Critical Infrastructure 2,, 2013 Slide 1

Critical infrastructure:

Infrastructure Control

Critical Infrastructure 2,, 2013 Slide 2

Infrastructure classes

• Physical infrastructure– Physical facilities and assets such as

pumping stations, pipelines, railways, roads, etc.

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Infrastructure classes

• Digital infrastructure– Networks, software and physical

facilities required for their operation, such as data centres

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Infrastructure classes

• Organisational infrastructure– Organisations that provide emergency

services, medical services, government and financial services

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Control Systems

• IT is used for monitoring and controlling infrastructure in almost all industries in the developed world

– Oil and Gas, Power Generation, Railways and Transmission, Water Management, Manufacturing, Production Plants

Critical Infrastructure 2,, 2013 Slide 6

© Alan Murray-Rust 2012

Critical Infrastructure 2,, 2013 Slide 7© Remi Kaupp 2006

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Image credit: http://media.boingboing.net/wp-content/uploads/2012/08/ERCOT-CONTROL-ROOM-2.jpg

System control centre monitors infrastructure state, reports problems and issues control commands

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Infrastructure control

• Infrastructure equipment is usually controlled using special-purpose hardware and software

• PLCs (Programmable Logic Controllers) are associated with specific components such as valves and switches

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Programmable Logic Controllers

• Stand-alone units which are associated with a controlled element or a group of controlled elements

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Programmable Logic Controllers

• PLCs usually have associated sensors that determine the state of the controlled element (so can detect whether a valve is open or closed) as well as sensors that sense whatever is being controlled (e.g. liquid flow)

Critical Infrastructure 2,, 2013 Slide 12

Programmable Logic Controllers

• PLCs send signals to actuators associated with the controlled element e.g. to motors that can open or close a valve

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Infrastructure control elements

PLC PLC

To SCADA system

Water pipelineMotorised

valveMotorised

valveFlow

sensor

Critical Infrastructure 2,, 2013 Slide 14

PLCs

• PLCs are often programmed using a simple graphical programming language called Ladder Logic

• They are hardened – designed for use in hostile environments (heat, vibration, dampness, etc.) and with low power requirements

Critical Infrastructure 2,, 2013 Slide 15© Bernd Stolte 2010

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Remote Terminal Units

• When sensing is required, so-called Remote Terminal Units (RTUs) may be used which collect sensor data and relay it to the central control system

Critical Infrastructure 2,, 2013 Slide 17

SCADA• PLCs can act autonomously – e.g. to

shut down an element but, more often are networked to a central control system that manages and controls all of the PLCs in the system.

• The central system is usually called a SCADA (Supervisory Control and Data Acquisition) system.