Practical Industrial Cybersecurity

Appendix DReview and Exam Question Answers

The following are the answers to the questions presented in the reviews and exams for each chapter.

Chapter 1: Industrial Control Systems

Review Question Answers

1. To cause the PV to remain at some specific, predetermined value referred to as the set point (sp). The set point may be a fixed reference, such as a simple liquid level sensor mounted on a post, or it can be an adjustable reference like a common thermostat where the user can set a desired temperature to be maintained. For more information, see the section “Basic Process Control Systems.”
2. Remote Telemetry Units (RTUs). For more information, see the section “Remote Telemetry Units.”
3. Controller. For more information, see the section “Basic Process Control Systems.”
4. Programmable logic controller or PLC. PLCs are intelligent digital computing devices that are designed specifically to perform industrial control functions. For more information, see the section “Programmable Logic Controllers.”
5. Unlike IT computers, industrial process controllers are not designed to store data and process it later. Instead, they produce output conditions based on the current states of their inputs according to their internal configuration or programming. For more information, see the section “Industrial Process Controllers.”
6. A distributed control system (DCS). When processes become too complex for a single controller, or its components are geographically separated, it becomes necessary to distribute ...