Industrial communication networks – Fieldbus specifications – Part 4-12: Data-link layer protocol specification – Type 12 elements
|Publication Date:||1 August 2014|
|ICS Code (Networking):||35.110|
|ICS Code (Data link layer):||35.100.20|
|ICS Code (Industrial process measurement and control):||25.040.40|
The data-link layer provides basic time-critical messaging communications between devices in an automation environment.
This protocol provides communication opportunities to all participating data-link entities
a) in a synchronously-starti
b) in a cyclic or acyclic asynchronous manner, as requested each cycle by each of those data-link entities.
Thus this protocol can be characterized as one which provides cyclic and acyclic access asynchronously but with a synchronous restart of each cycle.
These procedures are applicable to instances of communication between systems which support time-critical communications services within the data-link layer of the OSI reference model, and which require the ability to interconnect in an open systems interconnection environment.