Lines, Units, Cells
Lower-level elements that perform manufacturing, field device control, or vehicle functions.
- NOTE: Entities at this level may be connected together by an area control network and may contain information systems related to the operations performed in that entity.
Source: ANSI/ISA–99.00.01–2007, Security for Industrial Automation and Control Systems, Part 1: Terminology, Concepts, and Models, 29 October 2007. National Standard