scope:

The Data-Link layer provides basic messaging communications between devices in an automation environment. The protocol and services provide a communication for WirelessHART1 based on a Physical layer according to IEEE 802.15.4. This PAS specifies a) the procedures for the transfer of data and control information from one Data-Link user entity to another user entity or many, and among the Data-Link entities forming the distributed datalink service provider; b) the structure of the fieldbus DLPDUs used for the transfer of data and control information by the protocol of this publication, and their representation as physical interface data units. The procedures are defined in terms of a) the interactions between DL-entities (DLEs) through the exchange of fieldbus DLPDUs; b) the interactions between a DL-service (DLS) provider and a DLS-user in the same system through the exchange of DLS primitives; c) the interactions between a DLS-provider and a Ph-service provider in the same system through the exchange of Ph-service primitives. These procedures are applicable to instances of communication between systems which support communications services within the Data-Link layer of the OSI or fieldbus reference models, and which require the ability to interconnect in an open systems interconnection environment. Profiles provide a simple multi-attribute means of summarizing an implementation's capabilities, and thus its applicability to various communications needs. This PAS also specifies conformance requirements for systems implementing these procedures. This standard does not contain tests to demonstrate compliance with such requirements.