Episode 6 — Identify OT Device Roles: Sensors, Actuators, Controllers, PLCs, HMIs, and RTUs

 This episode builds a clean mental map of common OT device roles so you can identify what a device does, what it trusts, and what happens when it fails or is manipulated. You’ll define sensors and measurement as the “eyes and ears” of a process, actuators as the physical “hands,” and controllers as the decision layer that applies logic to drive outputs safely. We compare PLCs and RTUs in terms of environment, communications patterns, and typical use cases, then explain how HMIs fit as operator interfaces that can display, acknowledge, and sometimes command process changes. You’ll learn why device role matters for security controls, because availability, integrity, and deterministic behavior can be more critical than confidentiality in many control scenarios. The episode includes troubleshooting cues for exam questions, like recognizing whether a symptom suggests sensor drift, controller logic issues, comms loss, or an HMI display problem, and then choosing the safest next step. Produced by BareMetalCyber.com, where you’ll find more cyber audio courses, books, and information to strengthen your educational path. Also, if you want to stay up to date with the latest news, visit DailyCyber.News for a newsletter you can use, and a daily podcast you can commute with.