Supervision and monitoring

Explain in your own words what a SCADA system does and what the words in its acronym stand for (supervisory control and data acquisition). Give an example of a facility where it is essential.

Explain what telemetry is (measuring remotely and sending data) and describe an everyday or familiar example where measurements sent automatically over a network are used, indicating what is measured and who receives the data.

The mimic screen represents the plant schematically with live values. Explain the advantages of viewing the plant in this way, rather than looking only at data tables (locating each value on its machine, detecting anomalies at a glance).

A remote setpoint allows changing a reference value from the control room. Give an example (changing the temperature of a climate-controlled hall from the central control) and describe the path this command takes to the actuator.

SCADA stores historical data for all variables. Explain the purpose of checking data from months ago (finding when a fault started, planning maintenance before a failure) using a concrete example.

Distinguish between monitoring a process (observing and recording it) and controlling it (acting upon it). Explain why a SCADA system typically does both and give an example of a supervisory action and a control action in a city's water supply system.

Explain what an alarm is in a SCADA system, what two states it can have (active, acknowledged), and why acknowledging an alarm is not the same as resolving it.

When an alarm is triggered, the system requires the operator to acknowledge it. Explain what is recorded with this acknowledgement (who saw it and when), why it is important for accountability, and what risk is posed by the habit of acknowledging alarms without looking at them.

During the commissioning of a chemical reactor, 140 alarms are recorded on the SCADA console in just two minutes. Hidden within the continuous list of pop-up events is a critical warning of a pressure drop in the cooling circuit that the operator overlooks while trying to silence the acoustic alerts, causing an overtemperature trip.

1. a) Diagnose the design problem that causes this "alarm flood" and justify why treating any sensor state change as an alarm undermines the operator's supervisory role.
2. b) Design a technical solution for the SCADA system based on three mechanisms: dynamic alarm suppression according to the operating phase, hierarchical prioritisation, and deadband or hysteresis filtering. Explain how each of these mechanisms would act during a start-up transient to prevent operator overload.

A company supervises 50 remote stations from a single control centre. Analyse what changes compared to supervising a single local plant (reliance on communications, prioritization of alarms arriving from multiple sites, minimum duty staff) and what minimum redundancy you would require for the communications network.

A group of cyberattackers manages to infiltrate the corporate network of an electricity distribution company and attempts to manipulate substations through a data spoofing attack targeted at the SCADA system. The goal is to inject false voltage and temperature values into the HMI interface to deceive operators while physically overloading the transformers.

1. a) Predict the technical and operational impact of this attack on grid stability if operators make decisions based on falsified readings before local electromechanical protections trip.
2. b) Design an industrial cybersecurity architecture proposal based on the ISA/IEC 62443 standard: justify the separation between IT and OT networks using zones, conduits, and an industrial DMZ, and explain what role a data diode or unidirectional gateway plays in protecting infrastructure supervision.

A security audit at a drinking water treatment plant detects that the PLCs controlling chlorine dosing and discharge pumps are on the same IP subnet as the administration computers, and that the manufacturer has permanent remote access without two-factor authentication to apply live software patches.

1. a) Analyze the attack vectors opened by this configuration: predict what could happen if an office computer is infected with malware or if an attacker exploits remote access to modify the disinfection setpoints in the PLCs.
2. b) Justify why in industrial automation environments (OT networks) the deployment of patches and updates cannot be automated as in office computers (IT networks), analyzing the concepts of uninterrupted availability, real-time determinism, and the need for prior validation on test benches or digital twins.