IEC/PAS 61158-4-22:2009(E) provides basic time-critical messaging communications between devices in an automation environment. This protocol provides communication opportunities to all participating data-link entities in a synchronously-starting cyclic manner, according to a pre-established schedule, and in a cyclic or acyclic asynchronous manner, as requested each cycle by each of those data-link entities. It contains an additional profile - SNpTYPE - which may be integrated into a future new edition of the IEC 61158-4 series.
English