标准摘要
Provides basic time-critical messaging communications between devices in an automation environment. Specifies: a) procedures for a single protocol for the timely transfer of data and control information; b) the structure of the Fieldbus Data Link (DL) Protocol Data Units. Provides communication opportunities to all participating data-link entities in a cyclic asynchronous and in a synchronous manner.
英文名称Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 4: Data Link protocol specification