- Hello, this is Andrew from
DPS, and I want to give you an updated SCADA tutorial today. Our original SCADA tutorial video has been the most popular video on our
channel for over nine years, but that does make it about a decade old and technology does change over time. So I want to walk through
some core SCADA concepts again and give you some tips and
tricks that you can use. Just as an absolute basic refresher, SCADA is an acronym
for Supervisory Control and Data Acquisition, so
the first piece there, you have an ability to control something, and data acquisition, you're gonna be able to monitor it, to collect
information about it. And any SCADA environment
has two major pieces. First you have the process, or the system, or the machinery that you have that necessitate remote monitoring control. Why is it that you want to remotely monitor things and control them? What is that system if you're a factory, if you're a power distribution,
whatever your operation is? That's a good way to sum up
number one, your operation. And then number two is the SCADA system. So now that you have this
thing that you need to remotely monitor and control, how
are you gonna pull that off? What system is gonna
give you those abilities? So those are the two
pieces, your operation and then the SCADA system itself. Where is SCADA used? You'll see it in a lot
of different industries. Power utilities is a big
one, water and sewage, buildings, facilities, environments, manufacturing, so if you
have some kind of a factory, you're gonna need some
kind of a SCADA system to track everything and
control things when they need to be changed, mass
transit and traffic signals, anytime you have trains
moving around or cars moving around, traffic lights
changing, these are complicated systems and you need an ability
to know what's happening and issue control commands
when they're required. You might need SCADA if
you need uninterrupted power and a protected environment. So if you have, say,
a remote telecom site, or a server room, a data center, a factory that has to be in certain
temperature requirements, whatever it is, if you
need to keep power flowing to something and have
the environment protected so the temperature is in
spec, the humidity is in spec, there's not water on the
floor, you need to have good control, that's a
reason to have SCADA. Number two, if you need
to know in real time the status of your complicated system, there's no way that you can
keep track of it yourself. You can't run around, if
it's spread out across a large area, you can't be driving around, you need to have everything
coming right to your desk. So that's what a SCADA
system is going to do. And if you need to monitor and
control at remote locations, as I say you can't be driving around. So even if it were possible
in a factory environment to run around and even
remotely have tabs on things, as soon as you start to have
sites that are spread out across more than a few miles
that's never gonna work. And SCADA is going to give
you some key abilities. You're going to be able to look at things real-time and historically
like temperate, humidity, battery level, voltage, fuel level. The graph here is air flow and temperature for an HVAC system that's
controlling the temperature in a key room so that is another
thing that you can monitor. You're going to be able
to detect and correct your problems quickly, so SCADA gives you an almost psychic ability
or situational awareness over your entire
operation, and then as soon as you spot them, you can
issue control commands. You'll be able to eliminate
bottlenecks and inefficiencies. You'd be surprised, remote
monitoring isn't just this is going wrong, it's
an ability to log things over time and say well this
is repeatedly going wrong. Why is that? Why am I wasting so much
effort in this one area? And you can find that you'll
be able to make an adjustment to your system, so that is
a huge advantage of SCADA. The insights you're gonna
get into the physics of your operation are really powerful. And finally, you're going
to be able to control a bigger more complex process
without having to have a huge army of experts, and
really just a huge army at all. It is a force multiplier,
so the team you do have with the training that you've given them are going to be able to
accomplish a lot because the system provides a lot of leverage. It tells them maybe what to do. You could database in some
response instructions. It's just giving them a nice,
clear, intuitive picture of what's going on and it
makes it so much easier to manage a complicated system. So SCADA basically falls
into four basic functions, and if we look at the
diagram on the right, data acquisition being the first one, so that's in the lower
portion of the diagram where the RTU is and that is
a kind of a collector device, so that could be pulling
in contact closures, sensor data, protocol data,
we'll get into some of that on the next slide, but it's
collecting things essentially, it's collecting data of certain kinds. And then there's data communication. So once you've got that data collected, it's gotta go somewhere, you might have a lot of different RTUs in
different locations spread out. How do you get them all to one place? And so that really revolves
around the protocol that the RTU will use to
communicate and what transport. Like is it network or is it
cellular or even satellite, how is it going to talk back
to the central collector which we call the master or the HMI? I'll get into that in a minute. Then there is data presentation. So once the HMI or the master
has collected all that data how is it going to show it to you? Are you going to get a text message? Is it going up on a screen? Do you see a map or a diagram showing how your process is flowing? Maybe you have different
gauges that show analog values. What is the data and how is
it going to be shown to you? And then finally control, and this is really where we move in reverse. When you can issue a control command, you do that from your master
and it goes down to the RTU in the relevant location
and then that's going to be executed by the RTU
to turn something on or off or change a flow rate or
do just about anything. So let's get deeper into
part one, data acquisition. You want to collect information
from all reasonable sources. And I say reasonable
because you don't want to go overboard, you
don't want to go overkill, but contact closures are
common, so if you have a piece of gear that
latches a relay to tell you hey I'm running right
now, or I'm overheating, or I'm a radio system and I've
got a high level of noise, whatever that is, most
manufacturers of equipment will give you at least a few relays to say hey, I'm having a problem. So if you have a RTU
that has discreet inputs, you can wire those in and then you'll have an ability to monitor those. Protocol inputs are similar,
but those are inputs that are based around a
communications protocol instead of a physical contact closure. But it's the same basic
premise, the device can send a message,
your RTU can pick it up, and then process it,
and then some messages can actually go straight to the master. IP cameras, that's visual surveillance, and some are actually smart
enough to do inspections. So if you have a manufacturing line, you can say well this widget
is a little bit different than all the widgets
that have come before, so I'm gonna throw up a red flag. But it could also be just
simple things like surveillance. Serial output, some devices
will have a serial port and that can give you access
to say, Modbus protocol over serial, but there are
a variety of different, you just need to consult your
manufacturer for the equipment and see what you can get
out of that serial port. And then door controllers,
if you have a high security environment, being able
to see what's going on with your doors is important,
and so a smart door controller gives you some kind of output where it can tie into your SCADA system. The last two points here
in data acquisition, you want to give yourself
some room to grow later. So if you're selecting an
RTU, don't size it exactly to the number of inputs
and outputs you need to do your monitoring and controlling, give yourself a little
breathing room because as you learn more,
you're gonna find things and when you reach a certain point you'll wish you had a little bit more. But at the same time, don't
buy gear that's overkill. If you need four contact closures, don't buy one that has 128 inputs. That's just nonsensical. So maybe doubling your
current requirements is reasonable, but don't go overboard. This is an example of some sensors. DPS actually makes these,
and they are available in a variety of different configurations. This is temp and air flow,
you can have vibration, temperature, you can take
in a fuel level sensor from a propane tank or a
diesel tank, wind speed, you got a lot of different sensors, and this is just one
example of non-equipment that you can monitor if your
equipment isn't smart enough. So if you have a device that
doesn't monitor temperature that's okay you can just
slap a simple little sensor next to it and now you are
monitoring temperature. So external sensors allow
you to bolt new things into your system and collect
data from the physical world that your other equipment
doesn't automatically. Okay then the second
piece, data communication. Two basic pieces, protocol and transport. So first, what is the protocol
that it's going to use? Some common protocols in the SCADA world include DNP3, Modbus, in a
more telecom type environment you might see SNMP, it's
just a very common protocol, and there are lots of
others, some manufacturers will try to trap you with
a particular protocol that only they support, but
sticking with a common standard is your best bet, and it's
likely if you're in SCADA that you have one of the
three that I've shown you. And then what transport? How are you going to send data? Sure you're gonna use one of those protocols, but across what? Is it gonna be a network link? Are you going to have serial? Are you going to have a cellular modem? You can even have a
satellite link nowadays, those are coming down in price quite a bit and the bandwidth is going up, so how is it you're going to communicate? What is the link between your remote RTUs and your central master or HMI? Next, data presentation. Now that that data has all been collected in a central collector how are
you going to know about it? It might be a map like the one I've got in the top right corner here. You can get an email, we
can send you a text message, your HMI console can have a
variety of different screens. It could be a map, but it
could be an analog gauge, it could be a big listing,
however you want to see that. Instead of a map, if you
have a factory you could do some kind of a diagram showing the flow through the factory, it doesn't
have to be a geographic map. You can show some kind of process diagram and have little icons that change color when things are going right or wrong. You can even have voice messages
be rendered out on radio. So if you have staff
with hand held radios, really important status changes can be rendered as radio voice messages. And that same voice message
could also go out on a phone so it can dial or have a cell modem to be dialing people to let them know, especially in the middle of the night. If it's a really serious
situation, hey you've got a problem, you need to respond. And you can have summary lights too. If you're in an environment
where maybe a control console is good, but it's not vibrant enough, you want to have some
dedicated beacon lights that tell people in the
room you have a problem, you need to go log onto your console. You can do that to get a little more of an attention grab when
something is changing. This is an example of a text message. You can see this is from more
of a telecom environment. You can see generator is
running, door is open, channel bank alarm, so
these are just things that have gone wrong out at the site and you need to know about and
they go right to your phone. So having good, clear
descriptions is important. You can see there's
also time stamping here and date stamps and just
good clear descriptions. It's very important, if you
have a cryptic text message there's just nothing worse because now you're racing around trying
to figure out what's wrong. You need to do a good job with databasing and be sure you choose
equipment that gives you this kind of flexibility
to have a good description. And then the last part
of SCADA is control. And a couple key questions here, you need to ask yourself what outputs do you have? So we're back down at the
bottom of the diagram here where the RTU is and you
can see on the left side of that RTU diagram control relays. So that's one way you can do controls. You can latch contact
closures and equipment that has discreet inputs can pick that up and this is a good way
to fire up a generator or turn on HVAC units,
do just about anything. A lot of devices can accept this. A good rule of thumb, if it
has a button or a switch, you can undo the wiring
there and wire it into a control relay and you
can simulate the flip of that switch or the press
of that button with a relay. So these very flexible,
very low level outputs. You can also do things like
send SNMP traps to a device. A lot of devices that
communicate with SNMP can take in a trap message
and you can tell a server to shut down or just about any piece of equipment to do a variety of things. So if you can take in a message like that, that's certainly a good idea,
and even if you don't have SNMP equipment, if you have
DNP3 or Modbus, you can send a protocol message as long
as your RTU is compatible. So just be sure you get equipment that supports the protocols you need. You can issue controls in one of two ways. You can do them manually, so
you can look at the situation on your screen, understand
what's going on, and then press a button
on your keyboard that says let's issue the control,
let's toggle this, let's turn something on,
let's turn something off. But even better would be an
automatic response, and this is what I have on the diagram
on the right side for you. This is an example, it's
pretty straight forward, of someone who had a dehydrator involved in a telecommunication
system, and it should only run for about 10 minutes but it
had a bad habit of sticking on and burning itself up and
that was a huge waste, you had to buy a new one,
it was just a big problem that cost money and it was just wasteful. So, what this person did
was to configure a timer into the SCADA system to
say if this dehydrator has run for more than 20
minutes, which is double what it should have run,
we're well on our way to 30 minutes where it's gonna burn up, you need to tell me that immediately. So you set a timer for 20 minutes, and you say I want to know immediately when it hits 20 minutes
after it first turned on. Now that is a automatic
alarm, it's synthesized, it's smart, it's good, but
then once you have that you can tie a control relay to it. So as soon as you hit that 20 minute mark we can throw a control relay switch which might just kill the
power to the dehydrator. Maybe if we want to be
a little more delicate we can send it a protocol
message to tell it I don't care what you think you're
doing, please turn off now. So you have a couple
different options to actually execute that control, but
the point is when a certain condition is detected,
you can then execute an appropriate control
command automatically and then the system will
log it so you'll still know about it, but if you got up from your desk and in this example we had
just a 10 minute window to prevent some damage, the
system will take care of it automatically, you don't have
to be sitting at your desk all the time waiting for
that alarm to come in. One of the last things I want to talk to you about are RTUs versus PLCs. So a PLC is a Programmable
Logic Controller, and those are very common
in SCADA environments and if you are experienced
they can be pretty powerful. You can program just
about anything because you're actually writing
code, but conversely you have to program
everything, so there is a steep learning curve there, so if
you're just getting started with SCADA you have a choice
about your architecture and you may want to look at an
RTU or a Remote Terminal Unit. And they're different from PLCs even though they do the same role. You have built in intelligence,
so you actually have usually a web interface when
you can configure the thing and you're not programming
it, you're just setting things up, you're typing in the
descriptions for your various alarm conditions, you're setting
up rules that say if this then that, but you're not
programming it from scratch. You're also likely to
get firmware upgrades for new functions because
they're actually functions built in, so your manufacturer
may engineer a new feature and then release it for
you to upgrade your unit, whereas the PLC, you're
programming it from scratch so any new feature is really up to you. So RTUs definitely have
an easier learning curve and if you're just getting started it's definitely an option
you should consider. I want to leave you the
final thought from one of our clients who told me,
the further you get with it the more things you realize
you can monitor and save money. And this is a guy who has
been incrementally improving his system over the last six years or so, and he started off with
a pretty basic set up and he's just layered things on and on. And you get to a point where
you've drastically reduced the time and effort and
stress related to managing your system, and a lot more
things happen automatically. So if you'd like anymore
information about SCADA please send me an email or give me a call. Sales@dpstele.com is the email. You can call us here at
DPS at 1-800-693-0351. And also please just check
out some more of my videos on YouTube and I hope they help you out.
