Abstract:
An automation device includes a master module, and a slave unit having a slave modules, where an IM module of the slave modules of the slave unit is connected to the master module via a bus, where each of the modules is parameterizable using a message transmitted to the IM module by the master module, the message includes a data area for each of the slave modules for parameterization of each of the slave modules, and the message includes a data area for each slave module for its parameterization, wherein at least one default parameter data record is stored in at least one of the slave modules, and wherein a data record index, which is stored in that data area of the message which is provided for the at least one slave module is provided for accessing the at least one default parameter data record.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to an automation device having a master module, and a slave unit having a plurality of slave modules, where an IM module of the plurality of slave modules of the slave unit is connected to the master module via a bus, where each of the plurality of slave modules is parameterizable using a message transmitted to the IM module by the master module, and where the message includes a data area for each of the plurality of slave modules for parameterization of each of the plurality of slave modules. 
         [0003]    2. Description of the Related Art 
         [0004]    An automation device is known from the Siemens catalog ST PCS 7, June 2012 edition, chapter 8. So-called “decentralized peripherals” are provided for tackling automation tasks in a decentralized manner in the field of production, process and method technology and usually comprise different slave units or peripherals that are provided with a plurality of slave modules and are each connected to a master module via an IM module of the slave units and via a PROFIBUS DP. In this case, the master module is usually part of a powerful programmable logic controller that is provided with at least one CPU module and further functional modules and is intended to tackle more complex automation tasks, where the CPU module itself is able to be designed to undertake the tasks of the master module. 
         [0005]    Actuators and/or sensors can be connected to these slave modules of a slave unit, where process peripheral input data transmitted from the sensors can be stored in the slave modules, and process peripheral output data that are transmitted to the slave modules by the master unit can be supplied to the actuators by the slave modules. 
         [0006]    So that a slave unit formed with a plurality of slave modules can be used to tackle automation tasks, the slave modules must be parameterized. For this purpose, the master module transmits a message having a message identifier (i.e., a data record number), which indicates that the message is a parameter message, to the IM module of the slave units via the bus. In addition to this message identifier, the message has data areas comprising the address of the slave unit to be addressed, the slot addresses or the slot numbers of the slave modules in the slave unit and parameters for parameterizing the slave modules. The size of these data areas of all slave modules usually must not exceed 244 bytes, which means that the number of slave modules which can be operated or used in a slave unit is restricted. For example, the situation may occur in which a data area of 50 bytes is respectively required for a first slave module and a second slave module of one manufacturer or supplier and a data area of 150 bytes is required for a slave module of another manufacturer on account of the multiplicity of parameters which can be set. This means that these three slave modules cannot be used together in a slave unit because the message length with respect to the data area of 244 bytes cannot be exceeded. 
       SUMMARY OF THE INVENTION 
       [0007]    It is therefore an object of the invention to provide an automation device that can be used to increase the number of slave modules that can be used in a slave unit. 
         [0008]    This and other objects and advantages are achieved by storing at least one default parameter data record in at least one of the slave modules, and by storing a data record index in the message in the data area provided for the at least one slave module, for accessing the at least one default parameter data record. 
         [0009]    It is advantageous that the size of the data area of the message transmitted from the master module to the slave unit is considerably reduced and that the slave modules can be parameterized in a faster manner, in particular when starting up the automation device. 
         [0010]    If the master module transmits a message to the slave unit, then the interface module of this slave unit identifies from the data record number that the message is a parameter message and also identifies, from the slot addresses or slot numbers, which slave modules need to be accessed with regard to their parameterization. By means of the data record index stored in the data area of the message, the slave module accesses the default data record stored in this slave module for its parameterization. Depending on the range of functions or expansion level of a slave module, this slave module may have a plurality of default data records, where a data record index is respectively provided for each of these default data records. 
         [0011]    In accordance with the invention, the large memory of the slave module(s), which is present anyway, is used to largely avoid the interfering effects of the small size of the parameter data area in the message. 
         [0012]    In one embodiment of the invention, envisaged or intended changes of parameters in the at least one default parameter data record are likewise stored in that data area of the message which is provided for the at least one slave module. If a default parameter, such as the baud rate, is not intended to be accepted in the default parameter data record and is intended to be replaced with a new value, this is indicated in the data area in the message via a byte or bit identifier, which corresponds to the byte or bit in the default parameter data record, and the new baud rate. The baud rate originally stored in this byte or bit in the default parameter data record is replaced with the new baud rate with respect to the parameterization of the slave module. Based on such measures, changes can be easily made to the at least one default parameter data record and no further default parameter data records need to be created for a multiplicity of parameter configurations. 
         [0013]    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 
         [0014]    The invention, its refinements and advantages are explained in more detail below using the drawing which illustrates an exemplary embodiment of the invention and in which, in which: 
           [0015]      FIGS. 1 and 3  show a slave module; and 
           [0016]      FIGS. 2 ,  4  and  5  show an automation device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    The same parts illustrated in  FIGS. 1 to 5  are provided with the same reference symbols. 
         [0018]    With initial reference to  FIG. 5 , which illustrates a conventional automation device  1 , parts of this automation device  1  for controlling a technical process are a programmable logic controller  2  having a CPU module  3 , a master module  4  and three slave units  5 ,  6 ,  7 . The slave units  5 ,  6 ,  7  each have an interface module  5   a,    6   a,    7   a  which is used by the master module  4  to have read and/or write access to the slave modules of the slave units  5 ,  6 ,  7 . It should be understood that the programmable logic controller  2  has further modules, such as a plurality of analog and/or digital input/output modules, communication modules and other modules suitable for operating the programmable logic controller  2  and for controlling the process. In addition, it should be understood that the CPU module  3  itself may be designed to undertake the tasks of the master module  4 . 
         [0019]    In the present exemplary embodiment, only slave modules  5   b,    5   c,    5   d  of the slave unit  5  are illustrated for the sake of clarity. In order to parameterize these modules, the master module  4  transmits a parameter message Pr 1  to the interface module  5   a  of this slave unit  5  via a bus  8 , such as a PROFIBUS DP. This message Pr 1  comprises a data record number that indicates to the slave units  5 ,  6 ,  7  that the message Pr 1  is a parameter message. The message Pr 1  also comprises an address for addressing the slave unit  5  and data areas Bb, Bc, Bd assigned to the slave modules  5   b,    5   c,    5   d.  These data areas Bb, Bc, Bd are each provided with a slot number or slot address for addressing the respective slave module  5   b,    5   c,    5   d  and also have parameters for parameterizing the respective slave module  5   b,    5   c,    5   d.  In the example shown, the size of the data areas Bb, Bc in the message Pr 1  is 8 bytes in each case and, in contrast, the size of the data area Bd is 150 bytes, which indicates that, for the slave module  5   d,  considerably more parameters are needed to parameterize this slave module  5   d  in comparison with the slave modules  5   b,    5   c.    
         [0020]    On account of the fact that only 79 bytes (area Bx 1 ) of the maximum length of 244 bytes can be occupied in the message Pr 1 , a further slave module can be plugged into a free slot  9  of the slave unit  5  only if the data (i.e., slot address, parameters) for this slave module do not exceed these 79 bytes. 
         [0021]    In order to make it possible for a further slave module, for which more than 79 bytes of data are required, to also be able to be inserted into the free slot  9  in the slave unit  5  in this case, slave modules are provided and are configured such that a default parameter data record is stored in a memory of such slave modules and can be accessed using a data record index. This index is stored in that data area of the message which is provided for this slave module, which message is transmitted by the master module to the interface module of the respective slave unit. Such slave modules, for which a multiplicity of parameters are needed for their parameterization, are preferably configured as described. 
         [0022]      FIG. 1  shows such a slave module  5   e  having a memory  10  that stores a default parameter data record  11  having parameters, this data record having a size or length of 150 bytes. Based on a data record index  13  supplied to a controller  12  of the slave module  5   e,  the default parameter data record  11  is loaded into a parameter memory  14  of the controller  12 , as a result of which the slave module  5   e  is parameterized. As described, the data record index is part of a parameter message which is transmitted by the master module to a slave unit. 
         [0023]    For the purpose of a more detailed explanation, reference is made to  FIG. 2  which, for greater clarity, illustrates the automation device  1  described in  FIG. 5  without the slave units  6 ,  7 . Instead of being equipped with the slave module  5   d  (see  FIG. 5 ), the slave unit  5  is equipped with the slave module  5   e,  where the master module  4  supplies a parameter message Pr 2  to the slave unit  5  to parameterize the slave modules  5   b,    5   c,    5   e.  In contrast to the parameter message Pr 1  (see  FIG. 5 ), this parameter message Pr 2  has, instead of the data area Bd, a data area Be with a length of 2 bytes, in which only the data record index  13  and a slot number  15  or slot address are stored. In the present exemplary embodiment, the numbers “2, 3, 4” are allocated to the slave modules  5   b,    5   c,    5   e  as slot numbers  15 . As described, the interface module  5   a  uses this slot number  15  to address the slave module  5   e,  and the data record index  13  is used to indicate to the slave module  5   e  that the default parameter data record  11  comprising 150 bytes should be transmitted from the memory  10  to the parameter memory  14 . As a result of the fact that the size of the area Be is only 2 bytes, 227 bytes can be used as a free area Bx 2  in the message Pr 2  for the purpose of parameterizing further slave modules. 
         [0024]    It should be understood that the slave modules  5   b,    5   c  can be configured in a manner corresponding to the slave module  5   e,  only 2 bytes—1 byte for a slot number and 1 byte for a data record index—likewise being required in this case for the areas Bb, Bc in the message, and the slave modules  5   b,    5   c  each also having a default parameter data record having a length or size of 8 bytes. 
         [0025]    The situation may occur in which a slave module can be configured in various ways depending on the operating mode and functionality. In order to be able to set different configurations using the parameters, the slave module in this case has a plurality of default parameter data records which are again referenced using a data record index. In the present exemplary embodiment, five default parameter data records D 1  to D 5  of the same data structure or the same format are provided for a slave module  5   f  (see  FIG. 3 ) and are stored in a memory  16  of the slave module  5   f.  Each of these default parameter data records D 1  to D 5  each comprising 150 bytes is again accessed using the data record index  13 . The data record index  13 , for example an index “3”, causes the controller  12  to enter the default parameter data record D 3  in the parameter memory  14 . 
         [0026]    The situation may also occur in which some parameters stored in a default parameter data record must frequently be changed, but the intention is to dispense with storing a multiplicity of default parameter data records for the different parameter configurations or settings in a slave module. In order to restrict the number of default parameter data records stored in this slave module, provision is therefore made for parameters which need to be frequently changed to be able to be accessed in a default parameter data record and to be easily changed. 
         [0027]    It is assumed below that parameters that need to be frequently changed are stored in bytes  1  to  9  in the default parameter data record D 3  (see  FIG. 3 ). These 9 bytes are accessed by reserving a further 9 bytes  1  to  9 , in which the new parameters are stored (see  FIG. 4 ), in an area Bf assigned to the slave module  5   f  in a parameter message Pr 3 . Here, the interface module  5   a  uses the slot number  15  to address the slave module  5   f  and uses the data record index  13  to address the default parameter data record D 3 , based on which this default parameter data record D 3  is loaded into the parameter memory  14 , in which case, on account of the new parameters stored in bytes  1  to  9 , the parameters loaded into the parameter memory  14  are overwritten in the bytes which correspond or are assigned to these bytes  1  to  9 , which is indicated in  FIG. 3  via a reference symbol  17 . As described, such measures reduce the number of default parameter data records to be stored in the memory  16  of the slave module  5   f,  but also reduce a free area Bx 3  in the parameter message Pr 3  because additional bytes  1  to  9  need to be reserved or specified in said message to make changes in the referenced default parameter data record D 3 .] 
         [0028]    Thus, while there have 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 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.