Sanjay Ghosh, ABB Corporate Research, Bangalore
Pradyumna Sampath, ABB Corporate Research, Bangalore

Real time control applications in industrial control systems have long been trusted to run on specially designed dedicated embedded hardware like PLCs, controllers etc. The non real-time functionalities of the automation systems like engineering and HMI are separately executed on independent hardware. Over the last decade, advancements in RTOS, technologies such as virtualization and availability of more powerful COTS hardware have enabled the recent trends where industrial PCs are being proposed to replace the hardware controller units. This paper describes our prototype implementation of a control system on a general purpose embedded hardware based on Linux rt-preempt. In our setup, the control logic is executed by a runtime control engine in a virtual machine environment alongside the standard engineering framework, standard HMI, data acquisition, EtherCAT based IO and fieldbus modules on a uni-processor system without impacting the deterministic performance. The paper discusses in detail the methodologies used, our experiences and the lessons learnt in evaluating the performance of the prototype in terms of the test setup, boundary conditions and the parameters measured under typical load conditions as in real industrial applications.