- Internet of things was hard to define.
It's just the loose conglomeration
of devices that are talking some form of radio protocol.
Maybe, maybe they're plugged in.
They're talking on the internet
who knows everything is a thing on the internet of things.
Operational technology on the other hand is strictly defined
in that there's a bunch of processes
and standards that operational technology must conform to.
And the reason it has to conform to very strict standards
are because the critical infrastructure
that operational technology operates on.
Things like oil and gas pipelines,
the electrical grid, planes, boats, cars, utilities.
This is critical infrastructure
that the world relies upon in order to, you know
have its day to day life.
Operational technology as defined by hardware
and software to monitor and control physical processes,
devices and infrastructure.
So we have industrial control systems, ICS,
our devices systems controls and networks.
Two, manage industrial processes
and Distributed Control Systems fall into
the industrial control systems, bucket SCADA.
SCADA as defined by, or rather
if you were to expand that acronym
Supervisory Control and Data Acquisition.
This is a standard for gathering data from sensors
and talking to things to, for example, actuate.
So open this valve close this valve,
this is extremely well defined.
SCADA networks, SCADA networks are what you see
when you're talking about the power grid
or oil and gas pipelines.
As I just mentioned in the previous slide.
These distributed control systems listed here
are used to manage local controllers
that are operating these various devices
as part of the SCADA network.
There's a quick overview of the things that you see
in SCADA network.
So SCADA itself, high level process, supervisory management
is a framework for critical infrastructure environments.
You have supervisory computers, there's sort of
a hierarchical deployment of devices within SCADA networks.
These supervisory computers are at the top of that triangle.
They are, you know, monitoring and managing the environment.
Beneath that you have remote terminal units
and programmable logic controllers.
Both of these things are to use and PLCs
are connected to sensors and actuators
in the various environments.
The difference between the two is that remote terminal units
are to use have quite a bit less logic and functionality.
Whereas programmable logic controllers
as their name says are programmable.
So you can put in that, if this happens then do this.
RTUs are quite a bit less complex.
Then you have the communication infrastructure.
This connects the supervisory systems to these PLCs and RTUs
and finally HMIS or Human Machine Interfaces.
These are, you know, actual displays that you touch
and you know, make things happen, right?
For management, monitoring, control.
It's an interface for you to interact with the machine.
Industrial IoT falls
into this Operational Technology Concept.
So we have sensors, monitors and actuators
that are installed on all of these things
you see listed here on the screen.
It's all critical infrastructure stuff
that operational technology is targeting.
High security is an absolute requirement.
So whereas with IoT, security is often an afterthought.
You know, once they get hacked, then they're like,
oh man we should have secured that.
With OT though, security comes first because we're talking
about things that people will die, if you do it wrong.
An example here, the power grid is a SCADA system.
That doesn't mean that it's completely secure though.
I mean, there have been examples
in the media of power grids being hacked.
It is a SCADA system that was hacked.
Why was it hacked?
Probably because something was exposed.
That was part of the SCADA network.
PLCs or programmable logic controllers.
These things are actually kind of fun to play with.
We'll have more information about PLCs further along
in these lessons.
PLCs are essentially ruggedized little computers
that are programmable.
They have IO interfaces.
As you can see here, all these little blocks
in the back right here are used for connecting wires
either digital signals or analog signals.
The programming of these devices is meant to be done
by people who are not professional developers.
It's a simplified method of programming.
Quite often, what they use is what's called Ladder Diagram.
It's a graphical programming language
defined by IEC 61131-3 to program PLCs.
There are four other programming languages that can be used.
Structured Text is seen quite a bit
and you can actually translate provided you have
an application that can translate.
Here's an example of Ladder Diagram.
So we have an OR gate and an AND gate.
You'll notice we have the question
in parallel right here and then series over here.
So in order to you'll notice.
So A and B.
Af A is zero and B is zero, then the output is zero.
So, OR if A is true and B is false, then the output is true.
If this is true or that is true, or they're both true
then the output is true.
If they're both false, the output is false.
And then the AND gate opposite of the, OR gate,
and both of them have to be true
before the output becomes true.
As we can see here
in this truth chart at the bottom of the screen.