11 research outputs found
Contribution to IO-Link wireless safety – architecture and system extensions
No full textFunctional safety systems protect humans and equipment from hazards while machines or humans perform automation processes. Therefore, the systematic and safe design of functional safety protocols and systems together with appropriate safety management and maintenance concepts is critical and must follow quality standards.
In the field of production automation, IO-Link Wireless (IOLW) offers energy-efficient and cost-effective solutions for wireless sensors/actuator communication close to the machines on the industrial shop-floor. In case of safety applications within IO-Link (IOL), currently only a wired extension of a functional safety protocol, called IO-Link Safety (IOLS), exists. Thus, the applied safety features in IOLS are not sufficient for a safety extension of IOLW. Therefore, a safety concept proposal to enhance IOLW with safety features is suggested. This proposal is realized for safety critical communication in industrial environments with performance characteristics of demanding safety integrity level (SIL) 3 requirements.
As also data security is of paramount importance, security-for-safety mechanisms are adopted for IOLW Safety, especially to meet the necessary criteria within the safety requirement specification (SRS) to ensure a one-to-one connection between an IOLW Master and an IOLW Device. Potential cryptographic algorithms are evaluated with respect to energy consumption and timing. Reliable and energy-efficient characteristics are crucial for a fast and secure wireless communication solution, especially for mobile safety applications. Therefore, the current consumption should not significantly increase due to implemented cryptographic algorithms. A current measurement method is designed to evaluate the current consumption for different crypto-algorithms together with an uncertainty estimation.
Furthermore, a SRS is elaborated together with an authorized certification organization with a profound focus on standards (mainly IEC 61508 and IEC 61784-3) regulating the probability of dangerous failure on demand (PFD) addressed within SRSs. Also, relevant security standards (e.g., IEC 62443) involving security-for-safety for IO-Link Wireless Safety (IOLWS) are considered. The PFD is determined using probabilistic models to verify the regulations stated in the standards. Taking performance parameters into account, which are crucial for industrial manufacturing processes, a safety process data unit (SPDU) is designed and certified by the authorized safety organization for different payload lengths and cycle times. This is necessary, because for various applications safety devices require different payload lengths. Therefore, measurements for different payload lengths to enable various safety devices are performed to analyze cycle and processing times of the communication channels and devices.
The protocol architecture, including a safety and security communication layer, is introduced including services to provide features to the application layer. A prototype implementation assures that the concept is applicable in real world with existing hardware to meet the stated requirements within the SRS. The measurements demonstrate feasibility of the concept and its assumptions.Funktionale Sicherheitsprotokolle schützen Menschen und Geräte vor Gefahren, während diese in automatisierten Produktionsprozessen tätig sind. Daher ist das systematische und sichere Design von Kommunikationsprotokollen und Systemen der funktionalen Sicherheit in Kombination mit geeigneten Management- und Wartungskonzepten von entscheidender Bedeutung und muss Qualitätsstandards folgen.
Im Bereich der Fertigungsautomatisierung und industriellen Automatisierung ermöglicht IO-Link Wireless (IOLW) energieeffiziente und kostengünstige Lösungen zur maschinennahen Vernetzung drahtloser Sensoren und Aktoren. Für Sicherheitsanwendungen innerhalb von IO-Link (IOL) existiert momentan ausschließlich eine drahtgebundene Erweiterung eines funktionalen Sicherheitsprotokolls, genannt IO-Link Safety (IOLS). Da die in IOLS verwendeten Sicherheitsmaßnahmen für eine Safety-Erweiterung von IOLW zu einem funktionalen Sicherheitsprotokoll nach SIL 3 nicht genügen, werden weitere Sicherheitsmaßnahmen vorgeschlagen.
Da auch die Cyber-Sicherheit von großer Bedeutung ist, werden Sicherheitsmechanismen, die bereits in anderen drahtlosen Protokollen implementiert sind, untersucht und Security-for-Safety-Mechanismen für IOLW ausgearbeitet und empfohlen, insbesondere um die erforderlichen Kriterien relevanter Normen (IEC 61508, IEC 61784-3, IEC 62443) zu erfüllen. Potenzielle kryptografische Algorithmen werden für IOLW im Hinblick auf Energieverbrauch und Timing evaluiert, um zuverlässige und energieeffiziente Eigenschaften für eine schnelle, sichere und batteriebetriebene drahtlose Kommunikationslösung zu gewährleisten. Eine Voraussetzung hierfür ist, dass der Stromverbrauch durch zusätzliche kryptografische Operationen nicht signifikant ansteigt. Zur Bewertung des Stromverbrauchs wird ein prinzipielles Strommessverfahren entwickelt und eine Unsicherheitsabschätzung (guide to the expression of uncertainty in measurement (GUM)) anhand statistischer Messdaten unter Berücksichtigung der kombinierten Standardunsicherheit durchgeführt.
Zum Schutz vor inakzeptablen Risiken, die z.B. bei Automatisierungssystemen durch Ausfälle entstehen können, wurde gemeinsam mit einer autorisierten Zertifizierungsorganisation eine Sicherheitsanforderungsspezifikation (safety requirement specification (SRS)) für IOLW Safety erarbeitet. Bei diesem Ansatz wurde ein starker Fokus auf internationale Standards gelegt, die die durchschnittliche Wahrscheinlichkeit eines gefährlichen Ausfalls bei Bedarf (probability of dangerous failure on demand (PFD)) regeln, die in SRSs und relevanten Sicherheitsnormen unter Berücksichtigung der funktionalen Sicherheit und Security-for-Safety-Betrachtungen für IOLWS behandelt werden. Die Ausfallwahrscheinlichkeit (PFD) wird mithilfe probabilistischer Modelle ermittelt, um die in den Normen festgelegten Vorschriften zu überprüfen. Unter Berücksichtigung von Leistungs- und Sicherheitsparametern, die für industrielle Automatisierungsprozesse von entscheidender Bedeutung sind, wird eine Sicherheitsprotokolldateneinheit (safety process data unit (SPDU)) für unterschiedliche Datenlängen und Zykluszeiten entwickelt und von einer autorisierten Sicherheitsorganisation zertifiziert. Messungen für verschiedene Datenlängen von Protokollapplikationsdaten zur Nutzung unterschiedlicher Sicherheitsgeräte werden durchgeführt und analysiert, um Zyklus- und Verarbeitungszeiten der Kommunikationskanäle und -geräte darzustellen.
Eine Protokollarchitektur mit einer Kommunikationsschicht für funktionale und cyber-Sicherheit wird eingeführt, die Dienste zur Bereitstellung von Funktionen für die Anwendungsschicht enthält. Dabei stellt eine Prototyp-Implementierung sicher, dass das Konzept in der realen Welt mit vorhandener Hardware anwendbar ist, um die Anforderungen an funktionaler und cyber-Sicherheit zu erfüllen. Die durchgeführten Messungen zeigen auch die Umsetzbarkeit des Konzepts und ggfs. entsprechende Akzeptanz.N
Precision measurement of the application-dependent current consumption of a wireless transceiver chip in the time and frequency domain
No full textModern production concepts generate a demand for reliable, energy-efficient, fast, and secure wireless communication solutions. Therefore, the current consumption should not increase substantially due to additional cryptographic operations. This paper shows a principle current measurement method that is exemplary of a transceiver for the IO-Link Wireless protocol. Low-pass filtering and single-sided amplitude spectrum analysis are used to evaluate the main information of the current measurement. An uncertainty estimation is realized using statistical measurement data and considering the measurement setup in order to approximate the combined standard uncertainty. The results show that the current consumption only increases slightly when using additional cryptographic operations. This can be measured with acceptable uncertainty.N
Safety Architecture Proposal for Low-Latency Sensor/Actuator Networks using IO-Link Wireless
No full textIn the field of production automation, IO-Link Wireless (IOLW) offers energy-efficient and cost-effective solutions for networking wireless sensors and actuators close to the machines on the industrial shop-floor. In this paper, a concept is presented to enhance IOLW with security-for-safety and safety features in order to make safety critical systems in industrial environments with performance characteristics dedicated to demanding applications feasible. As data security is of paramount importance, security mechanisms already implemented in other wireless protocols are investigated and security-for-safety mechanisms for IOLW are introduced. Potential cryptographic algorithms are evaluated for IOLW with respect to energy consumption and timing. Taking performance parameters into account, which are crucial for industrial manufacturing processes, a safety protocol data unit (SPDU) is described and evaluated for different payload length and cycle times. Finally, an outlook towards the implementation of a demonstrator setup completes this work.N
Study of a Safe and Secure Ecosystem based on IO-Link Wireless and a 5G Campus Network
No full textWireless networks support highly flexible manufacturing processes and are recognized as a crucial pillar towards the digitization of industrial production (automation). While 5G is currently being marketed as universal solution for future wireless communication, high density of sensor and actuator nodes in industrial manufacturing environments with respect to latency times and reliability, still represents an enormous technical challenge. In the field of production automation standards, IO-Link Wireless (IOLW) is already in operation offering energy-efficient and cost-effective solutions, even with battery-powered smart sensor devices. In this paper, the deterministic ultra-reliable low-latency communication (URLLC) features of 5G are combined with the outstanding performance characteristics of IOLW with respect to robustness and latency to realize even highly demanding safety applications in industrial environments.N
On the Security of IO-Link Wireless Communication in the Safety Domain
No full textSecurity is an essential requirement of Industrial Control System (ICS)
environments and its underlying communication infrastructure. Especially the
lowest communication level within Supervisory Control and Data Acquisition
(SCADA) systems - the field level - commonly lacks security measures. Since
emerging wireless technologies within field level expose the lowest
communication infrastructure towards potential attackers, additional security
measures above the prevalent concept of air-gapped communication must be
considered. Therefore, this work analyzes security aspects for the wireless
communication protocol IO-LinkWireless (IOLW), which is commonly used for
sensor and actuator field level communication. A possible architecture for an
IOLW safety layer has already been presented recently. In this paper, the
overall attack surface of IOLW within its typical environment is analyzed and
attack preconditions are investigated to assess the effectiveness of different
security measures. Additionally, enhanced security measures are evaluated for
the communication systems and the results are summarized. Also, interference of
security measures and functional safety principles within the communication are
investigated, which do not necessarily complement one another but may also have
contradictory requirements. This work is intended to discuss and propose
enhancements of the IOLW standard with additional security considerations in
future implementations.N
Testbed for functional safety-relevant wireless communication based on IO-Link Wireless and 5G
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Coexistence Management Methods and Tools for IO-Link Wireless
No full textWireless communication systems are enabler technologies for modern and flexible production concepts, essentially within the Industry 4.0 directive. For reliable low-latency wireless communication, the availability of frequency spectrum is a general prerequisite. IO-Link Wireless (IOLW) is a vendor-independent wireless communication standard, which operates in the 2.4 GHz ISM (Industrial, Scientific, Medical) band and especially addresses the requirements of industrial discrete manufacturing processes. The 2.4 GHz ISM band is used by various other radio systems, making coexistence management a fundamental challenge. Blacklisting and frequency hopping schemes are specified to increase the IOLWcoexistence behavior. In this paper coexistence management methods and tools, which can be employed for IOLW are presented. These tools can be used to enhance the coexistence behavior and thus the reliability, and at the same time, reduce energy consumption. After an introduction and a detailed presentation of IOLW, a software tool is presented that allows to implement an intelligent frequency management by adapting blacklists to the respective coexistence and boundary conditions. This is based on generic measurements, which are also shown in this paper. Finally, a conclusion and an outlook for further integration into an overall system are given.N
Testbed and Software Architecture for Enhancing Security in Industrial Private 5G Networks
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