IEC 61158-6-12:2010

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.

L'IEC 61158-6-12:2014 décrit le protocole mis en place pour définir la représentation filaire des primitives de service définies dans la CEI 61158-5-12 et définir le comportement visible de l'extérieur associé à leur transfert. La présente norme spécifie le protocole de la couche application de bus de terrain de Type 12, en conformité avec le modèle de référence de base OSI (ISO/CEI 7498-1) et la structure de la couche application OSI (ISO/CEI 9545). Cette troisième édition annule et remplace la deuxième édition parue en 2010. Elle constitue une révision technique. Les principales modifications sont: - réparations des erreurs; - améliorations éditoriales; - prise en charge de l'Identification Explicite d'Appareils ajoutée en ESM.