Specification Design and Scenario Implementation for MES-Equipment Interface Communication in Digital Factory Environments: A Case Study of Mitsubishi Q-Series PLC

In digital factory environments, one of the critical requirements for maximizing the effectiveness of production and quality management in advanced manufacturing plants is the establishment of real-time communication between the Manufacturing Execution System (MES) and both process equipment and logistics automation systems. While SEMI(GEM)-based HSMS specifications offer a well-structured framework—including defined Streams, Functions, and communication scenarios—making it relatively straightforward to develop standardized interface specifications, no equivalent standard exists for MES-PLC communications. In practice, interface specifications involving PLCs are often defined individually by users, depending on equipment characteristics, which leads to inconsistencies and hinders scalability. This study aims to formalize an interface specification between MES and process equipment in secondary battery manufacturing environments, using Mitsubishi’s Q-series PLCs. The proposed methodology provides a structured approach to designing interface specifications based on Bit/Word mapping and Excel-based documentation. The goal of this research is to support manufacturing sites that intend to implement MES-equipment interfaces by offering a practical, reusable, and scalable implementation guide that can be adapted to various equipment environments.