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Users are requested to download the LabVIEW 2009 run time engine before performing any experiment. If the Engine is not already installed on user's PC they may download it from the link given below.
Prefered Browser : Mozilla Firefox
To run the LabVIEW files on apple IPAD :
To run the LabVIEW files on iPad we have to download “Data Dashboard Application for LabVIEW”.
Data Dashboard allows us to create custom, portable views of National Instruments LabVIEW applications. Data Dashboard 2.0 is available for the Apple iPad in the Apple App Store.
Steps :
- - - - - Go to Apple website (www.apple.com)
- - - - - Then go to iTunes
- - - - - Next Data Dashboard for LabVIEW
Creating a dashboard :
1. Open Data Dashboard 2.0 on the device. When the application opens we will see the dashboard carousel. To create a new dashboard click the ‘+’ sign at the bottom and select new dashboard.
2. Two options will come to choose the orientation of the dashboard – Portrait or Landscape. We can choose either option.
3. The new dashboard will open and appear as shown below. To place an Indicator go to the controls and indicators and select Indicators.
4. To place an indicator on the dashboard drags it from the pallet onto the page.
Deploying shared variables :
We have to connect the variables before we link dashboard controls and indicators. In case of having network published shared variable deployed, we can proceed to next section connecting the shared variable. To deploy network-published shared variables you will have to create a project in LabVIEW.
1. Go to LabVIEW
2. Select File>
3. Click New Project to create a new LabVIEW project
4. Go to the Project Explorer window
5. Right-click My Computer and select New then Variable. It adds a shared variable to the project
6. Right-click the shared variable and select Rename. Rename the shared variable DDVariable1.
7. Right-click My Computer and select New>>VI. This VI will periodically update the shared variable value with a random number.
8. Save the project.
9. Add a While Loop to block diagram of the VI.
10. Place a Random Number (0-1) function and a Wait (ms) function inside the While Loop.
11. Right-click the input terminal of the Wait (ms) function and select Create>>Constant. Set the value of the constant to 500 to update every half second.
12. Drag the shared variable you created from the Project Explorer window onto the block diagram. Right-click on the shared variable and select Access Mode>>Write.
13. Wire the output terminal of the Random Number (0-1) function to the input terminal of the shared variable.
14. Right-click the input terminal of the stop terminal and select Create>>Control (It creates a button for stopping and starting the program).
The block diagram should resemble as shown in fig.
Connecting to shared variables :
On completion of placing the indicators and deploying shared variables it’s time to link dashboard to shared variables.
1. Tap the Chart indicator and select the Data Link icon shown in the following image to open the Connect dialog.
(In the fig. the dotted border is the chart indicator and the bold red border is the data link icon)
2. Select Shared Variables in the Connect dialog.
3. Enter the IP address or the DNS server of the shared variable in the given text box and then click on the Connect button to connect the Share Variable Engine.
4. Tap the name of the library that contains the deployed shared variable. Then, select your shared variable, as shown below. The data type of each shared variable is listed below the variable name.
5. Repeat steps 1-3 for your Numeric indicator.
6. Data Dashboard 2.0 only allows to select shared variables that are compatible with the data type of the selected indicator. In this example, the deployed Shared Variable is a double-precision floating point number, which can be displayed using a Chart or Numeric indicator.
7. We can customize the chart's appearance by selecting the properties menu shown below.
8. Run the dashboard by selecting Play button in the upper right hand corner. The running dashboard appear as follows -
Deploying web services :
In this section we will be creating a Web Service and a Web method to connect to the data dashboard. The following steps describe the process of building a Web Service with LabVIEW.
1. Create a new LabVIEW project.
2. Name the project Data Dashboard Demo.
3. Add a new VI to the project.
4. Name the VI DDDemo-Method.
5. Place a Random Number (0-1) function on the block diagram.
6. Right-click on the output terminal of the Random Number (0-1) function and select Create>>Indicator.
7. Edit and rename the indicator label as DDVariable1, as shown in the following image.
8. Assign the indicator to a connector pane terminal for the VI so that the Data Dashboard can monitor the output of the Web method VI.
a. On the front panel, select a connector pane pattern.
b. Click a terminal of the connector pane. The terminal turns black.
c. Click the DDVariable1 indicator on the front panel. A marquee highlights the indicator and the terminal changes to the data type color to indicate you connected the terminal, as shown in the following image.
9. Save the project.
10. Create a new Web service.
11. Right-click Build Specifications in the Project Explorer window and select New>>Web Service (RESTful).
12. On the Information page, select the name of the Web service and destination directory using the default settings.
13. Use the Add Item arrow on the Source Files page to move the VI from the Project Files tree to the Service VIs tree.
14. In the Configure RESTful VI dialog box, specify the following settings for the Web method VI.
15. Build the project.
16. Right-click on Data Dashboard Demo and select Deploy to deploy the Web service application.
Connecting to web services :
On placing down indicators and deploying Web Service, we can link dashboard indicators to Web methods. There are two ways to connect to a Web method, polling and calling. Polling a Web method calls the Web method continuously every .3 to 30 seconds as specified by the user. Calling a Web method only calls the Web method when the Call button is pressed. To have a clear view, we will use a polling connection to continuously populate the data on chart and indicator.
1. Tap the Controls and Indicators icon
2. Select LabVIEW Web Services.
3. Drag a Poll Web Service to the dashboard and select the Web Link icon(bordered red)
4. The Web Services connection dialog will open and we will be able to enter the DNS server or IP address. Click Connect.
5. Next, a display of Web Services is hosted on the target.
6. Select Web Service and then, the Web Method to link to our poll.
7. On connecting successfully, the Web Link icon turns green. To link our Poll to an indicator select the
adorner as shown below.
8. We will see an overlay that shows indicators on the dashboard that can link to our variable.
9. Click the Chart to link the Web method variable to the chart indicator. In case we can also select new create new indicator.
10. On successful completion of linking Web method variable, we will see the mappings as shown below.
11. Repeat steps 1-7 to link Numeric indicator to Web method. The dashboard should appear similar to the following image after running -
References :
National Instruments (http://www.ni.com/white-paper/13757/en).
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