time operating system are provided, which are created using one or different programming languages, wherein the control device is designed to trigger the program modules by executing specifications of the description file.

The real-time operating system (RTOS) is an operating system that is capable of meeting real-time application requirements. Here, the adherence to defined response times in the field of Automation technology of particular importance to prevent damage to an installed and controlled system.

The object of the present invention is achieved with a control device for the sequence control of program modules of one or different programming languages in a real-time operating system. For this purpose, the control device has a processor and a memory for carrying out the method according to the invention.

The control device can be designed in the form of an execution and synchronization manager or execution and synchronization manager (ESM). The controller may prioritize centralized tasks of the controller, distribute to existing program modules and receive information from the individual program modules and analyze this information.

Furthermore, the object of the present invention is achieved by a control device for the sequence control of program modules of different programming languages in a real-time operating system. For this purpose, the control device has a control device according to the invention, a processor, a memory, and at least one interface to an automation device.

In this case, a control device may be a control device which is installed in an automation system. Here, the control device according to the invention is part of the control device according to the invention. A distribution of the control device to a plurality of computer cores or cores of a multi-core processor is also possible.

Furthermore, the object of the present invention is achieved with a computer program product. For this purpose, the computer program product has program code means for carrying out the method according to the invention, wherein the computer program product runs on a computer system in a real-time operating system.

The computer program product can be, for example, a data carrier which is made available in an automation system in order to carry out the method according to the invention.

Overall, the proposed control technology offers a flexible solution that can dynamically adapt to the future development in the field of automation technology. The proposed control architecture allows by its openness, in contrast to previously closed systems, individually implement the desired applications and still set up on a stable basis. This can be ensured not only for the target group of high-level language programmers, but also for existing installed automation systems in the environment of IEC 61131-3 programming.

• 1 ein Ausführungsbeispiel zur Steuerung einer Gesamtapplikation in einer Automatisierungsanlage gemäß der vorliegenden Erfindung;
• 2 ein Ausführungsbeispiel der vorliegenden Erfindung eines schematischen Aufbaus mit einer Steuereinrichtung als Master und zwei weiteren Steuereinrichtungen als Slave; und
• 3 ein Ausführungsbeispiel gemäß der vorliegenden Erfindung einer Steuerung eines Programmablaufs durch eine Steuereinrichtung.

Some embodiments of the invention are shown purely schematically in the drawings and will be described in more detail below. It shows:

• 1 an embodiment for controlling a total application in an automation system according to the present invention;
• 2 An embodiment of the present invention of a schematic structure with a control device as a master and two other control devices as a slave; and
• 3 An embodiment according to the present invention, a control of a program flow by a control device.

1 shows an embodiment for controlling a total application 10 in an automation system according to the present invention.

In this context, a complete application is understood as meaning all programs or program modules, tasks or tasks and configuration settings that are required for execution on a control device. It is not relevant whether the controller or the controller is the only one or one of several devices.

Typical for automation is the cyclic execution of programs or program modules. Feedback to the user or user is typically not given during these cycles.

In 1 is a schematic structure of three tasks 20 . 30 . 40 or tasks, which in total four programs or program modules 21 . 31 . 32 . 41 from the domains IEC 61131-3, C ++ and Matlab / Simulink synchronized. The program module 21 is a CPP filter and programmed in the C ++ programming language. The program module 31 is an IEC Prepare program and programmed in one of the programming languages according to IEC standardization. The program module 32 is a SIM-CTRL program, ie a control program, and is programmed in the programming language Matlab / Simulink. The program module 41 is an IEC sync program, ie a synchronization program, and is programmed in one of the programming languages according to IEC standardization. In this context, the terms "program" and "program module" are used interchangeably.

After the procedure end or end of the program module 30 is via an interface 33 via a communication connection 34 the task 40 with the program module 41 causes to start.

The tasks 20 . 30 . 40 of the 1 have to execute the entire application 10 different priorities, with the task 20 the main task or main task has the lowest priority, the task 30 has a medium priority as the control task or Ctrl task and the task 40 as event task or event task with synchronization tasks has the highest priority. Further assigns the task 20 a cycle time of 5 ms (ms = milliseconds), and the task 30 of 30 ms up. The task 40 is executed once and ends when the program module 41 or the program is executed in the program module (event: proc_end).

2 shows an embodiment of the present invention of a schematic construction with a control device 50 as master, a controller subordinate to the master 60 as the first slave and another control device subordinate to the master 70 as a second slave. Here, the master component and slave components become 50 . 60 . 70 used to coordinate program modules from different program domains in different processes. Furthermore, in 2 different operating system processes or OS processes 11 . 12 . 13 shown, each OS threads 14 . 15 . 16 . 17 . 18 exhibit.

The procedure according to the invention allows the composition of heterogeneous task contents. The execution order within a task is freely selectable, not specified by the system, and a consistent exchange of data between program instances is possible.

The configuration of the master 50 and his tasks 20 . 30 . 40 is done by one or more description files, here in the form of one or more XML files that allow configuration rather than programming. This allows the function of a system to be changed at runtime without having to recompile the individual application parts. Also, the description file or the XML-based configuration allows the user to make adjustments directly to the controller or to use their own external tools and toolchains.

The structure of the description file, in particular in the form of an XML file, can be specified by clearly defined schema files, which allows a quick check of the configuration. The specification of tasks and the associated program instances in several description files or XML configuration files allows the distribution of the entire application 10 into functional modules that can be created by different developer groups or suppliers. This not only facilitates the development of complex plant control, but also the gradual expansion of a running plant. Thus, the entire application 10 are not available from the beginning, but can be composed of sub-modules.

Every task 20 . 30 . 40 can also be assigned to a processor core, a group or all processor cores of the controller by defining parameters in the description file or XML file.

A flexible system of master and slave components 50 . 60 . 70 also allows the user to run programs across process boundaries. This is an advantageous prerequisite for the separation of programs of different users, which are thus executed in encapsulated memory areas. The memory protection mechanisms of the underlying real-time operating system can serve as the basis for this. For security reasons, it is thus possible to restrict the access of programs or program modules according to the user rights.

In 2 configured the master 50 via active compounds 51 . 52 one program module each 21 . 41 a slave 60 . 70 , Here, configure refers to the provision of priority information by the master 50 , Furthermore, in 2 communication links 53 . 54 . 57 . 58 exists to switch between each program module 21 . 31 . 32 . 41 and a task 20 . 30 . 40 Exchange commands and information or feedback. Here, the information between master and slave instances are sent back and forth respectively received. For example, commands are trigger commands ("triggers off") from the task 20 . 40 to the program module 21 . 41 , For example, feedback is provided by the program modules 21 . 41 to the tasks 20 . 40 sent ("reports"). Furthermore, tripping orders ("triggers off") also depend on the task 30 each to the program modules 31 . 32 over the communication links 55 . 56 sent, with the communication taking place within an OS thread.

With the proposed approach, it is possible to transfer the known tasks from the IEC standardization in the high-level language world. Therefore, the controller currently supports cyclic tasks, idle tasks, and event-based tasks that rely on the priority-driven processes and threads of the real-time operating system. In addition to this priority-driven execution, the controller also enables task execution in response to the occurrence of a particular event. With this freely configurable system, it is therefore possible to mix program instances of different programming domains within a task and to execute them together. This opens the process models known from IEC 61131-3 for other domains as well.

By the degrees of freedom, the task execution with the control device 50 however, the complexity of configuration and analysis also increases. Therefore, the controller provides 50 integrated mechanisms for a detailed profiling based on available extensions of the real-time operating system. The user thus has the opportunity to observe, evaluate and record different properties of the task execution and of the operating system. These properties include tasks and program execution times, frequency of task evictions, latency and jitter, system load, or watchdog monitors. This information can be evaluated with the help of dynamic ring buffers also for analyzes post-mortem after an error case.

In addition, the central storage of the profiling information of the control device 50 the ability to perform statistical evaluations or to provide this data for further analysis via remote server services.

3 shows an embodiment according to the present invention, a control of a program flow by a control device 50 , The control device 50 can also access auxiliary instances to perform an automation task, such as a slave or multiple slaves, as in 2 shown.

3 shows a simplified representation of a coordination or control of control tasks by a control device 50 as they are for example in 2 is shown. Here are the tasks described 20 . 30 . 40 of the 1 by the control device 50 controlled. In this control or its evaluation can be clearly understood when the individual programs and tasks are displaced by higher processes. These higher processes are reserved for the operating system and as OS processes 19 in 3 shown.

3 shows the time on the x-coordinate and the process or priority of the process on the y-coordinate. Thus, as already too 1 explains the task 20 the lowest priority and the task 40 the highest priority. With RTOS is a high priority thread 90 of the real-time operating system (RTOS), which has the highest priority. The high priority thread 90 or high priority OS-Thead 90 is therefore part of the real-time operating system.

Thus, the first task will be in time 20 with the program module 21 executed, but through a real-time process 19 of the operating system is interrupted. Thereafter, the task is carried out 30 with the program modules 31 and 32 , After that, the task becomes 40 with the program module 41 processed. Again, there are temporal interruptions of the program modules through real-time processes 19 , After processing the higher priority, the task starts again 20 and then the task becomes 30 executed, allowing a cyclic processing of tasks in 3 is hinted at.

Overall, according to the invention, functionality is made possible as part of a new firmware architecture, on the basis of which new industrial controls are realized. This architecture is initially implemented for use on a device or control unit. However, the architecture is designed to extend to multiple devices. This is the case, for example, in a redundancy system where two controllers are synchronized with each other.

The aim here is to support the addition of classical programming of controllers to high-level languages. For this purpose, a smooth transition between IEC 61131-3 and the high-level language world is sought. The prerequisite for this, in addition to the support of such languages, is the seamless integration of the different programming domains. These include Matlab / Simulink, C ++, C #, JAVA, Python and the languages of IEC 61131-3. For such seamless integration, the controller should be able to transfer the process known from IEC 61131-3 with program instances and tasks into the flow of the other programming domains. Despite these more complex requirements for technical implementation, additional aspects of data security, usability, flexibility and, above all, efficiency are guaranteed.

LIST OF REFERENCE NUMBERS

10

overall application

11

OS process

12

OS process

13

OS process

14

OS thread

15

OS thread

16

OS thread

17

OS thread

18

OS thread

19

OS process

20

Task or task

21

program module

30

Task or task

31

program module

32

program module

33

end of procedure

34

Communication Interface

40

Task or task

41

program module

50

Control device or ESM

51

operatively connected

52

operatively connected

53

communication link

54

communication link

55

communication link

56

communication link

57

communication link

58

communication link

60

first slave

70

second slave

80

OS process

90

high-priority OS thread

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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

• EP 2504738 B1 [0006]

Claims (15)

Method for sequential control of program modules (21, 31, 32, 41) comprising Providing a control device (50), Providing a description file comprising a configuration for controlling a program flow, Providing a plurality of program modules (21, 31, 32, 41) executable by a real-time operating system, the program modules (21, 31, 32, 41) being created using one or different programming languages, and Triggering selected program modules (21, 31, 32, 41) by executing defaults in the description file by the controller (50). Method according to Claim 1 , further comprising multiple triggering of at least one of the program modules (21, 31, 32, 41) by the control device (50). Method according to Claim 1 or Claim 2 , characterized in that the control device (50) is designed to trigger at least some of the program modules (21, 31, 32, 41) such that they can be executed in different processes managed by the real-time operating system. Method according to Claim 3 , characterized in that the real-time operating system is adapted to execute the processes and / or program modules (21, 31, 32, 41) in dependence on predetermined priorities. Method according to Claim 4 further comprising recording and evaluating the scheduling by the real-time operating system. The method of any one of the preceding claims, further comprising altering the scheduling by adding or removing program modules without rebooting a control system. The method of any one of the preceding claims, further comprising distributing the scheduler to various processes. The method of any preceding claim, further comprising generating a statistics score using profiling information. Method according to one of the preceding claims, further comprising introducing at least one recording mark into a program module (21, 31, 32, 41) for providing an application diagnosis. Method according to one of the preceding claims, further comprising Using the controller (50) as master and Providing at least one further control device (60, 70) as a slave, which is subordinate to the control device (50) as a master. The method of any one of the preceding claims, further comprising assigning individual tasks defined in the description file to program modules (21, 31, 32, 41) by the controller (50). Real-time operating system for scheduling program modules (21, 31, 32, 41) comprising a control device (50), a description file stored in a memory device, which defines a program sequence, a plurality of program modules (21, 31, 32, 41) executable by the real-time operating system and constructed using one or different programming languages, wherein the control means (50) is adapted to execute the program modules (21, 31, 32, 41) by executing Define specifications in the description file. Control device (50) for scheduling program modules (21, 31, 32, 41) of one or different programming languages in a real-time operating system comprising a processor and a memory for carrying out the method according to one of Claims 1 to 12 , Control device for sequencing program modules (21, 31, 32, 41) of one or different programming languages in a real-time operating system comprising a control device (50) Claim 14 ; a processor, a memory, and at least one interface to an automation device. Computer program product with program code means for carrying out the method according to one of Claims 1 to 12 wherein the computer program product runs on a computer system in a real-time operating system.

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