Patent Publication Number: US-2002006790-A1

Title: System and method for remote maintenance and/or remote diagnosis of an automation system by means of electronic mail

Description:
[0001] This is a Continuation of International Application PCT/DE99/03250, with an international filing date of Oct. 8, 1999, the disclosure of which is incorporated into this application by reference. 
    
    
     
       FIELD OF THE INVENTION  
       [0002] The invention relates to a system and method for remote maintenance and/or diagnosis of an automation system provided with an electronic firewall via a data transmission system.  
       BACKGROUND OF THE INVENTION  
       [0003] For remote maintenance and/or diagnosis, a special data connection is required between an automation system and a remote user intending to perform remote maintenance and/or diagnosis. Due to this special data connection that needs to be provided, remote maintenance and/or diagnosis is associated with high costs. Within corporate communications networks, data connections to an Intranet are frequently, i.e., to an internal corporate data network and/or to a worldwide data network, for instance the Internet. The internal data network is usually protected against the outside by a protective barrier, a so-called firewall, i.e., the data environment within the internal corporate communications network cannot be accessed from outside the internal communications network. If data within the communications network is to be accessed from outside the firewall, a stand-alone computer must normally be installed outside the firewall. U.S. Pat. No. 5,715,393, for instance, discloses a method for remote computer system monitoring via electronic mail.  
       OBJECTS OF THE INVENTION  
       [0004] An object of the invention is to provide a system and method for remote maintenance and/or diagnosis of an automation system. It is a further object to provide such a system and method which make it possible to easily provide remote maintenance or remote diagnosis even if an electronic firewall surrounds the automation system.  
       SUMMARY OF THE INVENTION  
       [0005] According to one formulation of the invention, the invention is directed to a data transmission system for at least one of remote maintenance and diagnosis of an automation system that is provided with an electronic firewall. The transmission system includes a first transmit/receive device and a second transmit/receive device. The first transmit/receive device is disposed at a location of a remote user that sends a first e-mail message, via a data transmission system, to the automation system. The first transmit/receive device includes an instruction encoder, which packages at least one instruction in the first e-mail message. The second transmit/receive device is disposed at a location of the automation system to receive the first e-mail message sent by the remote user. The second transmit/receive device includes an instruction decoder which automatically identifies the instruction in the first e-mail message, and which transmits the instruction to an application of the automation system for which the instruction is intended.  
       [0006] The invention is based on the realization that access to devices of an automation system is possible even behind an electronic firewall, if the desired control instructions are packaged in an e-mail message. To this end, at the location of a remote user intending to perform remote maintenance or remote diagnosis of an automation system, a desired instruction is packaged into the e-mail message to be transmitted. It is then addressed and sent to the automation system. The addressee within the automation system receives and decodes the e-mail message, that is, the addressee extracts the control instruction from the e-mail message, and forwards it to an application for which the control instruction is intended. This makes it possible for the remote user to initiate commands and, for instance, transmit data for the automation system without the requirement of a separate and costly data connection between the remote user and the automation system. Additionally, the firewall surrounding the automation system does not present an obstacle for the electronic mail.  
       [0007] In analogous fashion to the transmission of the instruction, a reply may be sent to the remote user, in that the second transmit/receive device is provided to accept information, which is determined by the application as a result of the instruction, and to transmit the information in the form of electronic mail to the first transmit/receive device of the remote user. Consequently, the remote user is not only able to control the automation system, but can also request, for instance, status information of the automation system. This renders it possible actually to operate and monitor the automation system from the remote location.  
       [0008] Security against unauthorized penetration of the firewall of the automation system is ensured by an encryption device used to encrypt the information transmitted from the second transmit/receive device to the first transmit/receive device. A decryption device at the location of the remote user is used to decrypt the information. This ensures that only the user possessing the associated key can read, transmit and receive control data to and from the automation system. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.  
     [0010]FIG. 1 is a block diagram of an embodiment of a system for remote maintenance and diagnosis of an automation system,  
     [0011]FIG. 2 a  is an embodiment of the basic structure of an electronic mail message for remote maintenance,  
     [0012]FIG. 2 b  is an embodiment for the basic structure of a result message, and  
     [0013]FIG. 3 is a schematic representation of a process sequence for remote maintenance and remote diagnosis, according to the present invention.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0014]FIG. 1 shows an embodiment of a system for remote maintenance and diagnosis of an automation system via a data transmission system  18 . The data transmission system  18  is connected via an Internet  4  with remote users  1 ,  19 ,  20  as well as with automation system  2 . At the location of the remote user  1 , a computer  23  is provided, which has a first transmit/receive device  3 . The computer  23  is coupled with a monitor  7  and a keyboard  25 . The first transmit/receive device  3  has an instruction encoder  10 , which is used to package an instruction in an electronic or e-mail message  16  to be transmitted. In addition to the instruction encoder  10 , the first transmit/receive device  3  has an encryption/decryption device  22  to encrypt the instruction that is packaged in the e-mail message  16 .  
     [0015] At the location of the automation system  2 , a second transmit/receive device  5  is provided for receiving and transmitting electronic messages  16 ,  17 . The second transmit/receive device  5  has a decoder  11  that is used to decode the instruction contained in a received e-mail message  16 . An instruction  8 , extracted in this manner, is then forwarded via a decryption device  21  to an application  6  for which the instruction  8  is intended. Likewise, it is also possible, according to the present invention, to send information from the location of the automation system  2 , in the form of an e-mail message  17  via the Internet  4  of the data transmission system  18 , to the remote user  1 ,  19  and/or  20 . At the location of the automation system  2 , an electronic firewall  12  is provided, which prevents direct access from the outside to the automation system  2 , but which is penetrable for the receipt or transmission of e-mail messages  16 ,  17 .  
     [0016] By means of the system for remote maintenance and/or remote diagnosis of the automation system  2  protected by the electronic firewall  12  as depicted in FIG. 1, simple commands may be executed by the remote user  1 ,  19  and/or  20  and data may be transmitted from the automation system  2  to the remote user  1 ,  19  and/or  20 . This will now be described in greater detail with the aid of the remote user  1 . For remote maintenance and/or diagnosis from the location of the remote user  1 , the computer  23  along with the keyboard  25  and the monitor  7  coupled to the computer  23 , are used to call up the first transmit/receive device  3 , with for instance a correspondingly adapted standard e-mail tool, such as Microsoft Exchange, etc. An address of the automation system  2  is entered in the address field, and the application  6 , for which an executable command is intended, is entered in the subject field. The command itself is entered in the text field of the e-mail message and, if desired, is encrypted by the encryption device  22 . Encryption ensures that only the automation system possessing an associated key can read the corresponding data.  
     [0017] Subsequently, the composed e-mail message  16  is transmitted via the data transmission system  18 , in particular via the Internet  4 , to automation system  2 . The second transmit/receive device  5 , which is part of the automation system  2 , receives the e-mail message  16 . The transmitted command or instruction is decoded by the decoder  11  and possibly decrypted by the decryption device  21 . The command thus obtained is forwarded, for instance, to the application  6  indicated in the subject field of the e-mail message  16 , and is executed there. The execution may be for example, in the form of controlling, monitoring or operating the application of the automation system, depending on the format of the instruction. If the e-mail message  16  transmitted by the remote user  1  to the automation system  2  contains, for instance, an instruction  8 , which acts as a result generating means and causes a result  9  to be generated in the application  6 , the result  9  determined by the application  6  is transmitted in a reverse direction, in the form of the e-mail message  17 , to the data transmission system  18  by the second transmit/receive device  5 . If appropriate the result data  9  is encrypted by the second encoder  11  and the second encryption device  21 . The e-mail message  17  containing the result data  9  of the application  6  is received, decoded and decrypted by the remote user  1 . Thus, system shown in FIG. 1 makes it possible to access devices within the firewall  12  by means of so-called e-mail tunneling. Access is possible from any Internet connection, so that, for instance, remote maintenance and/or remote diagnosis of the automation system  2 , in case of a malfunction of the automation system  2 , is possible irrespective of the location of a specialist.  
     [0018]FIG. 2 a  shows an embodiment of the basic structure of an e-mail message  16 , such as it may be displayed, for instance, on the screen of the monitor  7  (compare with FIG. 1). The e-mail message  16  has an identification field  30  and a text field  29 . The identification field  30  contains an address field  26 , a sender field  27 , a date and time field  31 , and a subject field  28 . The address field  26  serves to indicate the recipient. The sender field  27  identifies the sender, i.e., the remote user sending e-mail message  16 . The subject field  28  contains, for instance, a keyword and/or information identifying the special application  6  (compare with FIG. 1) of the automation system. The text field  29  contains the instruction or instructions that are to be transmitted to the application  6 .  
     [0019] The structure of the e-mail message  16  shown in FIG. 2 a  corresponds to the familiar structure of known e-mail tools, such as Microsoft Exchange. This known structure is adapted to the special tasks of remote diagnosis or remote maintenance in that the address field  26  contains the recipient, i.e., the automation system  2 , and the subject field  28  contains the special application  6  for which the instruction  8  is intended. As previously mentioned in connection with FIG. 1, the instruction  8  provided in the text field  29  may be encrypted. To generate such an e-mail message for remote maintenance or remote diagnosis, the remote user  1  (compare with FIG. 1) uses a special remote maintenance mail tool, which automatically packages the instructions  8  to be transmitted in the e-mail message  16  using a corresponding instruction encoder (compare with FIG. 1).  
     [0020]FIG. 2 b  shows the basic structure of a result message  17 . The basic structure of the electronic or result message  17  corresponds to that of the electronic or instruction message  16  (compare with FIG. 2 a ). For instance, result message  17  again has an identification field  30 ′ and a text field  29 ′. An address field  26 ′ in the result message  17  indicates the addressee, for example “remote user  1 ,” while a sender field  27 ′ identifies the sender, in this case “automation system  2 .” A subject field  28 ′ contains the information comprised in the subject field  28  of the message  16  sent by the remote user, which is merely supplemented by the addition RE (=answer). The text field  29 ′ in FIG. 2 b  contains specific information pertaining to the result message, i.e., status information regarding Port  1 , Port  2 , Port  3 , etc.  
     [0021] The result message  17  depicted in FIG. 2 b  is automatically generated in the automation system  2  (compare with FIG. 1) in response to the e-mail message  16  transmitted by the remote user  1  and is sent to the remote user  1  by the transmit/receive device  5  of the automation system  2  via the data transmission system  18 , in particular the Internet. This makes it possible for a remote user from any location connected to the data transmission system  18  to execute remote maintenance or remote diagnosis. The information contained in the text field  29 ′ may again be automatically encrypted.  
     [0022]FIG. 3 is a schematic representation of the process sequence for remote maintenance and remote diagnosis. A remote user  1 , in a first process step  32  and, using a so-called command or instruction encoder  10 , generates an e-mail message  16 , which contains a command  8 . In a second process step  33 , the e-mail message  16 , including the corresponding command  8 , is sent through a firewall  12  of an automation system  2 , for instance on the server of the automation system  2 . In a third process step  34 , by means of a so-called command or instruction decoder  14 , the incoming e-mail message  16  is automatically interpreted and the command  8  thus extracted is forwarded to the corresponding application  6  for execution. A so-called result encoder  13 , in a fourth process step  35 , accepts the result determined by the application  6 , and, in a fifth process step  36 , packages it in an e-mail message  17 . In a sixth process step  37 , the e-mail message  17  is returned to the remote user  1  and the result  9  is extracted from the e-mail message  17  by a result decoder  15  and is displayed to the remote user  1 .  
     [0023] In summary, one aspect of the invention thus relates to a system for remote maintenance and/or diagnosis of an automation system  2 , which is provided with an electronic firewall  12 . To access the automation system  2 , for instance via the Internet from any computer connected to the Internet, it is proposed to send an e-mail message  16  to the automation system  2  via a data transmission system  18  with a first transmit/receive device  3  arranged at the location of a remote user  1 . To this end, an instruction  8  to be executed at the location of the automation system  2  is packaged by an instruction encoder  10  in an e-mail message  16  to be transmitted. At the location of the automation system  2 , there is a second transmit/receive device  5  to receive the e-mail message  16  sent by the remote user  1 . This second transmit/receive device  5  has an instruction decoder  11 , which automatically identifies the instruction in the e-mail message  16  and forwards this instruction  8  to the application  6  for which the instruction  8  is intended. Another aspect of the invention relates to an associated method that can be carried out by such a system.  
     [0024] The above description of the preferred embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and its attendant advantages, but will also find apparent various changes and modifications to the structures disclosed. It is sought, therefore, to cover all such changes and modifications that fall within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof.