Abstract:
There is described a backplane with connections for connecting functional units. The backplane has hardware resources to handle software tasks, wherein the hardware resources are redundantly implemented or comprise essentially identical hardware modules, and wherein the hardware resources are organized in such that the software tasks are dynamically assigned to the hardware resources.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is the US National Stage of International Application No. PCT/RU2005/000653, filed Dec. 20, 2005 and claims the benefit thereof. The International Application is incorporated by reference herein in its entirety. 
     
    
     FIELD OF INVENTION 
       [0002]    The invention relates to a backplane with connections for connecting functional units. 
       BACKGROUND OF INVENTION 
       [0003]    A backplane of this kind is known from Siemens Catalog ST 70, pages 5/93 to 5/96, 2005 edition. The backplane is intended for a programmable controller and has slots into which functional units, e.g. functional units in the form of a CPU board, communication board, input/output board or other board or module suitable for the programmable controller, can be inserted. The programmable controller is designed for controlling a technical process and for solving control and automation tasks in the lower, medium and upper performance class. Which functional units and how many of these functional units are to be used is dependent on the automation task to be solved, functional units being used on a redundant basis as required. Should the programmable controller have to be extended in order e.g. to solve a more complex automation task, it is generally necessary to equip the programmable controller with new CPU and/or other intelligent functional module, to replace already inserted modules by more powerful ones and/or to provide the programmable controller with additional software functional modules. This procedure is expensive and prone to error. In addition, it is necessary for a large number of functional units to be held in store. 
       SUMMARY OF INVENTION 
       [0004]    An object of the present invention is to specify a backplane of the abovementioned type which allows adaptation to an automation task to be solved. 
         [0005]    This object is achieved by the measures set forth in an independent claim. 
         [0006]    By means of the invention, adaptation to an automation task to be solved is essentially effected by the backplane provided with the hardware resources and by the software tasks fed to the backplane. 
         [0007]    By means of essentially identical hardware components, the possibility of distributing the software task to them is created. The invention is based on the idea of implementing present-day functional modules, e.g. functional modules in the form of CPU boards, in future in software and expanding the present-day backplane with appropriate hardware (essentially identical hardware components). 
         [0008]    The advantage of this is that it obviates the need to use CPU or other intelligent functional boards to solve an automation task. The functionality and action of these modules is essentially realized by uniform hardware resources of the backplane and by at least one software task which a remote location communicates to the backplane. The hardware resources are organized in such a way that the software task can be dynamically assigned to them, the hardware resources themselves or a configuration controller effecting the assignment and the hardware resources handling the software task. By means of the essentially uniform hardware resources and the possibility of remote configuring via the remote location, dynamic adaptation of the backplane&#39;s resources e.g. to a more complex system to be controlled is facilitated. 
         [0009]    At runtime of a software task or of a plurality of software tasks, additional software tasks can be fed to the backplane which are assigned to the hardware resources together with the already fed software tasks, load sharing of the hardware resources being possible at runtime of the software tasks. This on the one hand further improves the flexible matching of software tasks to the backplane&#39;s resources and, on the other, achieves essentially homogeneous load distribution. 
         [0010]    The hardware resources exchange information via a high-speed bus, each hardware resource essentially having a microprocessor, a memory and an input/output processor. The component parts of each hardware resource are preferably realized in the form of a “system-on-programmable-chip” which itself dynamically varies or adapts the structure of its components as a function of the division or breakdown of a control task. 
         [0011]    In one embodiment of the invention it is provided that a “hot stand-by resource” can be assigned to at least one of the hardware resources, thereby enabling a redundant operating mode of hardware resources for solving automation tasks with exacting requirements in terms of failure safety to be realized. 
         [0012]    In another embodiment of the invention the backplane is provided with an evaluating processor unit for monitoring the hardware resources. In the event of a hardware resource fault, the evaluating processor unit switches this hardware resource to passive mode. In this case the software tasks are assigned to the remaining fault-free hardware resources, thereby maintaining automation operation. 
         [0013]    Advantageously the hardware resources are implemented in the form of “flat electronic panels” which are connected to the backplane using “flat cut-off connectors”, thereby enabling a faulty hardware resource to be easily removed from the backplane and replaced by a new hardware resource. 
         [0014]    The backplane can be provided with a communication controller for communicating with the remote location and with a configuration controller in which the configuration of the hardware resources activated and/or to be activated is stored. The configuration controller enables hardware resources to be activated, deactivated, reassigned and/or tested. 
         [0015]    Further advantageous embodiments of the invention will emerge from the other sub-claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The invention, its embodiments and advantages will now be explained in greater detail with reference to the accompanying drawings which illustrate an exemplary embodiment and in which 
           [0017]      FIGS. 1 and 2  show simplified diagrams of an arrangement using a reconfigurable backplane. 
       
    
    
       [0018]    The same reference characters are used to denote the same parts illustrated in  FIGS. 1 and 2 . 
       DETAILED DESCRIPTION OF INVENTION 
       [0019]    In  FIG. 1 ,  1   a  denotes a reconfigurable backplane  1   a  which is provided with a communication controller  2 . Via this communication controller  2  and a communication network  3 , the backplane  1   a  is connected to a remote location  4  by which software tasks can be fed to the backplane  1   a . The remote location  4  can be implemented e.g. in the form of a personal computer, known per se, which is provided with a suitable Internet browser. In this case communication between the remote location  4  and the backplane  1   a  can take place via the Internet or World Wide Web. Other essential component parts of the backplane  1   a  are redundantly implemented hardware resources  5   a ,  5   b ,  5   c ,  5   d ,  5   e , a configuration controller  6  and slots  7 . In the example shown the hardware resources  5   a ,  5   b ,  5   c ,  5   d ,  5   e  are activated and provided for handling software tasks  8 . On the other hand the hardware resources  5   f ,  5   g  and  5   h  are deactivated and serve as spare hardware resources in order e.g. to facilitate dynamic adaptation of the resources to a more complex automation task to be solved. 
         [0020]    Via a high-speed bus  9 ,  10 , the hardware resources  5   a , . . .  5   h  exchange information bits which can access the slots  7  in read and/or write mode via another bus  11 . Insertable in these slots  7  are e.g. input/output devices  12  to which sensors and/or actuators  13  are connected which are provided for detecting process input signals of a system to be controlled or for outputting process output signals. Each hardware resource  5   a , . . .  5   h  is provided with a microprocessor  14 , an input/output processor  15  and a memory  16 , each hardware resource  5   a , . . .  5   h  being able to access both its own memory  16  and the memory  16  of the other hardware resources  5   a , . . .  5   h  in read and/or write mode. 
         [0021]    It will now be assumed that the software tasks  8  include a first and a second PLC (programmable logic controller) task  8   a ,  8   b , a web server task  8   c  and a manager task  8   d . The first and second PLC tasks  8   a ,  8   b  are provided to implement a programmable control in each case which simulates the functionality of a CPU module processing a control program. The web server task  8   c  is used e.g. for providing information according to the so-called HTTP protocol and the manager task  8   d  administers, for example, the deactivated spare hardware resources  5   f ,  5   g ,  5   h . The hardware resources  5   a ,  5   b , . . .  5   e  are organized in such a way that the PLC tasks  8   a ,  8   b , web server task  8   c  and manager task  8   d  fed to the backplane  1   a  by the remote location  4  can be dynamically assigned to these hardware resources  5   a ,  5   b , . . .  5   e . In this example the configuration controller  6  assigns these tasks  8   a , . . .  8   d  to the hardware resources  5   a ,  5   b , . . .  5   e  for handling the tasks  8   a , . . .  8   d , preferably in such a way that an essentially homogeneous load sharing of hardware resources  5   a ,  5   b , . . .  5   e  is effected. 
         [0022]    The configuration controller  6  can be dispensed with if the hardware resources assign the software tasks  8  to themselves. For further explanation, reference will now be made to  FIG. 2 . 
         [0023]    In contrast to the backplane  1   a , a backplane  1   b  has a plurality of hardware resources, each of which is implemented in the form of a hardware module  17 . These have connecting means (not shown here) via which the hardware modules  17  can be mechanically and electrically combined. Essential component parts of the hardware resources of each module  17  are a microprocessor  18 , a memory  19  and an input/output socket  20 , assembled hardware modules  17  being interconnected via a bus  21 ,  22 . A backplane  1   b  of this kind can be easily expanded with other hardware modules  17 , whereby in the case of expansion with other hardware modules  17  the hardware resources themselves re-assign and handle the software tasks  8 . To the input/output sockets  20  there can be connected, e.g. via a suitable communications link  23 , input/output devices  24 , e.g. in the form of intelligent field devices, which are connected to other automation components  24 . The software tasks  8  are transmitted by the remote location  4  to the backplane  1   b  via the communication network  3 , information being exchangeable between the backplane  1   b  and the remote location  4  either via one of the input/output sockets  20  and an Ethernet adapter  25  or via an Ethernet socket  26  of a terminating module  27  of the backplane  1   b.