In factory automation (FA) and process control, networks and protocols of the operation technology are more and more merged with those of the information technology (IT). The requirements of operational technology (OT) and IT are different. Modern networks and protocols for communication in FA and process control systems must take care of the coexistence and convergence between the IT and OT worlds. Due to historical developments, the standards for OT were and remain defined by the International Electrical Commission. The IT, on the other hand, is the domain of the International Telecommunication Union and the International Standard Organization (ISO), which takes over most of the standards in the communication field from the IEEE Standard groups 802. This paper provides an overview of the standardization bodies involved and provides examples on how different requirements introduced by OT and IT can coexist. The merging of OT and IT on an Ethernet network with time-sensitive networking is the key technology for real-time applications in the factory floor. The adoption of the industrial protocol OPC UA provides secure connections from the factory floor to automation cloud infrastructures. IO-Link wireless, as new standard for sensors and actuators in OT, provides coexistence mechanisms toward wireless standards in IT applications such as IEEE 802.11. These examples show that there are possibilities to coexist and even to merge the standards and technologies of OT and IT in a successful way.

The thirteen papers in this special section focus on the deployment of distributed computer systems in industry.

Nowadays, computer systems are presented in almost all types of human activity and they support any kind of industry as well. Most of these systems are distributed where the communication between nodes is based on computer networks of any kind. Connectivity between system components is the key issue when designing distributed systems, especially systems of industrial informatics. The industrial area requires a wide range of computer communication means, particularly time-constrained and safety-enhancing ones. From fieldbus and industrial Ethernet technologies through wireless and internet-working solutions to standardization issues, there are many aspects of computer networks uses and many interesting research domains. Lots of them are quite sophisticated or even unique. The main goal of this paper is to present the survey of the latest trends in the communication domain of industrial distributed systems and to emphasize important questions as dependability, and standardization. Finally, the general assessment and estimation of the future development is provided. The presentation is based on the abstract description of dataflow within a system.

This paper deals with Real-Time applications based on Profinet IO Real-Time Class 3. The industrial automation in some cases requires the precision of IO data timing well below the delivered cycle time on the bus. When using the Isochronous Real-Time protocol of Profinet, one single predefined time within a cycle time can be chosen for the inputs- and outputs. The work presented here, shows how the architecture of a Profinet device can be improved. The user can define the time of an input or output within the given time slot with an accuracy of 65 nanoseconds. Furthermore the feasibility of the proposed design is proven with several measurements and simulations.

PROFINET IO is designed with a modular structure of the IO devices. Certified modular PROFINET IO devices are usually shipped with a General Station Description (GSD) file that does not contain the actual module configuration of the IO device. With common appliances the modules must subsequently be configured manually in the engineering tool. This can become an elaborate task in large PROFINET IO installations and it would therefore be useful to have some tool support to automatically detect and import the actually installed modules in an IO device. As a solution we propose a GSD file generator that creates the GSD file with the actual module configuration by retrieving the real data from the device via SNMP. This paper presents the implemented mechanism and gives some attention to certification issues.

Fieldbus based automation solutions are widely accepted in industrial applications. In the last twenty years the number of Profibus nodes is growing every year with more than 5 millions nodes. The success of this technology is also based on a continuous development and adoption of new mechanism to increase the functionally of the fieldbus technology. One of the adopted features is the possibility to create isochronous automation systems. This paper shows how isochronous automation applications are implemented with Profibus and the performances which can be achieved. An outlook is given to the new Ethernet based fieldbus Profinet and the possibilities to reach the same performances as with the fieldbus.

In modern communication systems based on Ethernet technology, the use of physical ring structures and ring redundancy protocols has been common for some time in the past. A challenge remains the configuration of such a redundancy protocol on each device with the networks stretching out over large areas, like in offshore wind power stations, where each windmill houses at least one Ethernet switch. The distance between windmills can be several kilometers and configuration of the redundancy protocol on each device is an elaborate process. In this paper, a mechanism is proposed which automatizes the configuration of ring redundancy protocols and eliminates the need to configure each device separately. The actual protocol implementation is intended to be part of the next major software release of Hirschmann Industrial Ethernet Switches.

Industrial networks used to control production machinery require high availability to keep possible productivity losses to a minimum. The challenges to overcome are how we are to acquire the needed device information - also with a possible network error already in place - and how to process and pass on this information in order for errors to be quickly fixed. We took possible error scenarios and the data available on the devices to determine which errors can be detected and processed and propose a system of abstraction which provides administrative and service personnel with means to quickly and efficiently identify and fix detected errors.

The use of Ethernet based solutions in automation applications raises the question of test tools. Free tools like Wireshark, formerly known as Ethereal, are available and offer decoding of real-time Ethernet like PROFINET IO. But is such a software based tool able to measure the required real-time constraints? What are the limits of such software based measurements? This report gives an overview of possible measurement setups and a choice of measured benchmarks.

PROFINET, an automation network based on Ethernet, includes the automatic discovery of the physical topology with the link layer discovery protocol (LLDP) in its newest specifications. In this paper we present the objectives of LLDP in PROFINET and general information about the protocol and other parts of IEEE 802.1AB, which describes LLDP. During the analysis of different implementations on the market, we found several problems of LLDP as well as issues with the interaction to a network management system. These are described in the later chapters.

A Profinet IO network of class A uses standard Ethernet network components. If these network components can be attacked by e.g. a man-in-the-middle attack, this is also the case for Profinet 10. This paper outlines these possibilities and shows, how this may be used to build IO-device emulators for system-testing.

After more than ten years of experience with applications of fieldbus in automation technology, the industry has started to develop and adopt Real-Time Ethernet (RTE) solutions. There already exists now more than ten proposed solutions. International Electrotechnical Commission standards are trying to give a guideline and selection criteria based on recognized indicators for the user.

The paper gives an overview of the communication architectures adopted in the industrial automation for the electrical drives, ensuring a fast data exchange and high performance control. An attempt is made at defining real-time operation for this application field, at reviewing the standardization work done to unify the electrical drive interfaces, and at encompassing the recently accepted solutions, including those based on the industrial Ethernet.

For more than a decade the experts have tried to convince the users, that Ethernet is not suitable for applications in real-time communication. Only fieldbus are well adapted to the real-time problems in the automation applications. Today several manufactures propose networking solutions based on the Ethernet-TCP/IP networks. The paper presents examples of problems to be solved, when a user intends to replace fieldbus networks by Ethernet-TCP/IP based networks for automation applications.