Abstract:
An automation device has a main module and an interchangeable connection module in which a fieldbus port of the automation device is located. The automation device is characterized in that the interchangeable connection module contains a non-volatile memory which can be read out by the main module of the automation device. A method for operating the automation device includes the steps of connecting a main module of the automation device with a connection module, reading the non-volatile memory of the connection module, detecting any incompatibilities between the main module and the connection module, and placing the automation device in operation if no incompatibilities are detected.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to an automation device having a main module and an interchangeable connection module including a fieldbus port for the automation device. The invention further relates to an interchangeable connection module for an automation device of this type, and to a method for operating an automation device having an interchangeable connection module. 
         [0002]    In industrial automation systems, at least one control computers, master computer, or programmable logic controller (PLC) and a plurality of field devices are provided. Fieldbuses are used to transmit control data and/or measured values between the computers or controllers and the field devices. The field devices include input and output modules, hereinafter abbreviated to I/O (input/output) modules, which provide analog and/or digital input and/or output channels through which system components can be controlled and through which measured values, for example from sensors, can be read or input. Frequently, rather than being connected directly to a fieldbus, each field device is connected to a fieldbus via a fieldbus coupler which acts as a data interface between the fieldbus on one side and an often proprietary sub-bus on the other. A plurality of bus-capable modules, for example the I/O modules, can be coupled to the sub-bus. 
         [0003]    As described herein, an automation device is construed to be any component of an automation system that has a fieldbus port. Thus, automation devices include both control computers and fieldbus couplers or field devices that are connected directly to a fieldbus. 
       BRIEF DESCRIPTION OF THE PRIOR ART 
       [0004]    A number of different fieldbus systems are in standard use in automation systems. These include, for example, Profibus, Profinet and EtherCAD. To avoid having to provide automation devices in a plurality of different configurations for the various fieldbus systems, automation devices that have interchangeable connection modules for the different fieldbus systems are known, as disclosed for example in German patent No. DE 10 2004 056 363 A1. The modular connection concept decreases the costs of developing, producing and storing the automation devices. For users of the automation devices, the modular system also facilitates changing the fieldbus system in an existing system or reusing automation devices in new systems, even when a fieldbus system is different from those previously used. 
         [0005]    With a modular system of this type, however, there is a risk that an automation device might be operated using an unsuitable connection module. Certain pairings of an automation device and a connection module may not be allowable owing to hardware engineering, software engineering and/or licensing reasons. 
         [0006]    The present invention was developed in order to overcome these and other drawbacks of the prior devices by providing an automation device and a connection module that is suitable for use in the automation device in which compatibility problems between the main module and the connection module are prevented, as well as a method for operating such an automation device. 
       SUMMARY OF THE INVENTION 
       [0007]    An automation device according to the invention includes a connection module having a non-volatile memory that can be read out by the main module of the automation device. 
         [0008]    Information regarding the compatibility of the various devices can be stored in the non-volatile memory of the connection module. In this manner, once the automation device has been coupled to the connection module, the automation device can query whether the connection module is suitable and permissible in terms of hardware, software or licensing factors for cooperating with the main module of the automation device. Furthermore, the non-volatile memory of the connection module may contain programs or program elements or program sections which can be read in by the automation device once it has been coupled to the connection module, and any preexisting software-related incompatibilities can be rectified. 
         [0009]    In a preferred embodiment of the automation device, the non-volatile memory of the connection module is a flash memory, a ferroelectric memory (FRAM—Ferroelectric Random Access Memory) or an EEPROM (Electrically Erasable Programmable Read-Only Memory). The non-volatile memory is preferably permanently soldered to a circuit board of the connection module, with components of an interface driver and/or of a central control unit for operating the fieldbus port of the connection module being arranged on the circuit board. Integrating the non-volatile memory into the circuit board of the fieldbus port makes tampering with the connection module more difficult. 
         [0010]    In a further preferred embodiment, the non-volatile memory is connected with a control unit or with an interface driver for the fieldbus port of the connection module. This allows the non-volatile memory to also be used for receiving information to be stored for the connection module, for example firmware for the connection module. 
         [0011]    In a further embodiment of the automation device, the connection module has a plug connector for connecting with the main module of the automation device, the plug connector being coupled to the non-volatile memory in the connection module. The coupling between the plug connector and the non-volatile memory can then be established directly via an interface driver assigned to the non-volatile memory. In that case, the plug connector provides a separate data channel for transmitting the data from the non-volatile memory to the main module. A plug connector used solely for the data channel may be provided, or part of a plug connector that is also used for other purposes may be used for the data channel 
         [0012]    Alternatively, the non-volatile memory can be connected via an interface driver to a central control unit of the connection module and can be coupled via the control unit and optionally via an additional interface driver to the plug connector. In that case, only one data channel is established between the main module and the connection module through which the data from the non-volatile memory are transmitted to the main module and the fieldbus data are exchanged. 
         [0013]    In a further embodiment of the automation device, the main module and/or the connection module have couplers for mechanically connecting the connection module to the main module. The couplers are preferably in the form of locking hooks. 
         [0014]    According to another embodiment of the automation device, the main module and/or the connection module are designed to be mounted on a mounting rail and in particular contain a recess for snap-on connection with the mounting rail. In addition to the mechanical interconnection of the main module and the connection module, this allows the automation device to be mechanically secured in an equipment cabinet for example. 
         [0015]    In other embodiments of the automation device, the device is a fieldbus coupler and/or a control computer. 
         [0016]    The invention is also directed to a connection module for an automation device, the connection module containing a non-volatile memory which can be read out by a main module of the automation device via a plug connector located on the connection module. 
         [0017]    The invention also encompasses a method for operating an automation device in which a main module of the automation device is connected to a connection module, and a non-volatile memory of the connection module is read out by the main module. Any incompatibilities that exist between the main module and the connection module are then detected. If no incompatibilities are detected, the automation device is placed in operation. 
         [0018]    In one embodiment of the method, data from the non-volatile memory of the connection module are used in the main module to rectify any incompatibilities that may exist. In a further embodiment, data from the non-volatile memory of the connection module are used to update operational software, particularly firmware, in the main module. 
         [0019]    According to another embodiment of the method, the connection module provides a wireless communication channel. The wireless communication channel can be used to link a laptop computer or tablet to the main module via the connection module for diagnostic or configuration purposes. The connection module thus further expands the main module as needed with this connection option. As a result, the modularity of the system and its capacity for upgrading are further increased. The wireless communication channel can be based on a WLAN (Wireless Local Area Network) standard, an NFC (Near Field Communication) standard, a Zigbee standard or a Bluetooth standard. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0020]    Other objects and advantages of the invention will become apparent from a study of the following specification when viewed in the light of the accompanying drawing, in which: 
           [0021]      FIGS. 1 a  and 1 b    are perspective views of a first embodiment of an automation device according to the invention showing a main module and a connection module in attached and detached conditions, respectively; 
           [0022]      FIG. 2  is an exploded side view of the detached main module and connection module of the automation device shown in  FIG. 1   b;    
           [0023]      FIGS. 3 a - c    are plan views of three types of connection modules of an automation device; 
           [0024]      FIG. 3 d    is a plan view of a main module for the connection modules of  FIGS. 3 a   - c;    
           [0025]      FIGS. 4 a - c    are plan views of different combinations of main and connection module according to the invention; 
           [0026]      FIG. 5  is a block diagram of an automation device; 
           [0027]      FIGS. 6 a  and 6 b    are perspective views of an alternate embodiment of an automation device according to the invention showing two main modules and a connection module in attached and detached conditions, respectively; 
           [0028]      FIG. 7  is an exploded side view of the detached main modules and connection module of the automation device shown in  FIG. 6 b   ; and 
           [0029]      FIG. 8  is a plan view of the automation device of  FIG. 6   a.    
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIGS. 1 a , 1 b    and  2  illustrate a first embodiment of an automation device according to the invention, in perspective view ( FIGS. 1 a  and 1 b   ) and in a side view ( FIG. 2 ). The automation device of this embodiment is a fieldbus coupler. 
         [0031]    The fieldbus coupler includes a fieldbus coupler main module  20 , hereinafter referred to as main module  20 , and a connection module  10  attached thereto.  FIG. 1 a    shows the fieldbus coupler in the assembled state, whereas  FIGS. 1 b    and  2  show connection module  10  detached from the main module  20 . 
         [0032]    The main module  20  includes a housing upper section  21 , the top surface of which includes a display and a connecting element  22 . The housing upper section  21  is attached to a housing lower section  23  which in the embodiment shown is designed to be mounted on a mounting rail, in particular a snap-on mounting rail, not shown. 
         [0033]    In this embodiment, connection module  10  includes a housing formed of multiple sections which in this case are an upper section  11  and a lower section  13 . On a top surface of connection module  10 , fieldbus ports  12  are provided. In the illustrated embodiment, two fieldbus ports  12  for receiving “RJ-45”-model plugs are shown. The connection module  10  is suitable for an EtherCAD fieldbus. 
         [0034]    In the housing lower section  13  of the connection module  10 , a mounting rail recess is provided, preferably a snap-on mounting rail recess  14 . T snap-on mounting rail recess  14  has a laterally acting locking slide for locking onto a snap-on mounting rail. To release the connection to the snap-on mounting rail, a lateral unlocking lever  15  is provided. 
         [0035]    As shown in  FIG. 1 a   , connection module  10  can be placed flush onto main module  20 , where it is mechanically coupled and preferably locked thereto. For this purpose, a coupler  24  is provided on the main module  20 . In this case, the coupler is in the form of a locking hook or hooks, which are shown in  FIGS. 1 b    and  2 . Couplers  24  engage in correspondingly undercut locking elements of connection module  10 . 
         [0036]    To establish an electrical connection between connection module  10  and main module  20 , a plug connector  16  is located on the connection module  10  and a complementary mating connector  26  is located on the main module  20 . When the main module  20  and the connection module  10  are coupled with one another, signals for actuating fieldbus ports  12  are transmitted between the two modules via the plug connector  16  and the mating connector  26 . Furthermore, a non-volatile memory integrated within the connection module  10  is connected via plug connector  16  and mating connector  26  to control devices of the main module  20  such that the main module  20  is able to access the contents of the non-volatile memory in connection module  10 . This will be described in greater detail below in connection with the schematic block diagram of  FIG. 5 . 
         [0037]      FIG. 3 d    shows the main module  20  and the connection module  10  of  FIGS. 1 and 2 , again in a plan view in which they are detached from one another. In this case, the connection module is identified by reference sign  10   a  in  FIG. 3   c.    
         [0038]    References  10   b  and  10   c  identify two additional embodiments of a connection module  10  for use with main module  20  of the fieldbus coupler as shown in  FIGS. 3 b  and 3 a   , respectively. These are distinguished from the connection module  10   a  by the use of a fieldbus port  12  of a different fieldbus system. Connection module  10   b  is suitable for a Profibus fieldbus. Connection modules  10   b  and  10   c  are further distinguished from connection module  10   a  in that adjustment elements  17  are provided which can be used for address coding for fieldbus port  12 . Of course, the adjustment elements  17  need not be located on the top surface of the connection modules  10   b,    10   c.  They may instead be located on a lateral surface. For adjustment elements in which inadvertent displacement is to be avoided wherever possible, arranging the elements on the side that faces the main module  20  is advantageous. It should be noted that, in addition to the adjustment elements  17  shown, display elements such as light-emitting diodes may be provided on the connection module  10 . 
         [0039]    In the plan view of  FIG. 3 d   , an unlocking lever  25  is also visible on the main module  20  and is used to release the snap-on mounting rail recess, not shown, provided on the main module  20 . On the side opposite the connection module  10 , the main module  20  has additional couplers  24 ′, which are identical in design to couplers  24 . These additional couplers  24 ′ are used for mechanical coupling to bus-capable modules, for example IO modules, which are connected with the fieldbus coupler main module  20 . 
         [0040]    For the electrical connection of modules of this type, bus contacts  27  are formed on the main module  20  which are used for current distribution, for the supply of power and for the exchange of data between the bus-capable modules and fieldbus coupler  20 . A similar mechanical configuration of the couplers between the bus-capable modules and the main module  20  of the fieldbus coupler and between the main module  20  and the connection module  10  enables housing components to be reused. For example, housing lower section  13  of the connection module  10  is substantially identical to at least part of the housing lower section  23  of the main module  20 . Housing lower section  13  of connection module  10  can also be used with the bus-capable modules. 
         [0041]      FIG. 4 a    shows a plan view of the fieldbus coupler including a main module  20  and a connection module  10   a.    FIGS. 4 b  and 4 c    show configurations of the fieldbus coupler in which a plurality of connection modules  10  are used simultaneously. 
         [0042]    For instance,  FIG. 4 b    shows a plan view similar to that of  FIG. 4 a    in which a connection module  10   b  is connected as an additional connection module to the combination of the main module  20  and connection module  10   a.  For this purpose, connection module  10   a  in this embodiment is configured such that it also has couplers, which are similar to couplers  24  of main module  20  and which can be used to establish the mechanical connection to the connection module  10   b.  Furthermore, on the side of the connection module  10   a  that faces connection module  10   b,  mating connectors similar to mating connectors  26  of the coupling module  20  are provided which can be used to establish an electrical connection between the two connection modules  10   a  and  10   b.    
         [0043]    Data exchanged between the main module  20  and the connection module  10   b  are forwarded by the connection module  10   a  via the combination of a mating connector  26  and a plug connector  16  or via the combination of the mating connector and the plug connector  16  of the connection module  10   b.  In this manner, data can be exchanged both between main module  20  and the connection module  10   a  and between main module  20  and the connection module  10   b.    
         [0044]    In the same manner as in  FIG. 4 b   ,  FIG. 4 c    shows a configuration in which the main module  20  of the fieldbus coupler is connected to a first connection module  10   a,  to which a second connection module  10   c  is connected. 
         [0045]      FIG. 5  is a block diagram showing the combination of a main module  20  and a connection module  10  of an automation device configured for an intended use. This may be the main module  20  and one of connection modules  10  or  10   a  to  10   c,  according to  FIGS. 1 to 4  for example. 
         [0046]    The main module  20  includes a central control unit  200  such as a microcontroller. The microcontroller is connected with interface drivers  201 ,  202  and  204  through which the control unit  200  is connected to various ports. Interface drivers  201  and  202  contact mating connectors  26  through which the electrical connection to the connection module  10  is established. Interface driver  204  couples control unit  200  to bus port  27 , to which the bus-capable modules (IO modules) are connected. The control unit  200  is also connected with a memory  203 . This memory can have volatile and/or non-volatile memory areas. An interface driver that may be required for controlling memory  203  is not shown. 
         [0047]    In the embodiment shown, the connection module  10  likewise includes a central control unit  100  such as a microcontroller. Connected to control unit  100  is a fieldbus interface driver  101  to which a fieldbus port  12  is coupled. Information is exchanged between the connection module  10  and the main module  20  between interface drivers  101  and  201 , such as with the interconnection of control unit  100 . A proprietary protocol may be used for this purpose, which does not correspond to the protocol of fieldbus port  12 . It also is not required that the hardware for the transmission of data via plug connector  16  and/or mating connector  26  correspond to that of fieldbus port  12 . The protocol will be converted in control unit  100  or in fieldbus interface driver  101 . However, it is also possible for the transmission of information between interface drivers  101  and  201  to be based on the same protocol and/or the same hardware specifications that are used for the fieldbus port  12 . 
         [0048]    According to the invention, the connection module  10  includes a non-volatile memory  103 , for example a flash memory, a ferroelectric memory (FRAM—Ferroelectric Random Access Memory) or an EEPROM (Electrically Erasable Programmable Read-Only Memory). The information in the memory is read out by the control unit  200  of the main module  20  via an interface driver  201  and the combination of the plug connector  16  and the mating connector  26 , and via an interface driver  202 . In the embodiment shown, the data transmission path used for this information is separate from the transmission path used for the data that are output at fieldbus port  12 . Accordingly, signal lines for the plug connector  16  and/or the mating connector  26  can be provided separately for the different data paths. In the embodiment of  FIG. 3 , this is also indicated by a spatial separation of the different regions of plug connector  16 . However, in the embodiment shown, a common plug housing is used. In alternative embodiments, when a common plug housing is used, spatial separation of the different regions of the plug is not required, particularly if the signal levels present in the different regions are of a comparable magnitude. 
         [0049]    In a method according to the invention, the automation device uses the main module to access the non-volatile memory located in the connection module. One embodiment of a method of this type will be described in greater detail below with reference to the fieldbus coupler shown schematically in  FIG. 5 . 
         [0050]    For example, once the main module  20  is started, the control unit  200  accesses the interface driver  202  to query whether a connection module  10  is connected with the plug connector  26 . If a connection module  10  is connected, the interface driver  202  establishes a communication link, via the mating connector  26  and the plug connector  16 , to interface driver  102  for non-volatile memory  103 . The link between the two interface drivers  102  and  202  can be based on a known protocol, for example according to the USB (Universal Serial Bus) specification. Once the presence of a connection module  10  has been detected and a communication link between interface drivers  102  and  202  has been established, microcontroller  200  accesses the content of non-volatile memory  103 . It should be noted that, in further embodiments of the connection module  10 , the non-volatile memory  103  can be coupled to the plug connector  16  directly, that is, without the interface driver  102 . The non-volatile memory  103  is then addressed directly by main module  20 . 
         [0051]    On the basis of compatibility data that are stored in the non-volatile memory  103 , control unit  200  then determines whether the connected connection module  10  is compatible with the main module  20 . The non-volatile memory  103  may also contain license data, which can be used to determine whether main module  20  is licensed for use with the fieldbus that can be connected to fieldbus port  12  of connection module  10 . 
         [0052]    The non-volatile memory  103  may also contain program segments or programs, which can be input by the control unit  200  and can be used to update control programs, for example the firmware of the control unit  200  of the main module  20 . Firmware of this type is stored in the memory  203  of the main module  20  and is updated appropriately using the information from the non-volatile memory  103 . As a result, a newer connection module  10  for a newer or updated fieldbus variant can also be connected to an older main module  20 , the software of which is not configured for use with a certain fieldbus type. Once the connection module  10  has been connected, the software of the main module  20  is updated automatically, so that the main module is configured for use with the connection module  10 . 
         [0053]    To prevent any tampering with the connection module  10 , the non-volatile memory  103  can be permanently soldered to a circuit board of the connection module  10 . Furthermore, relevant information, for example regarding compatibilities and/or license data, can be stored in the non-volatile memory  103  in encrypted form. Decryption is preferably carried out by the control unit  200  once the content of the memory  103  has been read out using key data stored in main module  20 , for example in the memory  203 . 
         [0054]      FIGS. 6 to 8  show a further embodiment of an automation device according to the present invention. In this embodiment, the automation device is a control computer  30 , which is connected to a connection module  10  which provides fieldbus ports  12 , as in the embodiments described above. 
         [0055]    As with the automation device shown in  FIGS. 1 to 5 , the automation device embodied as a control computer has a main module  30 , which is mechanically and electrically coupled to connection module  10 . 
         [0056]    The control computer communicates with field devices through which signals can be output or input. The field devices are connected via the fieldbus ports  12 , either directly or indirectly via a fieldbus coupler such as the fieldbus coupler shown in  FIGS. 1-5 . 
         [0057]    A main module  20  of a fieldbus coupler according to an embodiment of  FIGS. 1 to 4  is also connected directly to the main module  30  of the control computer. This is possible because the control computer main module  30  is equipped on its side that is opposite the connection module  10  with a plug connector, not shown, which engages in the mating connector  26  of the fieldbus main module  20 . As a result, information that is usually exchanged between the control computer and the fieldbus coupler via the fieldbus can be transferred directly between the main module  30  of the control computer and the main module  20  of the fieldbus coupler. This results in a compact automation system which includes both the control computer and a fieldbus coupler, to which corresponding bus-capable modules can be connected. 
         [0058]    The system including the control main module  30  with the connection module  10  and with the main module  20  of the fieldbus coupler coupled thereto is shown in  FIG. 6 a    in an assembled state and in  FIG. 6 b    with the modules detached from one another.  FIG. 7  is a side view of the detached modules, and  FIG. 8  is a plan view of the modules in the assembled state. 
         [0059]    In the embodiment shown in  FIGS. 6 to 8 , a multi-part housing is used for the main module  30 , the housing including an upper section  31  and a lower section  33 . Connection  32 , display  38  and adjustment elements  40  are provided on the top surface of the housing upper section  31 , similar to the main module  20  of the fieldbus coupler. For example, in addition to light-emitting diodes as status displays, a display field is shown, along with a USB port and a miniature joystick that can be finger-actuated for manipulating the system. 
         [0060]    The side of the housing lower section  33  that faces the connection module  10  is similar in configuration to the housing lower section  23  of the fieldbus coupler main module  20 . On the opposite side, the housing lower section  33  is similar in configuration to the corresponding side of the connection module  10 , allowing it to be coupled to the fieldbus coupler main module  20 . As is clear from the plan view in  FIG. 8 , an unlocking lever  35  is provided with which the main module  30  can be locked onto a snap-on mounting rail. The snap-on mounting rail recess of the main module  30  is not visible in  FIG. 8 . 
         [0061]    Regarding the method of operation, reference is made to the description relating to  FIG. 5 . When operated as an automation device, information regarding the compatibility of the modules, licenses, and/or software updates of firmware in main module  30  can be input via the integrated non-volatile memory by main module  30 . 
         [0062]    While the preferred forms and embodiments of the invention have been illustrated and described, it will be apparent to those of ordinary skill in the art that various changes and modifications may be made without deviating from the inventive concepts set forth above.