Discusses the fundamental control elements for critical national infrastructure

1. Critical Infrastructure 2,, 2013 Slide 1
Critical infrastructure:
Infrastructure Control

2. Critical Infrastructure 2,, 2013 Slide 2
Infrastructure classes
• Physical infrastructure
– Physical facilities and assets such as
pumping stations, pipelines, railways,
roads, etc.

3. Critical Infrastructure 2,, 2013 Slide 3
Infrastructure classes
• Digital infrastructure
– Networks, software and physical facilities
required for their operation, such as data
centres

4. Critical Infrastructure 2,, 2013 Slide 4
Infrastructure classes
• Organisational infrastructure
– Organisations that provide emergency
services, medical services, government and
financial services

5. Critical Infrastructure 2,, 2013 Slide 5
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

6. Critical Infrastructure 2,, 2013 Slide 6
© Alan Murray-Rust 2012

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

8. Critical Infrastructure 2,, 2013 Slide 8
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

9. Critical Infrastructure 2,, 2013 Slide 9
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

10. Critical Infrastructure 2,, 2013 Slide 10
Programmable Logic Controllers
• Stand-alone units which are associated
with a controlled element or a group of
controlled elements

11. Critical Infrastructure 2,, 2013 Slide 11
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)

12. 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

13. Critical Infrastructure 2,, 2013 Slide 13
Infrastructure control elements
PLC PLC
To SCADA system
Water pipeline
Motorised
valve
Motorised
valve
Flow
sensor

14. 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

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

16. Critical Infrastructure 2,, 2013 Slide 16
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

17. 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.