This paper identifies and describes the numerical control (N/C) standards published by the Electronic Industries Association as EIA or ANSI/EIA standard in the United States and the N/C standards published by the International Organization for Standardization (ISO). The current status of projects and proposals for new N/C standards in both organizations is described, with emphasis on interfaces and communications links related to automated manufacturing. The object of these standards is the establishment of codes, formats, interfaces, protocols, and procedures to facilitate the automation of industrial machines and systems, including machine tools.