Patent Publication Number: US-2021185052-A1

Title: Device for a secure data connection of at least one manufacturing machine

Description:
The invention relates to a device for a secure data connection of at least one manufacturing machine and a manufacturing machine having such a device and a production plant having several such manufacturing machines. 
     In production companies, manufacturing machines are regularly integrated into an operational process based on the “automation pyramid” known from the state of the art, which is subdivided into different levels and which permits information to be transferred only in the vertical direction of its levels, wherein any information exchanged with external service providers happens via the highest level of the pyramid, i.e. at the enterprise resource planning (ERP) level. As a part of “Industry 4.0”, however, a direct connection of manufacturing machines to external data processing devices, such as computers of a cloud (cloud computing) or, with regard to the company operating the machine, to computers of other companies, is increasingly desired at the individual levels of the automation pyramid in the horizontal direction, without including further levels of the pyramid. However, in the case of such a direct connection of a manufacturing machine to an external data processing facility, means must be provided to protect the manufacturing machine from access by third parties. 
     From US 2015/0106912 A1 a device for a secure data connection of at least one manufacturing machine to an external (with respect to the manufacturing machine and with respect to the company operating the manufacturing machine) data server is known, having a controller formed as an integral component of the manufacturing machine, wherein on said controller software for data processing of the machine data of the manufacturing machine, in particular for buffering, forwarding and/or compression, is implemented, and wherein said controller is connected via an external (with respect to the manufacturing machine) firewall to a machine network, in which a plurality of manufacturing machines are provided, wherein said machine network via a further external (with respect to the relevant manufacturing machine) firewall is connected to the external data server, which is connected to the Internet. 
     Access control to the controller of the manufacturing machine, for the remote servicing for troubleshooting by an expert via the Internet, in one exemplary embodiment is implemented by an encryption and in a further exemplary embodiment by an upload of the machine data from the controller, without any data backflow, solely in the direction of the expert&#39;s company-external computer, wherein the upload of data denotes the transfer of data from a local computer or storage medium to a computer or storage medium remote from the local computer or storage medium. 
     An alteration affecting the machine control, such as a write access to the controller of the manufacturing machine, originating from an external (with respect to the manufacturing machine and/or to the company operating the machine) computer, wherein said alteration may have adverse effects on the product manufactured by the machine, cannot be completely ruled out by the known solution, e.g. because of a security gap, a software or hardware error (Spectre and Meltdown) and/or a flawed configuration of the firewalls. 
     Starting from this prior art, the invention addresses the problem of further improving the known solution such that the operational safety of the manufacturing machine is increased. 
     This problem is solved by a device for a secure data connection of at least one manufacturing machine, according to the invention, having the features of patent claim  1 . 
     According to claim  1 , the device according to the invention has a system that is subdivided into individual zones interconnected by data diodes such that data originating from the machine control of the manufacturing machine in a data flow can be transferred to other zones without the possibility of data backflowing, wherein said zones, ordered hierarchically, each have a lower level of data security than the upstream zone with respect to the data flow, and that every zone is formed as an independent computer in the manner of an isolated application. 
     The design of every zone in the manner of an island solution as an independent computer is defined as every computer being independently functional with regard to its hardware and software and being formed to be separate from the other computers at the hardware and software level, in particular spaced apart. 
     The information processing system is divided into zones, each of which is formed as an independently functioning computer in terms of software and hardware. By separating the zones at the software and hardware levels, an extremely effective access control can be set up in terms of security for read and/or write access of external (with regard to the manufacturing machine) data processing devices to the data originating from the machine control of the manufacturing machine. 
     In concrete terms, different zones of the information processing system having different levels of data security, i.e. data criticality, can be defined, which can be used to grant access rights in the form of either read and write access or read-only access to an individual external (with respect to the manufacturing machine) data processing device, in accordance with the data security of the individual zone connected to the data processing device. Thus, in the case of access of a data processing device to the zone having the highest level of data security, the data originating from the machine control of the manufacturing machine can be both changed in the sense of a write access and readable, and in the case of access to a zone having lower level of data security in relation to this zone, because of data transmission without any data return flow, i.e. unidirectional data transmission, from the zone having the highest level of data security in the direction of the zone having lower level of data security in relation thereto, the data can be read only and cannot be changed in the sense of a write access, i.e. is immutable by means of a write access. 
     As a result, a respective zone, subordinate to the zone having the highest level of data security and having a lower level of data security in relation to the latter, can be connected to an external data processing device without the possibility of write access to the data of the zone having the highest level of data security, originating from the machine control of the manufacturing machine. This increases the operational reliability of the manufacturing machine. 
     In a preferred exemplary embodiment, the first zone downstream of the machine control can, as the production zone, process at least machine data of the manufacturing machine and forward them to a monitoring zone and/or a service zone as the respective downstream zone, wherein said machine data can be forwarded to an company-internal or external network, such as the Internet. In this case, the respective network is formed as an company-internal or a (company-)external network, with regard to the company operating the manufacturing machine. 
     By data transmission can the production zone of the one machine control is connected to machine controls of other manufacturing machines within a production plant. 
     The production zone permits at least one of the data processing operations listed below: Data processing of data of the manufacturing execution system (MES) of a manufacturing management system and/or data processing of data collected over a period of time, and/or generation of production logs and/or reports. The MES is a process-related level of a manufacturing management system or production control system that can be represented schematically by the automation pyramid known from the state of the art. Here, the production management system or production control system is based on the product produced by the manufacturing machine. 
     The monitoring zone may permit at least one of the data processing operations listed below: Generating a data overview of a manufacturing machine, and/or detecting trends, and/or recording the operating state of the machine. 
     The service zone may permit at least one of the data processing operations listed below: Data processing of maintenance data, and/or recording the machine operating state, and/or performing remote diagnostics. 
     Data transmission between the individual manufacturing machines of a production plant can at least permit the transmission of the data listed below: Data of the Manufacturing Execution System (MES) of the manufacturing management system, and/or data collected over a period of time. 
     The company-internal network may at least permit the transmission of the data listed below: Data to generate an overview of multiple manufacturing machines, and/or data of mobile devices. 
     The external network can, preferably involving the cloud, at least permits the transmission of data for maintenance scheduling, and/or a creation of directories and/or documentation records and/or a link between real machine data and documentation in the cloud. This applies in particular to services offered by the machine manufacturer. Further applications are e.g. machine monitoring or predictive maintenance. 
     The respective data diode used between the individual zones having their computer units can be formed by a laser diode, which is used for light generation, and a photo diode, which is used for light detection of the generated light. 
     The zones, at least partially interconnected in parallel, can be connected in series with the first zone with respect to the data flow, and/or can be at least partially connected in series, starting from the first zone. 
     Every zone can comprise on the input end at least one protocol converter for protocol conversion and coupling of a data transfer protocol that can be transmitted by means of the data diodes to a data transfer protocol that can be processed by the zones and/or can comprise on the output end at least one further protocol converter for protocol conversion and coupling of a data transfer protocol that can be processed by the zones to a data transfer protocol that can be transmitted by means of the data diodes. 
     The computers can be formed identically, in particular with regard to their hardware and/or operating software, and can be configured for their intended use, in particular by means of application software, in accordance with the individual zone. 
     A data diode may be formed by a transmitting unit, which is part of a respective zone, and a receiver unit, which is part of a zone having a lower level of data security in relation to that zone, wherein a data transmission means is used to interconnect the transmitting unit and the receiver unit. 
     The transmitting unit may be formed as a transmitting data diode comprising a laser diode and, in particular, a multiplexer and a modulator, wherein the receiver unit may be formed as a receiving data diode comprising a photo diode and, in particular, a demodulator and a demultiplexer, and wherein the transmitting unit and the receiver unit are interconnected via the data transmission means in the form of an optical fiber cable. 
     According to claim  16 , the subject matter of the invention is also a manufacturing machine having, as an integral part thereof, a device according to any one of the preceding claims. The solution according to the invention is particularly suitable for use in blow molding, filling and sealing machines. These are regularly used in the chemical-pharmaceutical and food industries. 
     According to claim  17 , the subject matter of the invention is also a production plant comprising a plurality of manufacturing machines according to claim  16 . 
     The device according to the invention can be used to particular advantage in companies in which a manufacturing machine must meet above-average safety requirements due to mandatory official regulations. 
     In such a case, for any change affecting the machine, a producer operating the manufacturing machine has to demonstrate that a particular change affecting the machine will not have any adverse effects on the product produced by the machine. Such a change can be, for instance, a connection of the machine to an external data processing device or an installation of an application software on the controller, i.e. the industrial control system, of the machine. 
     In addition, on the basis of the regulatory requirements the software services running on the controller of the machine, i.e. the various types of application software, depending on whether they relate to components and processes of the machine that have to be validated or are validated or do not have to be validated, are classified as Good Manufacturing Practice (GMP)-relevant software services subject to regulatory requirements or as non-GMP-relevant software services hardly subject to regulatory requirements, wherein write access by non-GMP-relevant software services to validated components or processes of the machine must be precluded mandatorily. 
     Therefore, in such “regulated companies”, after any such alteration the components and processes of the machine affected by these changes have to be validated based on test procedures and risk assessments, which is time-consuming and costly. However, even such test procedures or risk assessments cannot completely rule out adverse effects on the product manufactured by the machine because of access to the controller of the manufacturing machine from an external (with regard to the manufacturing machine) data processing device or because of newly installed application software. 
     Based on the design of the device according to the invention validation processes in the form of risk assessments and/or test procedures are at least partially eliminated, because the zone subordinate to the zone having the highest level of data security and having a lower level of data security in relation to it, can be connected to an external data processing device, without the possibility of write access to the data, originating from the machine control of the manufacturing machine, of the zone having the highest level of data security, and because the GMP-relevant application software can run in a zone having a higher level of data security and the non-GMP-relevant application software can run in a zone having a lower level of data security. 
     As a result, when the device according to the invention is used in combination with a manufacturing machine subject to official regulations, modifications affecting the manufacturing machine can be performed simply and inexpensively, in particular with regard to the connection of the manufacturing machine to external data processing equipment and/or the implementation of application software for the manufacturing machine, while complying with the relevant official safety requirements. 
    
    
     
       Below, the device, according to the invention, for the secure data connection of at least one manufacturing machine is explained in more detail with reference to the drawing. In the figures, in general view, not to scale, 
         FIG. 1  shows a schematic block diagram of a device for the secure data connection of at least one manufacturing machine, known from the prior art; 
         FIG. 2  shows a schematic block diagram of a device for the secure data connection of at least one manufacturing machine, according to the invention; and 
         FIG. 3  shows a schematic block diagram of the data flow of the device according to the invention of  FIG. 2  from an application software implemented on one zone to an application software implemented on another zone. 
     
    
    
       FIG. 1  shows a schematic block diagram of the device, known from the prior art (US 2015/0106912 A1), for connecting at least one manufacturing machine  4  to an external (with regard to the manufacturing machine  4  and with regard to the company  6  operating the manufacturing machine  4 ) data processing device in the form of a data server  8 . The device comprises a controller  10 , i.e., the controller of the machine, which is formed as an integral part of the manufacturing machine  4  and on which software  14  for data processing of the machine data of the manufacturing machine  4 , in particular for buffering, forwarding and/or compressing, is implemented and which is connected to an company-internal machine network  18  via a firewall  16 , which is external with respect to the manufacturing machine  4  and company-internal with respect to the company operating the manufacturing machine. In the company-internal machine network  18  a plurality of manufacturing machines  4  are provided and the company-internal machine network  18  is connected to the company-external data server  8  via a further company-internal firewall  20  and via a company-external network  22 . The network  22  can be connected to a remote service not shown in the figures by means of the Internet  24 , wherein in the context of a remote service an expert working remotely from the company operating the manufacturing machine troubleshoots the manufacturing machine by means of a computer via the Internet  24 . 
     Access control to the controller  10  of the manufacturing machine  4  for performing the remote service is implemented by encrypting or uploading the machine data from the controller  10  solely towards the company-external computer of the expert, without any data backflow. 
       FIG. 2  shows a schematic block diagram of a device according to the invention, which can be designated as a multi-zone computing platform, for connecting at least one manufacturing machine  104  to external (with respect to the manufacturing machine  104 ) data processing devices not shown in the figures. The manufacturing machine  104  may be manufactured and delivered in conjunction with the device as an integral part of the manufacturing machine  104 , or it may be subsequently equipped with the device after the manufacturing machine  104  has been delivered. 
     The device according to the invention has an information-processing system  114  divided into three individual zones  108 ,  110 ,  112  ( FIG. 2 ) in the form of computers, wherein every computer is independently functional in terms of its hardware and software and is formed to be separate at the hardware and software level, and, in particular spatially, separated from the computers of the other zones  108 ,  110 ,  112 . In addition, the computers correspond to each other in terms of their hardware and their operating software and can each be configured for use as intended in accordance with the individual zones  108 ,  110 ,  112  by means of application software  122 ,  124  ( FIG. 3 ) (Application Software, App). The application software  122 ,  124  may be used, for instance, for data conversion, data processing, or data forwarding. 
     A first zone  108  ( FIG. 2 ) is connected to the machine control  118  of the manufacturing machine  104  via a data link  116 , in particular a bidirectional data link  116 , and is used to process data transmitted by the machine control  118  via the data link  116 . In addition, the first zone  108  may be connected, in particular bidirectionally, to the machine control of at least one other manufacturing machine via a network, wherein all manufacturing machines connected to the first zone  108  via the network are provided within a production plant. In addition, in the sense of a series connection, the first zone  108  is connected to a second zone  110  and the second zone  110  is connected to a third zone  112  by one unidirectional data link each, in the form of a data diode  120 , whereby the direction of the data flow of the machine control data  118  located in the first zone  108  from the first zone  108  to the second zone  110  and from the second zone  110  to the third zone  112  is predetermined, wherein a backflow of data from the third zone  112  into the second zone  110  and/or from the second zone  110  into the first zone  108  is completely precluded. In the direction of the data flow, the zones  108 ,  110 ,  112 , starting from the first zone  108  having the highest level of data security, i.e. data criticality, arranged in a hierarchically descending manner, each have a lower level of data security than the at least one upstream zone  108 ,  110  with respect to the data flow, such that the last zone of the hierarchically descending series circuit, i.e., the third zone  112  in  FIG. 2 , has the lowest level of data security. 
     Every zone  108 ,  110 , in particular a transmitting unit  128  ( FIG. 3 ) of the respective zone  108 ,  110 , comprises at least one configurable filter module on the output end, which provides at least one predefinable, unfiltered subset of a data quantity of the respective zones  108 ,  110  for transmission by means of the respective data diode  120  to a zone  110 ,  112  having a low level of data security. The filter module can be used to select which data may leave a respective zone  108 ,  110  and be made available to the downstream zone having the lower level of data security. 
       FIG. 3  shows schematically in a principal block diagram the data flow from a respective zone  108 ,  110  to another zone  110 ,  112  of the device according to the invention, on each of which different types of application software  122 ,  124  are implemented. The data processed by respective application software  122 ,  124  implemented in the zone  108 ,  110  having the higher level of data security is first transmitted to one of a plurality of protocol converters  126  provided in this zone  108 ,  110 , wherein said protocol converters  126  serves for protocol conversion and coupling of a data transfer protocol that can be processed by the zone  108 ,  110  having the higher level of data security to a data transfer protocol that can be transmitted by means of the data diode  120 . The protocol-converted data are transferred from the protocol converter to a transmitting unit  128 , provided in the zone  108 ,  110  having the higher level of data security, of the data diode  120 , which has a multiplexer  130 , the output end of which is connected to a modulator  132  of the transmitting unit  128 , wherein said modulator  132  transfers the modulated data to a laser diode  134  included in the transmitting unit  128  to generate a light signal. 
     The multiplexer  130  is provided by the layer  2   a  in the form of the MAC (Media Access Control) layer according to the  051  model (Open System Interconnection Model) known from the prior art, wherein said layer may additionally comprise a data flow control system and is part of the layer  2  in the form of the data link layer according to the  051  model. The multiplexer  130  can be used to transmit the data, provided by the protocol converters  126 , in the form of corresponding different data streams via a single channel in the form of the data diode  120 . The modulator  132  is provided by the layer  1  in the form of the physical layer according to the  051  model and is used to encode the data present digitally in the zones  108 ,  110  having the higher level of data security, into modulated analog data that can be transmitted using the data diode  120 . The laser diode is part of an Ethernet transceiver, e.g. SFP (Small Form-Factor Pluggable) or SFP+, which is used as an optical fiber network interface and whose data receiving port Rx is blocked. 
     The zone  110 ,  112  having the lower level of data security ( FIG. 3 ) has a receiver unit  136  of the data diode  120 , which is connected to the transmitting unit  128  of the zone  108 ,  110  having the higher level of data security by a data transmission means  138  in the form of an optical fiber cable  140 , which transmits the light signal comprising data and emitted from the laser diode  134  of the transmitting unit  128  to the receiver unit  136  of the data diode  120 , which comprises a photo diode  142  for detecting the light signal. In addition, the receiver unit  136  has a demodulator  144 , into which the data stream received from the photo diode  142  is input at the input end and which passes the demodulated data at the output end to a demultiplexer  146  of the receiver unit  136 , which on the output end transmits the data processed thereby to at least one protocol converter  126 , in each case for protocol conversion and coupling of the data transfer protocol that can be transmitted by means of the data diode  120  to the data transfer protocol that can be processed by the zone  110 ,  112  having the lower level of data security. Every protocol converter  126  provides the converted data to various types of application software  122 ,  124  for further processing. 
     The photo diode  142  is part of an Ethernet transceiver (e.g. SFP or SFP+) that serves as an optical fiber network interface and whose data transmitting port Tx is blocked. The demodulator  144  is provided by the physical layer according to the OSI model and is used to decode the modulated analog data that can be transmitted by the data diode  120  into digital data that can be processed by the zone  110 ,  112  having the lower level of data security. The demultiplexer  146  is provided by the MAC layer according to the  051  model and is used to separate the data streams combined by the multiplexer  130  of the transmitting unit  128 . 
     In  FIG. 2 , the first zone  108  is a production zone, the second zone  110  is a monitoring zone, and the third zone  112  is a service zone. 
     The MES interface  148  of the production zone  108  ( FIG. 2 ) can be connected via an company-internal (with respect to the company operating the manufacturing machine  104 ) manufacturing network  150 , e.g. via a local area network (LAN), to a computer of the manufacturing execution system (MES)  152  of the manufacturing management system for managing the production of the product manufactured by means of the manufacturing machine  104  and/or the database interface  154  of the production zone can be connected via the manufacturing network  150  to a computer of a data storage device  156 , on which machine data collected over a period of time, in particular a long period of time, are stored or buffered and from which they can be retrieved. The MES  152  can be used to automatically control several manufacturing machines  104  of a production plant at the same time, permitting the production process to be streamlined and human errors, such as typing errors, to be minimized. Setpoints, process values, alarms, and/or events can be stored on the data storage device  156  for long-term storage, or data can be buffered, in particular using OPC Historical Data Access (HDA), for a short time. In addition to processing data from the machine control, the production zone  108  is used to forward such data to the computer of the MES  152  and/or to the computer of the data storage device  156 , and to process data transmitted from the computer of the MES  152  and/or from the computer of the data processing device  156 . Data processing includes the generation of production logs  174  and reports  174 . 
     The monitoring zone  110  ( FIG. 2 ) can be connected via a company-internal (with respect to the company operating the manufacturing machine  104 ) office network  158 , for instance via a further local area network (LAN) to a computer, on which a data overview  164  of data of all manufacturing machines  104  of the production plant can be generated, and/or to mobile terminals  162 , for instance a tablet, a laptop and/or a smartphone. The monitoring zone  110  ( FIG. 2 ) is used to generate a data summary  160  of the data of a manufacturing machine  104  to detect trends  178 , and to record the operating state  176  of the manufacturing machine  104 , each computed from data transmitted from the machine control  118  of the manufacturing machine  104  to the monitoring zone  110 . 
     Using the data summary  160 , the efficiency of the manufacturing machine  104  can be monitored and less efficient components can be identified. In addition, a particularly good overview of the manufacturing machine  104  can be obtained by means of the data overview  160  when the key performance indicators are displayed. The browser of the terminal devices  162  can be used to access the data overview  160 . 
     The service zone  112  ( FIG. 2 ) can be connected via a external network  166 , for instance via a wide area network (WAN), preferably via the Internet, particularly preferably using cloud computing, to a computer for creating a directory  168  and/or a documentation  168 , and/or via the external network  166  by means of a maintenance interface  170  to a computer of the manufacturer  172  of the manufacturing machine. The directories  168  and/or documentation  168  can be located in the cloud (cloud computing) and can include lists of spare parts of the manufacturing machine  104 . The documentation  168  includes technical information about the manufacturing machine  104  and its associated components, in particular the device according to the invention. The service zone  112  is used to record the operating state  176  of the manufacturing machine and/or to perform remote diagnostics  180 . The machine manufacturer can provide the producer with troubleshooting assistance within the framework of remote diagnostics  180 . 
     Example applications of the device according to the invention and its advantages are discussed in more detail below: 
     Remote diagnosis: By introducing a service zone  112 , the machine manufacturer  172  can provide remote diagnostics  180 , which does not impose any additional risk or validation burden on the producer. In this case, access by the manufacturer  172  is limited to a subset of the data from the service zone  112  by means of the data filter. 
     Machine optimization: By introducing a service zone  112  in the manufacturing machine  104 , usage data of the machine  104  can be recorded and transmitted to the machine manufacturer  172 . These data can be used as a basis for further developments and improvements of the machine manufacturer  172 . It can be used to better adapt future machine generations to the actual usage behavior of customers. 
     Efficiency Data Record: The formation of different zones  108 ,  110 ,  112  permits the efficiency data to be made available on the office network  158  or a cloud service. The recording of efficiency data of production lines and machines  104 , e.g. Overall Equipment Effectiveness (OEE), permits the producer to evaluate process changes and identify improvement potentials. In particular, the recording of key figures is not necessarily GMP-relevant. Thus, the key figure recording does not require write access to the production zone  108 , but only to the relevant information. In this respect, the key figures can be acquired and evaluated in a separate zone  110 ,  112 . 
     Scheduling maintenance: Setting up of different zones  108 ,  110 ,  112  permits runtime information to be provided, improving the scheduling of maintenance work. For instance, the scheduling of maintenance activities on a manufacturing machine  104  ideally requires data on the operating time or cycles of operation of individual components or assemblies, e.g. a valve has to be replaced after a certain number of switching cycles or a seal after a certain number of operating hours. On the one hand, the machine manufacturer  172  can use runtime information to prepare deliveries of spare parts even before the producer orders them or to inform the producer about upcoming maintenance work; on the other hand, the producer can use such information to arrange a more efficient maintenance schedule. 
     Predictive Maintenance: The data-supported analysis of machine data, e.g. the switching time of valves, based on different zones  108 ,  110 ,  112  can be used to estimate when a component has to be replaced. For this purpose, the device permits local processing in a non-production zone, i.e., the monitoring zone  110  or the service zone  112 . Additionally, the corresponding application software  122 ,  124  ( FIG. 3 ) can be coupled to external services. 
     Pre-validation of application software: Because of the different zones  108 ,  110 ,  112  newly installed application software  122 ,  124  ( FIG. 3 ) can be run in a non-production zone, e.g. in the monitoring zone  110  or in the service zone  112 , in parallel with the application software  122 ,  124  used, wherein the software  122 ,  124  is supplied with identical production data in both zones  108 ,  110 ,  112 , which can be used to check whether the newly installed application software  122 ,  124  provides the same results as the application software  122 ,  124  already implemented. In this way, tests whether the newly installed application software  122 ,  124  is a hazard to the integrity, safety and/or productivity of the production plant can be conducted during operation. 
     Production logs: The different zones  108 ,  110 ,  112  can be used to generate logs  174  ( FIG. 2 ) and reports  174  in the monitoring zone  110  or in the service zone  112 , because processing production information, e.g. the generation of production logs  174 , does not require access to the production zone  108 , only to machine data. 
     GMP Documentation: By separating the GMP-relevant and the non-GMP-relevant software  122 ,  124  into different zones  108 ,  110 ,  112 , the scope of the required GMP documentation can be reduced to the GMP-relevant software  122 ,  124  in the production zone  108 . 
     Secure connection of alarms via insecure networks  166 : The device permits alarms, status messages and other information to be sent directly to end devices  162 , such as tablets, laptops and/or smartphones, via, in particular, insecure networks  166 , such as the Internet and/or mobile networks, without any security risk to the producer.