Fieldbus device description using tag-based trees

Abstract

Fieldbus systems a r e generally static configured systems. However, the configuration processes are often complex and would take advantages of technologies providing flexibility, adaptability, etc. Specifically, fieldbus technologies are often incompatible to each other. A technology bringing on the one hand a homogeneous interface between different fieldbusses and, on the other hand providing a simple addressing mechanism and plug-and-piay capability could bring advantages to fieldbus systems. Therefore, a n alternative data format offering the aforementioned features is presented in this paper. This data format, called tag-based trees, is strongly related to XML and XML DOM trees, and basically provides a generic data format, which is suitable for almost all types of data. Moreover, it also gives the opportunity for fieldbus networks to provide semantics to the system by enriching the data with an appropriate structure describing the meaning of the data. Hence, it is also possible to provide a kind of interpretation instructions to the data consumer.

Towards Plug and Play in Home and Building Automation Networks

“…The semantic models supporting self description and binding, their flexibility and scalability will be of particular interest. In this context, the work of [13] and [14] shall also be taken into account.…”

Plug and participate for limited devices in the field of industrial automation

“…If all these aspects are summarized, an innovative plug-and-participate as well as communication mechanism results, which is further described in [24]. This specific topic is presented there with respect to fieldbus device descriptions based on tag-based trees.…”

“…Further information on the basic facilities such as data structures used and the matching algorithm itself are published in [24] and [27].…”

“…Such descriptions are the basis for the matching as already shown in the algorithm given in section 5.3.3.3.7. For example, generic tag-based tree structures can be used as description facility for the semantic fieldbus approach, which allow very efficient and flexible matching algorithms (see also the XMLObject hierachy in section 5.3.3.3.7, and [24]). The general mechanisms of the concept are rather simple -entities announce their facilities using such tag-based tree structures; e.g., a sensor uses a dedicated structure for its data and simply starts to broadcast appropriately structured messages to the community.…”

“…These attributes are extracted from the CD and are furthermore extended by additional information. Moreover, in order to avoid class loading, to ensure a generic data structure and finally to alleviate the obligatory matching, these attributes are stored in special objects in a dedicated XML format -they are called tag-based trees and are implemented in specific Java XMLObject instances (tag-based trees are described in [24]). …”