IEC 61158-4-21 Ed. 3.0 b:2023
IEC 61158-4-21 Ed. 3.0 b:2023 Industrial communication networks - Fieldbus specifications - Part 4-21: Data-link layer protocol specification - Type 21 elements
standard by International Electrotechnical Commission , 03/01/2023





![IEEE 1212.1-1993 [ Withdrawn ]](/en-default-medium/IEEE-1212-1-1993-jp.jpg)