OT Data Models are the initial point of data generation, and they come in two forms: Specific Operational Models, and Generalized abstracted Data Models.
Specific Operational Models
Specific Operational Models provide a general understanding of how the process works, and define tags and their possible values. These models are designed to explain how a particular machine or process operates in a manufacturing environment. Here are some examples:
- Weihenstephan Standards (WS) 09.01: These standards form a universal communication interface for linking machines to higher-level data collection systems like Manufacturing Execution Systems (MES). WS standards cater to different subdomains and are currently being integrated into an OPC UA information model by the OPC Foundation.
- Omron PackML: PackML or Packaging Machine Language standardizes the programming of automated machines, including machine states and modes of operation. It also standardizes terminology and predictability in multi-programmer machine design environments.
- EUROMAP 84: This is an OPC UA information model for extrusion that includes a comprehensive line and various components. This series, provided by EUROMAP, facilitates data exchange between an extrusion line's components and a Manufacturing Execution System (MES).
- OPC 30060: This document outlines information-modelling concepts for a complete production workcentre or line. It is designed to enhance data exchange and interoperability among cigarette manufacturers and Original Equipment Manufacturers (OEMs), based on the OPC UA standard.
- VDMA 40502: Created by the OPC Foundation and VDW, this specification establishes an OPC UA Information Model for interfacing and exchanging data with Computerized Numerical Control (CNC) systems. It defines data items and their composition, providing a structured CNC data interface.
Generalized Abstracted Data Models
In contrast, generalized abstracted data models offer a holistic overview of the entire production process, but often stay on a general view and need to be combined with above mentioned specific operaitonal models. Some of these models include:
- OPC-UA: OPC Unified Architecture (OPC UA) is an open-source, cross-platform standard for data exchange from sensors to cloud applications, developed by the OPC Foundation. It has standardized data models available for more than 60 types of industrial equipment.
- Asset Administration Shells (AAS): An AAS is a digital representation of an asset containing all necessary information for its functionality and the functionality of associated assets. AAS can have multiple submodels depending on the asset's complexity, all of which are stored in a manifest acting as a directory.
Existing relational databases in operational technology can also act as sources for an event-driven architecture or Unified Namespace (UNS) model, a topic that will be expanded upon in subsequent chapters.