Plant Intelligent Automation and Digital Transformation: Cyber Security, IIoT, AR, VR, Big Data & Plant Applications is an expansive four volume collection reviewing every major aspect of the intelligent automation and digital transformation of power, process and manufacturing plants, from the specific control and automation systems pertinent to various power process plants through manufacturing and factory automation systems. The fourth volume, Plant System Security and IIoT applications reviews the challenges of plant cybersecurity threats to newly digitized networks and their mitigation using IIoT security applications. In order to understand variations of controls in different plants, detailed discussions are presented on plant and industry types. Through appendices required additional details on various transmission media, SCADA/Telemetry, simulation, fault tolerance/fault tolerant network, electrical area classification, enclosure class and intrinsic safety have been included to make the entire volume consistent.