LLM-based Iterative Requirements Refinement in FSM with IEC 61499 Code Generation

This paper presents the Function Block Assistant (fbAssistant), an LLM-backed tool prototype for developing control logic in industrial automation. fbAssistant interprets natural language requirements and automatically generates state machines and their function blocks implementation. The study demonstrates iterative refinement, simulation validation, and deployment using EcoStruxure Automation Expert. The proposed approach aims at improved efficiency and accuracy in the development of automation software.