Developing and Validating OPC-UA Based Industrial Controls for Power Supplies at CERN

The industrial control systems of CERN’s experiments are undergoing major renovation since 2017 and well into CERN’s second Long Shutdown (LS2) until the end of 2019. Each detector power-supply control system runs several hundred software instances consisting of many different components in parallel on a large scale, broadly distinguishable as servers and clients. Our accumulated experience during LHC runs proves that some complex control issues are impossible to detect using stand-alone components on a small scale only. Furthermore, new components must be developed well before the electron-ics becomes available, without impact on operations. Moreover, during LS2, the improved and now widely established Open Protocol Communication Unified Ar-chitecture (OPC-UA) replaces OPC-DA as middleware protocol. For these reasons, we developed a simulation environment to emulate the real, and valuable, CAEN power-supply electronics underneath the OPC-UA serv-ers. This distributed simulation is configurable to mimic and exceed the nominal conditions during production and provides a repeatable setup for validation. This paper discusses the functionality and use of this simulation service.