Maintaining HMI and SCADA Systems Through Computer Virtualization

This paper examines computer virtualization as a solution to issues encountered in maintaining HMI and SCADA systems based on commercial off-the-shelf computing hardware. Following a brief primer, this paper outlines issues arising from the rapid advancement of personal and server computing hardware, including automation software conflicts with new operating systems, device driver availability for old operating systems, and migrating backup images to new hardware. Opportunities for improvement are identified in backup and recovery, operator access to computing resources, and prototyping HMI and program changes. The concept of a virtual machine is introduced, and common architectures are examined, followed by the description of an example virtualized control room. Finally, this paper examines the experiences of a multisite cement producer in implementing virtualization in two of their plants. This examination explores the reasoning, advantages, disadvantages, and limitations encountered in moving existing systems to a virtualized platform.