OK we are back and we're going to get a little bit deeper into emulation and we are going to perform
a dry run on our program.
Now when we first test this program it is ideal if we can actually tested on appeal see which is not
connected to any inputs or any outputs.
Possibly it's connected to a test stand which has switches to simulate digital inputs.
It has resistors or potentiometers set up to simulate analog inputs but it's not always possible sometimes
as soon as that people see comes in.
It's hooked directly into the machine or sometimes we're programming from the other side of the world
and we never even see the PLC.
So in that case you can go ahead and do a dry run on an emulator but if possible and you can get access
to the sea without it being connected it's always best to drive around with the actual PLCC.
In our case we're going to be dry running on the emulator.
So we've got our PLCC program in RS logic's 500.
It's already connected online with the emulator which is running the program.
And now I'm going to go ahead and bring up the age of my which was developed in factory talk view studio
s e which is site edition that creates h in my programs that run on a computer rather than on a dedicated
HDMI screen.
So once this loads we'll be able to see the process graphics of this system and we're going to be able
to start simulating machine functionality live right now just as it would be working if it was connected
to a live system.
OK.
Almost started up.
And there's our graphic we see it looks a little strange because it's still establishing communications
.
Once it gets communications then everything knows what color to be and what numbers to fill in.
And then we have a viable process graphic.
So let me walk you through this mess of an HMI head that I've developed for this course in the top left
of our window.
We have to push buttons system on and system of and below system off.
We have a status indicator which is telling us what mode our systems in.
Below that we have blower control the top being an indicator that says The Blower's either running or
not running.
Then we have our three buttons blower and hand off Arto.
That's our agio a control.
And then below that we have an indicator telling us which motor our blower is actually in on our top
right.
We have a tank alarm indicator which is going to turn either green or red depending on whether we have
alarms or not.
The tank alarms consist of a high high level and a low low level.
We have temp alarms which consist of a high high temperature low low temp.
And we have pump alarms which consist of a low flow condition or a high pressure condition.
Below that we have our familiar alarm reset and alarms silence buttons.
And then if you see these two blue squares down towards the bottom on the left and right to the left
we have some set points for temperature a high high set point and operating set point in a low low set
point the high high and low low being a launch conditions the set point being the value that we're sending
to our P-adic control and asking it to sustain and the blue box on the right we have our four basic
analog limits.
We have low low low high and high high.
There is an analog sensor detecting level in this tank but we also have a high high high low and the
low low switch.
Now in a normal tank you're not going to have that much redundant controls Although you might have one
high high switch or a high high and a low low switch.
It's very doubtful you're going to have a high and a low but in this case we do that strictly for demo
purposes.
We have here a discharge valve which is where the water is leaving the tank and that Valve is going
to open or close and change colors.
So is the pipe determining whether or not there's flow through that line.
We have a level indication in the bottom of that tank which is giving a scale representation from zero
to 100 percent of our level on our heater.
We have the actual temperature that we're reading below 104 degrees Fahrenheit and above that we have
a heater output percentage on a scale of 0 to 100.
Then we have our pump and our blower which all turn red or green depending on whether they're energized
energized.
So right now our systems down.
Let's go ahead and click system on.
And now we see our blower comes on and the blower and its pipe turn green and so this pipe to the right
going out because that's where the blowers venting out from our pump is off at the moment.
And if we look at our discharge valve that all turned green so we know that's energized.
So if we look in our appeal see program right now let's go ahead and click into digital outputs.
And here we can see exactly what our APRC program is doing if a bit is energized.
You see how it's highlighted green along the run and then forbid some de-energized.
You see that it's not highlighted green.
And likewise on the right for actual outputs we can see them either highlighted green or not highlighted
green depending.
So our blower is highlighted green here.
And when we come to our HMI program since we have an animation for color programmed onto that blower
it's turning green because right now that bit that it's looking at is energized.
So let's test our blower H.O. way if we click off our blower turns off if we click auto then our blower
comes on because we're running but if we turn our system off then the blower shuts off.
If we put our blower in hand our blower runs even though our systems off and we can turn our system
on and off.
And because our blower is in hand it'll stay running.
So it looks like our controls are working exactly as desired.
So now let's turn our system back on and finish this dry run up.
The next thing we want to look at is our pump.
And we say we want to check and see if our pump comes on when it's supposed to and goes off when it's
supposed to.
Well the way this pump is programmed it's going to energize when the level in the tank gets down to
the low level and it's going to de-energize when the tank level reaches the highest point.
So to test this let's go ahead and change our low level to something higher than the water level in
the tank.
And after a brief delay our pump should energize if everything's working correctly.
So I'll go ahead and set that to 67.
And after five seconds our pump turns green.
And what happens next.
All of a sudden our pump turned red again and we see that we have a pump alarm.
So let's go into the program and see why we have that pump alarm.
So we'll click into our alarms ladder and we'll scroll down to the bottom where we have our categorical
alarms.
And here we have our pump categorical alarm and we see that's been triggered because of a low flow along
.
So when we scroll back up to see our low flow alarm we see right here that this is where the alarm occurred
.
And this is the condition that triggered it.
Our fuel pump was energized but our flow switch never closed which means our pump was turned on and
energized and running but it didn't create flow for five seconds.
So the program shut off our pump to protect it from cavitation.
So that's how we can see that that alarm is working.
Now when we go back to our HDMI program we can click our alarms silence button and that's going to terminate
the notification of the alarms.
You see everything turned green again up here.
But when we go back to our program we see that even though our notification is now de-energized the
alarm condition is still present.
So our alarms silence is working as desired.
Now we can click our alarm reset and make sure that it went ahead and sure enough disable that alarm
but that alarm is going to come back in five seconds.
Once our pump tries to run again and sure enough that works exactly as we designed.
So that's how we do a dry run on a system.
We need to go through our program and test every single function every single alarm every single device
every agio way control.
We need to test every set point every button every display on our HDMI and testing everything on a full
size program is a pretty time consuming process.
But it's a hundred percent necessary part of this process in the next section we're going to look at
first thing I know toggling bits and how to make the PLC think something is actually happening in the
real world that isn't and that's going to be the second half of conducting a dry run.
So stick around and we'll get into that functionality next time.