The integration of diverse data sources into Asset Administration Shell (AAS) is a cornerstone for the advancement of digital twin technologies in industrial ecosystems. To ensure proper data integration, a concept should meet the requirements related to data integration as well as those related to AAS. This study compares three key data integration concepts for AAS-BaSyx Python SDK, BaSyx DataBridge, and the standardized descriptive approach through Asset Interfaces Description (AID) & Asset Interfaces Mapping Configuration (AIMC) submodels. To evaluate the advantages and limitations of each concept, this study employs 12 distinct criteria, assessing how effectively each concept aligns with these criteria. The result provides insights into the unique features of each concept, informing stakeholders about optimal strategies. This study suggests a synergistic approach that combines the advantages of the various methodologies, thereby overcoming individual limitations and enhancing the digital twin ecosystems.

The Internet of Things (IoT) enables connectivity between devices, thereby allowing them to interact with each other. A recurring problem is the emergence of siloed IoT platforms due to proprietary standards. Recently, the World Wide Web Consortium (W3C) proposed a human-readable and machine- understandable format called Thing Description (TD). It allows to uniformly describe device and service interfaces of different IoT standards with syntactic and semantic information, and hence enables semantic interoperability. However, describing sequential behavior of devices, which is essential for many cyber-physical systems, is not covered. In this paper, we propose a systematic way to describe such sequential behavior as an extension within TDs, thereby increasing their semantic expressiveness through possible, valid state transitions. This enables safe and desired operation of devices as well as scalability by modeling systems as sequential compositions of Things. We show in a case study that previously unmodelable behavior can now be expressed and the overall manual intervention requirements of state-of-the-art implementations can be significantly reduced.

Embedded network programming remains a highly complex task for developers since unique characteristics of such networks have to be faced: one of them is the communication between a diversity of resource constraint nodes. Another one is the infrastructure dynamics. The widely-used standardized Web service technologies would perfectly meet such unique characteristics and ease the development of applications. Such technologies that enable, e.g., requesting or subscribing service data, however, process usually plain XML documents which are not suitable for small embedded devices with very limited resources. This is due to XML's verbosity, its bandwidth usage, and its associated processing overhead. The paper addresses these issues and describes an innovative and optimized source code generation technique by means of W3C's Efficient XML Interchange (EXI) format for developing XML-based Web services for the embedded domain. This offers developers a seamless use of the wide-spread service protocols in the embedded domain as well. Evaluation results based on the dataset from the ISO/IEC standardization of the vehicle to grid communication interface (V2G CI) prove the applicability of the generated XML-based Web services of restricted devices in terms of message size, performance, and code footprint.