1.1 General
The fieldbus Application Layer (FAL) 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 3 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.
1.2 Specifications
The principal objective of this standard is to specify the syntax and behavior of the application
layer protocol that conveys the application layer services defined in IEC 61158-5-3.
A secondary objective is to provide migration paths from previously-existing industrial
communications protocols. It is this latter objective which gives rise to the diversity of protocols
standardized in parts of the IEC 61158-6 series.
1.3 Conformance
This standard does not specify individual implementations or products, nor does it constrain the
implementations of application layer entities within industrial automation systems.
There is no conformance of equipment to the application layer service definition standard.
Instead, conformance is achieved through implementation of this application layer protocol specification.
IEC 61158-6-3:2007 history
2019IEC 61158-6-3:2019 Industrial communication networks - Fieldbus specifications - Part 6-3: Application layer protocol specification – Type 3 elements
2014IEC 61158-6-3:2014 Industrial communication networks - Fieldbus specifications - Part 6-3: Application layer protocol specification - Type 3 elements
2010IEC 61158-6-3:2010 Industrial communication networks - Fieldbus specifications - Part 6-3: Application layer protocol specification - Type 3 elements
2007IEC 61158-6-3:2007 Industrial communication networks - Fieldbus specifications - Part 6-3: Application layer protocol specification - Type 3 elements