Language - LabVIEW

LabVIEW ..., developed by National Instruments is a ...

Getting started with LabVIEW

If you are new to writing code for Phidgets, we recommend starting by running, then modifying existing examples. This will allow you to:

• Make sure your libraries are properly linked
• Go from source code to a test application as quickly as possible
• Ensure your Phidget is hooked up properly

Windows(2000/XP/Vista/7)

Description of Library Files

LabVIEW programs on Windows depend on two files, which the installers in Quick Downloads put onto your system:

• phidget21.dll contains the actual Phidget library, which is used at run-time. By default, it is placed in C:\Windows\System32.

If you do not want to use our installer, you can download the phidget21.dll and manually install it where you want; refer to our Manual Installation Instructions.

We include instructions on using our examples and writing your own code.

Use Our Examples

To run the examples, you first download the examples found in the Quick Downlods section and unpack them into a folder. Here, you will find the examples folder, which contains vi programs for all the devices. Each vi example demonstrate the usage of a few of the device's properties. To get a broader understanding of the device, you should take a look at all the vi examples inside the directory for your device. If you aren't sure what the software example for your device is called, check the software object listed in the Getting Started guide for your device.

1. Inside the examples folder, navigate to the directory for your device.

2. Open up any .vi of your choice in LabVIEW. In this section, the Sensor to Output Example.vi of the PhidgetInterfaceKit examples will be used.

You will see the front panel of the example. The front panel shows the user interface of the vi program.

2. Next, let us take a look at the block diagram by navigating to Window → Show Block Diagram.

The block diagram shows the logic of the application.

3. The only thing left to do is to run the examples! Navigate to Operate → Run.

4. The application will now run.

You can determine that your device is connected to your application if you see the indicator for attached turn green and the correct serial number is displayed. These features are available in most of the example vis' we provide.

5. When you are ready to terminate the application, click on the button to release the hold on the device. Please keep in mind that the application may not terminate properly if you stop it by clickking on Operate → Stop.

Once you have the LabVIEW examples running, we have a teaching section below to help you follow them.

Write Your Own Code

When you are building a project from scratch, or adding Phidget function calls to an existing project, you'll need to configure your development environment to properly link the Phidget COM library. To begin:

1. Generate a new Standard EXE project.

2. Next, navigate to Project → Components to add the Phidget ActiveX objects into your project.

3. The Components menu will show up. Browse for Phidget21COM.dll and add it. By default, it is placed in C:\Program Files\Phidgets. Accept the changes.

4. Navigate to Project → References and ensure that the Phidget COM library is selected.

5. Navigate to Project → Project1 Properties, select the Make tab and ensure that the Remove information about unused ActiveX Controls checkbox is unchecked.

6. Then, you will need to declare and initialize the Phidget ActiveX object for your device.

The simplest method is to place the Phidget ActiveX object from the toolbox directly onto your form. If the toolbox is not present on your screen, navigate to View → Toolbox to show the toolbar. Next, find the ActiveX object for your device in the toolbox, and double click it to add it to the form.

Alternatively, you can dynamically create the Phidget ActiveX object in code. For example, for an PhidgetInterfaceKit, you would type:

Dim WithEvents PhidgetInterfaceKit As PhidgetInterfaceKit

Private Sub Form_Load()
   ...
   Set PhidgetInterfaceKit = Controls.Add("Phidget21COM.PhidgetInterfaceKit", "PhidgetInterfaceKit")
   ...
End Sub

The object name for each type of Phidget is listed in the COM API Manual. Please see the examples on how to add a reference to your particular Phidget.

The project now has access to the Phidget function calls and you are ready to begin coding.

The same teaching section which describes the examples also has further resources for programming your Phidget.

Follow the Examples

By following the instructions for your operating system and compiler above, you probably now have a working example and want to understand it better so you can change it to do what you want. This teaching section has resources for you to learn from the examples and write your own.

Next comes our API information, with syntax for all of our functions: