Submodule and method for exchanging peripheral data

A method for exchanging peripheral data and submodule, wherein a transfer means is embedded into an operating system of the submodule for the exchange of the peripheral data with a main module to accelerate a process of copying input/output data from a decentralized peripheral system to a superordinate level.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for the data exchange of peripheral data between a main module and a submodule, where a peripheral unit is connected to the submodule and data are read in or output using the peripheral unit.

The method comprises defining a peripheral transfer data record having a first address range of a peripheral unit and a second address range of a main module, and mapping the peripheral data prevailing in the first address range into the second address range and/or mapping the peripheral data prevailing in the second address range into the first data range.

The invention also relates to a submodule for exchanging peripheral data with a main module, comprising an operating system, an application program for implementing control tasks, and an interface, which is configured to read in data from a peripheral unit and/or output data to the peripheral unit.

2. Description of the Related Art

In the area of field buses, such as the Profibus Decentralized Peripherals (DP), methods and control systems are known in which a superordinate controller is connected to a field bus and the field bus is in turn connected to automation units, which represent a decentralized peripheral system. In general, the automation units are designed as input/output assemblies and can be directly connected to sensors and actuators in an automation installation on site at the machines. The decentralized input/output assemblies can be connected to a main module directly or to the main module by a submodule. In the latter configuration, a commissioner in the case of an automation installation of this type is faced with the problem of correspondingly mapping the input/output addresses of the decentralized peripheral system to address ranges in the main module. For this purpose, in accordance with conventional practices, in an application program of the submodule, for example, where the application program is designed as a cyclically executed programmable logic controller (PLC) program, the assignment is performed using a copy mechanism.

In addition, functional components, such as DB-send and DB-receive are available in the application program. The peripheral data of the input/output units are read in from the submodule and stored in a data component, where an assignment to an address range in the main module occurs and the address ranges thus assigned or the data contents thereof are transmitted to the main module under a transmission command. The application program copies the input/output data of the decentralized peripheral system and makes them available over a data interface to the superordinate main module. As a result, the superordinate main module is additionally burdened with computational complexity. This additional burden is associated with an execution time of the application program in the processing cycle of a programmable logic controller.

The run time of this application cycle has the critical responsibility of ensuring that the input/output data is up-to-date. For an installation operator with an industrial automation installation equipped with automation devices that forward decentralized peripheral data to a superordinate main module, it is important on account of an optimized control process to obtain the peripheral data at the “correct” point in time. Moreover, for the installation operator it is desirable for the application program not to be concerned with unnecessary copy tasks.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a method for exchanging data in which the burden on the application program is reduced. It is also an object of the invention to provide a submodule for the exchanging peripheral data with a main module that is configured to achieve a reduction of the burden on the application program.

These and other objects and advantages are achieved by creating a copy list that contains the peripheral transfer data record that is allocated a data range indication and a direction indication, where the copy list is then stored in the submodule and a transfer device is embedded into an operating system, and where the transfer device accesses the copy list and allocates the peripheral data to the corresponding address ranges based on the peripheral transfer data record. This solution achieves a displacement of a copy cycle into the operating system of a submodule, and hence independence of an application program executed in the submodule. An application cycle is no longer delayed by the copy tasks of peripheral data.

In an embodiment, a memory area derived from the peripheral transfer data record is made available in the submodule and, with the memory area, a data interface for transferring the peripheral data to the main module and for transferring the peripheral data from the main module to the memory area is provided. The data interface, which is defined by a memory area, can be regarded as a type of transfer area in the submodule. Peripheral data of the type input data, output data or mixed data comprising input/output data, of any desired data interface and a predeterminable length, can be stored in the transfer area. The data structure and the length then correspond to the data structure as that which prevails at the peripheral units. Here, the data interface is furthermore configured to detect possible peripheral access errors during copying. These peripheral access errors can then be detected, for example, by the useful data companions Input/Output Operations Per Second (IOPS) and Input/Output Control System (IOCS), where are customary in the case of a PROFINET IO protocol, and a superordinate controller or the main module thus obtains information about access problems of the subordinate peripheral system.

In a further embodiment, a priority list is added to the copy list, where the priority list is processed as a priority by the transfer device for time-critical data. At the peripheral units, for example, it is possible to send important data records and/or alarms to which it is necessary to react as rapidly as possible. If such an alarm is stored in the priority list, for example, then the transfer device is designed to process these time-critical alarms as a priority.

It is also advantageous if an application program executed in the submodule can access the exchanged peripheral data.

In a further optional method step, the copy list is created by of a configuration tool, where the configuration tool accesses configuration data with regard to a physical construction of the main module and submodules subordinate thereto, and the peripheral units are subdivided into peripheral units assigned centrally to the submodule and into peripheral units assigned to the submodule in a decentralized manner. Configuration tools are already available to configure a physical configuration of automation components in an installation interconnection. These configuration tools are advantageously developed in terms of method technology such that a corresponding configuration of the user can be projected into main modules and/or submodules with central or decentralized assemblies.

The object of the invention is also achieved by a submodule for the exchanging peripheral data with a main module. Here, the submodule comprises an operating system, an application program for implementing control tasks, and an interface configured to read in data from a peripheral unit and/or outputting data to the peripheral unit. The submodule is distinguished by having a transfer device embedded into the operating system, where the transfer device is configured to access a copy list and to perform a data exchange between the submodule and the main module. As a result, it is possible to achieve a reduction of the burden on the application program.

The following advantages are afforded for an installation operator and a project planner who has to design the corresponding installation with submodules of this type. For example, a user can configure a “transparent” peripheral system for data exchange with a main module in a simple manner. Performance of the application program is increased because the application program is no longer responsible for copy tasks or peripheral data. The up-to-date nature of the data is therefore likewise increased. By embedding the transfer device into the operating system, a copy cycle can be performed more rapidly than in the application program.

Preferably, the submodule is equipped with a data interface for transferring the peripheral data with a copy list to the main module and for transferring the peripheral data with the copy list from the main module to the submodule, where the copy list contains a peripheral transfer data record having a data range indication and a direction indication, and the transfer device is furthermore configured to provide the peripheral data in accordance with the copy list in the data interface. Here, the data interface is preferably configured as a predeterminable memory area in the submodule.

In a further embodiment, the submodule has an internal interface for connecting peripheral units that are assigned centrally to the submodule. Here, the submodule can be envisaged as an expandable decentralized peripheral unit with an integrated CPU. Depending on the application, additional assemblies for inputting and outputting data can be attached to this expandable peripheral unit.

In a further embodiment, the submodule has a second interface that is configured to connect peripheral units that are assigned to the submodule in a decentralized manner, where the second interface comprises a field bus interface.

Preferably, the submodule has a first interface for connecting the main module. In one embodiment, the first interface comprises an I/O interface for Profinet, i.e., for an industrial Ethernet, and the second interface comprises a Profibus DP interface.

The submodule expediently has a priority device which is configured to access a priority list to react to time-critical signals or alarms, and to correspondingly control the transfer device in accordance with a time-critical peripheral datum to be exchanged, where the transfer device is configured to react to a priority signal.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1is a schematic block diagram of an automation installation comprising a main module20and a submodule21. The main module20is connected by a main module interface20ato the submodule21through a first field bus11, and the submodule21has a first interface27for connection to the first field bus11. The submodule21is connected by a second interface28to a second field bus12. The second field bus12is in turn connected to a third peripheral unit24and a fourth peripheral unit25. Here, the peripheral units24,25comprise peripheral units arranged in a decentralized manner with respect to the submodule21. As a counterpart to the decentralized peripheral units24,25, the submodule21has a first peripheral unit22and a second peripheral unit23, as peripheral units arranged centrally with respect to the submodule21. For exchanging peripheral data between the main module20and the submodule21, when the peripheral units22,23are directly connected to the submodule21and the peripheral units24,25are connected in a manner remote from the submodule21over the second field bus12, peripheral transfer data records are defined, where these peripheral data records have a first address range of the respective peripheral units22,23,24,25and a second address range of the main module20. Peripheral transfer data records41,42,43(seeFIG. 3) map the peripheral data prevailing in the first address range into the second address range and/or map the peripheral data prevailing in the second address range into the first address range. A data interface26is provided in the submodule for this mapping.

FIG. 2schematically illustrates the submodule21depicted inFIG. 1. With reference toFIG. 2, the submodule21has an operating system30, an application program31, a data interface26, a copy list32, a priority device34and interfaces for communication with the outside world. The interfaces include an internal interface29, to which further peripheral assemblies can be attached directly to the submodule21, the first interface27, for connection to a superordinate level over a field bus (not shown), and the second bus interface28for connection to a subordinate level over a further field bus (not shown). The operating system30controls the internal sequences of the submodule21. Preferably, the submodule21is configured as an independent programmable logic controller (PLC). An application-dependent application program31is used for implementing tasks appertaining to control technology. A transfer device33is embedded into the operating system30, where transfer device33is configured to access the copy list32and to perform data exchange between the submodule21and the main module20(seeFIG. 1). As a result, it is possible to achieve a reduction of the burden on the application program31.

The peripheral data can be exchanged not only from the submodule21to the main module, but also from the main module20to the submodule21. The copy list32contains a plurality of peripheral transfer data records41,42,43(seeFIG. 3). The peripheral transfer data records41,42,43in turn have a data range indication41a,42a,43aand a direction indication41b,42b,43b. The transfer device33is furthermore configured to provide the peripheral data in accordance with the indications in the copy list32in the data interface. For example, the indication of a slot, a subslot and address type for an I/O controller is entered in the copy list. In the submodule21, an address type, a start address, a length and optionally a process image for input data are then designated by the copy list. For output data, a start address, a length and a process image are likewise stipulated in the copy list. A direction indication41bindicates where the input/output data are intended to be copied. For example, a direction indication from the submodule to the main module is a valid direction indication.

The copy list32is created by a configuration tool. Here, the configuration tool has recourse to physical construction data of the automation construction illustrated inFIG. 1. For the peripheral units22, . . . ,25it holds true that they can be arranged either centrally with respect to the submodule21or in a decentralized manner with respect to the submodule21. A user can then select, with the aid of the configuration tool, central or decentralized peripheral units, submodules, modules or group fields in the peripheral system. A corresponding transfer area for the interface26is made available by this selection performed based on programming. This interface is also known to the person skilled in the art as an input device (I-device) interface.

For project planning using the configuration tool, the following advantages are afforded for the installation user. For example, a user can configure a transparent peripheral system at the I-device interface in a simple manner. The performance of the peripheral transfer areas, i.e., the “freshness” of the data, is optimized and is independent of a copy cycle that would normally be performed in an application program with an application cycle.

FIG. 3shows a copy list32comprising three peripheral transfer data records41,42,43. A first peripheral transfer data record41has a first range indication41aand a first direction indication41b. A priority list44is available in the copy list32for the time-critical data exchange of, for example, alarms or particular data records.

FIG. 4is a flow chart of a method for exchanging peripheral data between a main module and a submodule a peripheral unit connected to the submodule, where data is read in or output through the peripheral unit. The method comprises defining a peripheral transfer data record having a first address range of the peripheral unit and a second address range of the main module, as indicated in step410.

At least one of a peripheral data prevailing in the first address range is mapped into the second address range and peripheral data prevailing in the second address range is mapped into the first address range, as indicated in step420.

A copy list having the peripheral transfer data record which is allocated a data range indication and a direction indication is created, as indicated in step430. The copy list is stored in the submodule, as indicate in step440. A transfer device is embedded into an operating system of the submodule, as indicated in step450. Here, the transfer device accesses the copy list and allocates the peripheral data to corresponding address ranges based on the peripheral transfer data record.