The data-link layer provides basic time-critical messaging communications between devices in an automation environment.

This protocol provides communication opportunities to a pre-selected ?master? subset of datalink entities in a cyclic asynchronous manner, sequentially to each of those data-link entities. Other data-link entities communicate only as permitted and delegated by those master data-link entities.

For a given master, its communications with other data-link entities can be cyclic, or acyclic with prioritized access, or a combination of the two.

This protocol provides a means of sharing the available communication resources in a fair manner. There are provisions for time synchronization and for isochronous operation.

Cross References:
IEC 61158-3-3:2014
IEC 61158-2:2014
ISO/IEC 7498?3
ISO/IEC 2022
ISO/IEC 7498-3
ISO/IEC 7498-1
ISO/IEC 7498?1
IEC 61131-3
ISO/IEC 10731
ISO/IEC 646
ISO 1177
ISO/IEC 8802 (all parts)
IEC 61158-1
IEC 60870-5-1
IEC 61158-6-3
IEC 61158-5-3
IEC 61784-1
ISO/IEC 3309
IEC 61784-2


Replaces BS EN 61158-4-3:2014 which remains current

All current amendments available at time of purchase are included with the purchase of this document.