PLC Integrator: A modern tool for PLC-EPICS integration at ESS

PLC Integrator is a newly developed tool to integrate PLC based control systems with the EPICS (Experimental Physics and Industrial Control System) framework, replacing the legacy PLC Factory at the European Spallation Source (ESS). PLC Factory depended on the ESS Controls Configuration Database (CCDB) service and REST APIs to generate PLC code and interface via Modbus TCP/IP, but its outdated Python base and the scheduled decommissioning of CCDB made its continued support unsustainable. PLC Integrator reproduces all of PLC Factory's functionality while removing obsolete dependencies, and brings native support for modern protocols such as OPC UA and Beckhoff ADS, which are critical for upcoming integration efforts like Target Remote Handling systems and Neutron Scattering Systems. Designed for sustainability, extensibility and ease of maintenance, the tool enables automation engineers to rapidly implement new features as requirements evolve. This paper describes the design motivations, implementation strategies and integration outcomes of PLC Integrator, demonstrating how it modernizes control workflows at ESS, reduces technical debt, and enhances EPICS interoperability.