PT-100 Temperature Measurement

(1)

Høgskolen i Telemark

Fakultet for teknologiske fag Bachelor i ingeniørfag

(2)

1 INTRODUCTION

In this task, you will learn how to create a program and a human machine interface (HMI) in DeltaV to measure temperature. The equipment we are using is a PT-100 temperature device.

In order to get temperature data, we need to use a transmitter with an output signal 4-20 mA that reflects a temperature range of 0 - 50˚C. We use a 250-ohm resistor to get a 1-5V signal.

The scaling formula is y = ax + b In this case we get y = 12.5x -12.5

(4)

2 PROGRAM

In this chapter, you will learn how to create the program to measure the environment temperature.

2.1 Step 1: Creating a new database

Before we start to program in DeltaV we would like to start on an empty program where no inputs or outputs are used. This is easily done with the use of a database. To avoid adding all the hardware configurations each time, we have premade a database that is empty, but contains the hardware configurations we need.

The First thing you need to do is log on to the DeltaV station with username: Administrator and password: deltav. When this is done choose Windows Desktop. Click on the start-menu and open Database Administration. Double click on Copy Database, choose Student1 from the drop down menu and write your name in the Copy To field. Figure 2-1 is showing you what it should look like. Press copy  Yes  OK  Close.

Figure 2-1 How to set up your database

After you close the Copy Database window, you want to set the database you just made active. To do this double click Set Active Database, this is found in the Database Administration window. Click change (If warning press OK) and select the database you just made and press OK. Your database is now created and active. Close database window to continue.

(5)

2.2 Step 2: Creating a new area

Go to the start menu and run DeltaV Explorer.

Right click on Control Strategies and select New Area. Name it PT-100. Figure 2-2 shows you what it should look like.

Figure 2-2 Creating a new area

2.3 Step 3: Connecting I/O to Analog Input block

Choose Applications from the top menu and click Control Studio as shown in Figure 2-3.

Figure 2-3 Applications

(6)

To measure the temperature you will need an Analog In signal.

Click on IO on the right hand side of the window and choose Analog Input. Drag and drop the Analog Input icon as shown in Figure 2-4.

Figure 2-4 IO Palette

We need to connect the analog input signal to the block. Right click on the AI block you just placed and choose Assign I/O  To Signal Tag. On the Device Signal Tag click the Browse button as shown in Figure 2-5.

Open CTLR-1-HIT  Select TLR-1-HITC01CH01  OK  OK

(7)

To change the name of the block. Right-click on the block, choose rename and type: TT and press enter. The block will now look like Figure 2-6.

Figure 2-6 Temperature transmitter TT

2.4 Step 4: Scaling

To get the program to show the right temperature value, we need to scale the values. In our case we use y = 12.5x -12.5, as described in the introduction.

Start by selecting the TT block. Under Categorized open I/O and double click on OUT_SCALE as shown in Figure 2-7.

Figure 2-7 OUT_SCALE

The property box shown in Figure 2-8 will appear. Change the Engineering unit to V, and set 0% of scale to 1 and 100% scale to 5  OK.

(8)

Next, choose a multiply block from the Math palette in the right menu. Drag and drop. Connect the TT OUT to the multiply block’s IN1 by dragging a line from OUT to IN1. Figure 2-9 shows what it should look like.

Figure 2-9 Connection from AI to MLTY

Next, you need to set a value to IN2. Select the multiply block, down to the left, there is a property window showing. Choose Categorized and double click on IN2. The IN2 Properties window as shown in Figure 2-10 pops up. Set the value to 12.5  OK.

Figure 2-10 IN2 Properties

Now you need a similar block, but this time a subtract block. Find the Subtract block in the math palette. Drag a line from the MLTY OUT to the SUB IN_1 and repeat the procedure from the multiply block where IN_2 is also 12.5. When you are done, it should look like Figure 2-11.

Figure 2-11 blocks

(9)

2.5 Step 5: Activate I/O

Now we need to activate the I/O. Go to Exploring DeltaV. Choose applications  I/O configuration as shown in Figure 2-12.

Figure 2-12 Exploring DeltaV

The list of modules that are connected to the station is shown in Figure 2-13. Right click on CH01 in C01 and enable it.

Figure 2-13 I/O Configuration

(10)

2.6 Step 6: Download

The last thing that needs to be done before we start making the human user interface (HMI), is to make sure everything is downloaded. Right click on Physical network and choose Download physical network as show in Figure 2-14. Press yes, then close.

Figure 2-14 Download Physical Network

Before we make our interface, we need to download the program in Control Studio. Right click on TEMPERATURE and choose Open  Open with Control Studio as shown in Figure 2-15.

Figure 2-15 Open Control Studio

Click the download button as shown in Figure 2-16. Press yes on pop-up.

(11)

3 HMI

To be able to read the measurements from the temperature transmitter we need to create a HMI.

3.1 Step 1: Open a new picture

In Exploring DeltaV, choose Applications  DeltaV operate Configure as shown in Figure 3-1.

Figure 3-1 Exploring DeltaV

Press the + sign on the folder Pictures, then templates and double click on main. You will then get a standard picture as shown in Figure 3-2.

(12)

Delete all the text in the picture so you get a blank picture as shown in Figure 3-3.

Figure 3-3 Blank Picture

3.2 Step 2: Creating interface

Start by adding a text that says “Temperature”. Select A in the toolbar, click somewhere in the drawing area and start writing.

Now we need to add the temperature variable. Click on the ABC100 button from toolbar and change Data Entry Type to In-Place and Formatting Type to Numeric. Check Figure 3-4 to see if your values are matching.

(13)

Next click “…”. Choose Browse DeltaV Control Parameters.

PT-100 TEMPERATURE  SUB1 OUT  CV  OK  OK

Figure 3-5 Expression builder

Stamp the Datalink on the drawing area. Your picture will look like Figure 3-6.

Figure 3-6 Main

You are now going to make a simple thermometer. Open Dynamo sets from the left window and double click on Basic Shapes. Basic Shapes shown in Figure 3-7.

(14)

Choose the shape Polygon162, and drag it into your page. Right-click on the shape and click rotate. Use the corners to turn the Polygon vertically. You can also adjust the size by dragging the corners. Your HMI should now look like Figure 3-8.

Figure 3-8 Thermometer

Next, double click on the shape. Basic Animation Dialog will now open as shown in Figure 3-9.

Figure 3-9 Basic Animation Dialog

Under Fill, click the checkbox Fill Percentage. Fill Expert will now open. Click “…” and Browse DeltaV Control Parameters.

TEMPERATURE SUB1 OUT  CV  OK

In Fill Expert, change Lowest Input Value to 0 and Highest to 50 as shown in Figure 3-10.  OK

(15)

You are now back in Basic Animation Dialog. Click Configure, Polygon162 Animations window (Figure 3-11) will appear.

Go to Color and click “…” next to ForegroundColor. Choose the color blue, this color will show the temperature. Then click on BackgroundColor and “…” and pick grey for the thermometer color.  OK  OK 

Figure 3-11 Polygon162 Animations

Click save and type your name  Save You are now finished with the HMI.

(16)

4 OPERATE

Connect the PT-100 temperature device to TEMP IN connection points as shown in Figure 4-1.

Figure 4-1 Connection

You are now ready to open Operate (run), click CTRL +W.

Your finished program should now look something like Figure 4-2

Figure 4-2 Operate run

NB! If the temperature is too high, try pulling the PT-100 device power out, and then put it back again. This should fix the problem.