Showing papers by "Jurgen Jasperneite published in 2011"

An isochronous medium access for real-time wireless communications in industrial automation systems - A use case for wireless clock synchronization

Abstract: Wireless technologies are increasingly deployed in factory automation systems, because they are able to provide several advantages, e. g., a higher level of mobility, more flexibility, and at the same time causing lower costs. However, the requirements of industrial applications in terms of real-time communication can not be satisfied by existing wireless technologies, such as IEEE 802.11Wireless Local Area Networks (WLANs). This is due to their unpredictable behaviour and the introduction of delays beyond acceptable bounds, mainly caused by a non-deterministic medium access. Hence, the proposed wireless communication system provides real-time communication services based on the IEEE 802.11 protocol family. In this paper we present a new isochronous medium access control mechanism, called IsoMAC. The paper addresses IsoMAC and shows how, in combination with a suitable wireless clock synchronization, IsoMAC is able to satisfy the typical constraints of soft real-time flows found on the factory floor. A simulation case study is provided that shows the achievable update times of the proposed combination.

A proposal to integrate process data communication to IEEE 802.1 Audio Video Bridging (AVB)

Abstract: This paper investigates prospects of the emerging IEEE 802.1 Audio Video Bridging (AVB) Ethernet standard in industrial automation applications. The notion of a small and predictable latency is common for both industrial and multimedia (audio, video) applications. The inbuilt characteristics of 802.1 AVB that includes synchronization, real-time traffic scheduling & shaping and resource reservation makes it a real-time capable Ethernet solution, which can be used for the process control applications as well. This paper presents a way to integrate the industrial process data communication to the lower layer services of IEEE 802.1 AVB, and describes a demonstrator implemented for a proof of concept.

Interoperabilität auf Feldebene

Abstract: Zusammenfassung Die Feldebene ist die dem technischen Prozess am nächsten gelegene Ebene der Automatisierungspyramide. Bedingt durch Fortschritte in der Mikroelektronik und der Informations- und Kommunikationstechnologien werden die vernetzten Feldgeräte immer “intelligenter” und übernehmen zunehmend auch Automatisierungsfunktionen, die bisher anderen Ebenen zugeordnet waren. In dem Beitrag werden die beiden Interoperabilitätsaspekte Kommunikation und Anwendung von Feldgeräten betrachtet. Abstract The Field level is the level within the Automation pyramid, which is closest to the Process. Due to advances in the field of Micro Electronics and within Information and Communication technologies, field devices become more “Intelligent” and fulfil automation functions, which have been allocated at other levels of said pyramid. Within this paper both key aspects of interoperability of field devices are considered — Communication and Application.

mINA-DL: A novel description language enabling dynamic reconfiguration in industrial automation

Abstract: Production facilities have to cope with fast changing market demands-leading to a need for high adaptability of the manufacturing plant. Especially the manual adaption of the automation systems causes high costs and significant downtimes. Here, an approach for an automatic adaption of the automation system is presented. The major challenges for an automatic adaptability of the automation system are (i) dynamically modifiable networks, (ii) a real-time middleware transporting variables within the network independently of the automation topology, and (iii) a semantic-based mechanism that allows one plant module to identify which signals are needed from another module. This paper describes a real-time middleware for industrial automation (mINA). It focuses especially on problem (iii), the mechanism to discover and identify required process signals. The functionality is based on a newly defined description language (mINA-DL), i.e. the middleware can use further semantic information about the signals. The middleware (ii) communicates by means of a real-time publish/subscribe concept and provides OPC UA compliance which also allows an easy integration with the manufacturing execution system (MES). Furthermore, a first prototypical implementation of the middleware is described and assessed using a test environment.

Wireless local area networks and its impact on current and future production processes

Abstract: Received: 10 January 2011 Abstract Accepted: 7 February 2011 Nowadays there is a high demand to produce more, for a lower price and at the same time offer diversity of products. To achieve these aims, production lines need to be more flexible. The current network communications systems are dominated by the Ethernet technology and dedicated industrial protocols. Ethernet based industrial protocols have many advantages like: full duplex communication without collisions, high bandwidth or high communication reliability. However, they have one big disadvantage, limited mobility. Since a network device needs to be connected using cable, its placement is rather fixed. Apart from that, costs related with wired network infrastructure or further extensions are expensive and frequently complicated. Due to these reasons, the industrial users are looking towards wireless communication. A prominent candidate is the IEEE 802.11 WLAN standard, as it has comparable with the Ethernet data rates and resembles data link layer. An overview of how the WLAN standard fits to the industrial environment and a discussion about the current usage of the WLAN in industrial environments as well as outlook for future deployments will be given.

Interoperabilität auf Feldebene Interoperability at Field Level

Abstract: Zusammenfassung Die Feldebene ist die dem technischen Prozess am nachsten gelegene Ebene der Automatisierungspyramide. Bedingt durch Fortschritte in der Mikroelektronik und der Informations- und Kommunikationstechnologien werden die vernetzten Feldgerate immer „intelligenter“ und ubernehmen zunehmend auch Automatisierungsfunktionen, die bisher anderen Ebenen zugeordnet waren. In dem Beitrag werden die beiden Interoperabilitatsaspekte Kommunikation und Anwendung von Feldgeraten betrachtet. Summary The Field level is the level within the Automation pyramid, which is closest to the Process. Due to advances in the field of Micro Electronics and within Information and Communication technologies, field devices become more “Intelligent” and fulfil automation functions, which have been allocated at other levels of said pyramid. Within this paper both key aspects of interoperability of field devices are considered – Communication and Application. Schlagworter Feldebene, Feldgerate, Interoperabilitat, Konformitat, Kommunikation Keywords Field level, field devices, interoperability, conformity, communication