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Industrial Ethernet Book 103

Technology SIMATIC S7-1500 PLC and the MindSphere operating system, which are configured and programmed in the TIA Portal. This also means that the engineering data for the cloud connection is automatically contained in the project backup and can be duplicated on other controllers, an important advantage for manufacturers of standardized machines. Importance of security Security against attacks remains of utmost importance when it comes to intrinsic communication. Although the MindConnect FB library already features an encrypted transmission of data, the use of a separate communication module is recommended for maximum security, such as the CP 1543-1. This plug-in module for the SIMATIC S7-1500 decouples the cloud communication from the automation network as it provides a separate Ethernet interface. To fend off attacks on the CP, a firewall is integrated into the module. Denial of service attacks (DoS attacks) on the automation network can also be averted. In addition to the actual communication architecture, the information design has to be considered as well; put simply, this means the protocols to the cloud. From the perspective of a data analyst, proprietary data formats for devices or manufacturers are to be avoided at all costs to avoid complex normalizations in the cloud. Furthermore, it is important to also transport the semantic context of the PLC data to the cloud, i.e., the identifier, the data type and the location in the object model. Only in this way can a failsafe connection be realized, and with little effort. To this end, a common language in the Variations for cloud connectivity include MindConnect FB and CP 1543-1 (left) or an industrial IoT gateway (right). IIoT is required, which preferably is supported by all devices in the same way. The Unified Architecture of the OPC Foundation (OPC UA) offers the best conditions for it. OPC UA is non-proprietary, can be deployed on a variety of hardware platforms and operating systems, offers comprehensive services ranging from dynamic exploration of a device interface to powerful security functions and, above all, is supported by a broad alliance of manufacturers. Companion specifications A fundamental integral to the success of OPC UA, though, are industry-specific and application-specific supplementary standards, so-called companion specifications. This is where manufacturer consortia or industrial associations together with the OPC Foundation formulate specific versions of OPC UA to really make the different devices or applications interoperable. An example is a temperature probe manufacturer which can, of course, integrate its own object model into the sensor. But what is the symbolic name: “Temp”, “Temperature”, or just “t”? Is the value output in degrees Celsius, degrees Fahrenheit, or Kelvin? Is it an integer or a floating point value? Determinations of this kind are made in the companion specifications; only then does OPC UA become truly IoT-capable. One such companion specification was developed for AutoID devices (RFID or optical codes) by manufacturers such as Siemens and Harting together with the OPC Foundation. At the 2017 Hanover Messe, the OPC Foundation demonstrated the interoperability between the Simatic RF600 RFID reader and a device from another manufacturer. The development of these supplementary standards, though, is relatively complex and requires a group of manufacturers that jointly pushes forward the work. It will therefore still take some time until comprehensive OPC UA modeling for all devices and objects of a factory becomes available. Markus Weinländer, Product Manager, Siemens. As a common language, OPC UA can integrate all levels of the IIoT. 10 industrial ethernet book 11.2017 SOURCE: SIEMENS SOURCE: SIEMENS


Industrial Ethernet Book 103
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