IEC 61158-6-19:2010

It provides user programs with a means to access the fieldbus communication environment. In this respect, the FAL can be viewed as a "window between corresponding application programs." This standard provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type 2 fieldbus. The term "time-critical" is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life. It includes the following significant changes from the previous edition deletion of the former Type 6 fieldbus for lack of market relevance; addition of new types of fieldbuses; partition of part 6 of the third edition into multiple parts numbered.

IEC 61158-6-19:2014 defines the protocol provided to define the FAL user at the boundary between the user and the Application Layer of the Fieldbus Reference Model, and Systems Management at the boundary between the Application Layer and Systems Management of the Fieldbus Reference Model. This standard specifies the structure and services of the IEC fieldbus Application Layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498) and the OSI Application Layer Structure (ISO/IEC 9545). This third edition cancels and replaces the second edition published in 2010 and constitutes a technical revision. The main changes are: - introducing connections based on a producer-consumer model; - introducing additional mechanisms to realize features such as timestamping and oversampling; - improving the hotplug and redundancy features; - improving the phase switching and the error handling; - editorial improvements.