257 research outputs found
Engineering PROFIBUS networks with heterogeneous transmission media
A significant number of process control and factory automation systems use PROFIBUS as the
underlying fieldbus communication network. The process of properly setting up a PROFIBUS
network is not a straightforward task. In fact, a number of network parameters must be set for
guaranteeing the required levels of timeliness and dependability. Engineering PROFIBUS
networks is even more subtle when the network includes various physical segments exhibiting
heterogeneous specifications, such as bus speed or frame formats, just to mention a few. In this
paper we provide underlying theory and a methodology to guarantee the proper operation of such
type of heterogeneous PROFIBUS networks. We additionally show how the methodology can be
applied to the practical case of PROFIBUS networks containing simultaneously DP (Decentralised
Periphery) and PA (Process Automation) segments, two of the most used commercial-off-the-shelf
(COTS) PROFIBUS solutions. The importance of the findings is however not limited to this case.
The proposed methodology can be generalised to cover other heterogeneous infrastructures.
Hybrid wired/wireless solutions are just an example for which an enormous eagerness exists
Real-time communications over wired/wireless PROFIBUS networks supporting inter-cell mobility
PROFIBUS is an international standard (IEC 61158, EN 50170) for factory-floor communications, with several thousands
of installations worldwide. Taking into account the increasing need for mobile devices in industrial environments,
one obvious solution is to extend traditional wired PROFIBUS networks with wireless capabilities. In this paper, we outline
the major aspects of a hybrid wired/wireless PROFIBUS-based architecture, where most of the design options were
made in order to guarantee the real-time behaviour of the overall network. We also introduce the timing unpredictability
problems resulting from the co-existence of heterogeneous physical media in the same network. However, the major focus
of this paper is on how to guarantee real-time communications in such a hybrid network, where nodes (and whole segments)
can move between different radio cells (inter-cell mobility). Assuming a simple mobility management mechanism
based on mobile nodes performing periodic radio channel assessment and switching, we propose a methodology to compute
values for specific parameters that enable an optimal (minimum) and bounded duration of the handoff procedure
Engineering hybrid wired/wireless fieldbus networks - a case study
Advances in networking and information technologies
are transforming factory-floor communication systems
into a mainstream activity within industrial automation.
It is now recognized that future industrial computer
systems will be intimately tied to real-time computing
and to communication technologies. For this vision to
succeed, complex heterogeneous factory-floor
communication networks (including mobile/wireless
components) need to function in a predictable, flawless,
efficient and interoperable way. In this paper we re-visit
the issue of supporting real-time communications in
hybrid wired/wireless fieldbus-based networks, bringing
into it some experimental results obtained in the
framework of the RFieldbus ISEP pilot
Timing analysis of an inter-cell mobility procedure for a wired/wireless PROFIBUS network
Recently, there have been a few research efforts towards extending the capabilities of fieldbus networks to encompass wireless support. In previous works we have proposed a hybrid wired/wireless PROFIBUS network solution where the interconnection between the heterogeneous communication media was accomplished through bridge-like interconnecting devices. The resulting networking architecture embraced a Multiple Logical Ring (MLR) approach, thus with multiple independent tokens, where the communication between different domains was supported by the Inter-Domain Protocol (IDP). The proposed architecture also supports mobility of stations between different wireless cells. To that hybrid wired/wireless networking architecture we have proposed a worst-case response timing analysis of the IDP, without considering inter-cell mobility (or handoff) of stations. In this paper, we advance that previous work by proposing a worst-case timing analysis of the mobility procedure
CSP channels for CAN-bus connected embedded control systems
Closed loop control system typically contains multitude of sensors and actuators operated simultaneously. So they are parallel and distributed in its essence. But when mapping this parallelism to software, lot of obstacles concerning multithreading communication and synchronization issues arise. To overcome this problem, the CT kernel/library based on CSP algebra has been developed. This project (TES.5410) is about developing communication extension to the CT library to make it applicable in distributed systems. Since the library is tailored for control systems, properties and requirements of control systems are taken into special consideration. Applicability of existing middleware solutions is examined. A comparison of applicable fieldbus protocols is done in order to determine most suitable ones and CAN fieldbus is chosen to be first fieldbus used. Brief overview of CSP and existing CSP based libraries is given. Middleware architecture is proposed along with few novel ideas
Industrial multimedia over factory-floor networks
In this paper we describe a real-time industrial communication network able to support both controlrelated
and multimedia traffic. The industrial communication network is based on the PROFIBUS
standard, with multimedia capabilities being provided by an adequate integration of TCP/IP protocols into
the PROFIBUS stack. From the operational point of view the integration of TCP/IP into PROFIBUS is by
itself a challenge, since the master-slave nature of the PROFIBUS MAC makes complex the
implementation of the symmetry inherent to IP communications. From the timeliness point of view the
challenge is two folded. On one hand the multimedia traffic should not interfere with the timing
requirements of the "native" control-related PROFIBUS traffic (typically hard real-time). On the other
hand multimedia traffic requires certain levels of quality-of-service to be attained. In this paper we
provide a methodology that enables fulfilling the timing requirements for both types of traffic in these
real-time industrial LAN. Moreover, we describe suitable algorithms for the scheduling support of
concurrent multimedia streams
Recent advances in industrial wireless sensor networks towards efficient management in IoT
With the accelerated development of Internet-of- Things (IoT), wireless sensor networks (WSN) are gaining importance in the continued advancement of information and communication technologies, and have been connected and integrated with Internet in vast industrial applications. However, given the fact that most wireless sensor devices are resource constrained and operate on batteries, the communication overhead and power consumption are therefore important issues for wireless sensor networks design. In order to efficiently manage these wireless sensor devices in a unified manner, the industrial authorities should be able to provide a network infrastructure supporting various WSN applications and services that facilitate the management of sensor-equipped real-world entities. This paper presents an overview of industrial ecosystem, technical architecture, industrial device management standards and our latest research activity in developing a WSN management system. The key approach to enable efficient and reliable management of WSN within such an infrastructure is a cross layer design of lightweight and cloud-based RESTful web service
Current challenges and future trends in the field of communication architectures for microgrids
[EN] The concept of microgrid has emerged as a feasible answer to cope with the increasing number of distributed renewable energy sources which are being introduced into the electrical grid. The microgrid communication network should guarantee a complete and bidirectional connectivity among the microgrid resources, a high reliability and a feasible interoperability. This is in a contrast to the current electrical grid structure which is characterized by the lack of connectivity, being a centralized-unidirectional system. In this paper a review of the microgrids information and communication technologies (ICT) is shown. In addition, a guideline for the transition from the current communication systems to the future generation of microgrid communications is provided. This paper contains a systematic review of the most suitable communication network topologies, technologies and protocols for smart microgrids. It is concluded that a new generation of peer-to-peer communication systems is required towards a dynamic smart microgrid. Potential future research about communications of the next microgrid generation is also identified.This work is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and the European Regional Development Fund (ERDF) under Grant ENE2015-64087-C2-2. This work is supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant BES-2013-064539.Marzal-Romeu, S.; Salas-Puente, RA.; González Medina, R.; Garcerá, G.; Figueres Amorós, E. (2018). Current challenges and future trends in the field of communication architectures for microgrids. Renewable and Sustainable Energy Reviews. 82(2):3610-3622. https://doi.org/10.1016/j.rser.2017.10.101S3610362282
A Comprehensive Survey on the Cyber-Security of Smart Grids: Cyber-Attacks, Detection, Countermeasure Techniques, and Future Directions
One of the significant challenges that smart grid networks face is
cyber-security. Several studies have been conducted to highlight those security
challenges. However, the majority of these surveys classify attacks based on
the security requirements, confidentiality, integrity, and availability,
without taking into consideration the accountability requirement. In addition,
some of these surveys focused on the Transmission Control Protocol/Internet
Protocol (TCP/IP) model, which does not differentiate between the application,
session, and presentation and the data link and physical layers of the Open
System Interconnection (OSI) model. In this survey paper, we provide a
classification of attacks based on the OSI model and discuss in more detail the
cyber-attacks that can target the different layers of smart grid networks
communication. We also propose new classifications for the detection and
countermeasure techniques and describe existing techniques under each category.
Finally, we discuss challenges and future research directions
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