CEI EN 61158-6-21 : 2013

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms, definitions, symbols,
  abbreviations, and conventions
4 FAL syntax description
5 Transfer Syntax
6 FAL protocol state machines
7 AP context state machine
8 FAL service protocol machine
9 AR protocol machine
10 DLL mapping protocol machine
Annex ZA (normative) - Normative references
         to international publications with
         their corresponding European
         publications
Bibliography

Gives 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.