STEP-NC and function blocks for interoperable manufacturing

Interoperable manufacturing systems help manufacturing companies stay competitive in the environment of frequent and unpredictable market changes. An important part of a manufacturing system is computer numerically controlled (CNC) machine tools. Over the years, G-codes have been extensively used by CNC machine tools and are now considered as a bottleneck for making these machines adaptable and interoperable. Two new technologies emerged in recent years: Standard for the Exchange of Product data for Numerical Control (STEP-NC) and function blocks. The STEP-NC data model represents a common standard for NC programming, making the goal of a generic NC code generation facility a reality. Function blocks are an emerging IEC standard for distributed industrial processes and control systems. They can be used for CNC controls to encapsulate machining data, such as machining features and their needed algorithms. This paper introduces the above two new standards and the technologies that are developed based on the standards. The main body is devoted to analyze the standards from the functionality viewpoint. These functionalities include, bidirectional information flow in computer-aided design/computer-aided manufacturing, data sharing over the Internet, the use of feature-based machining concept, modularity and reusability, intelligent and autonomous CNC, and portability among resources. Some implementations are also presented to showcase how the standards are used to develop technologies for interoperable machining.