Language - LabVIEW: Difference between revisions

Revision as of 18:51, 22 March 2012

LabVIEW ..., developed by National Instruments is a visual programming language. You live in a graphical world. Why not program in one?

Introduction

If this is your first time working with a Phidget, we suggest starting with the Getting Started page for your specific device. This can be found in the user guide for your device. That page will walk you through installing drivers and libraries for your operating system, and will then bring you back here to use LabVIEW specifically.

LabVIEW is capable of using the complete Phidget API, including events. We also provide example code in LabVIEW for all Phidget devices.

LabVIEW can be developed with Windows. OS X and Linux are unsupported as Phidgets have not been tested on those systems..

You can compare LabVIEW with our other supported languages.

Quick Downloads

Just need the LabVIEW documentation, drivers, libraries, and examples? Here they are:

Documentation

API Manual

Example Code

Libraries and Drivers

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 the following, The installers in the Quick Downloads section put only the phidget21.dll into your system. You will need to manually put the Phidget LabVIEW library 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.
Phidgets LabVIEW library. contains the the Phidget library for LabVIEW. You need to place the library into your LabVIEW functions palette. Instructions are explained in the Write Your Own Code section.

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 Downloads 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.

Front Panel

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.

Block Diagram

The block diagram shows the logic of the application.

Block Diagram

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

Run

4. The application will run.

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 clicking 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 add the Phidget LabVIEW library to your development environment. To begin:

1. Navigate to Tools → Advanced → Edit Palette Set to modify the functions palette.

Edit Function Palette

2. The functions palette will show up. Right click an empty area, and select Insert → Subpalette.

Insert Function Palette

3. Next, select Link to a directory.

Link to a library

4. Make sure you have the Phidget LabVIEW library and examples in the Quick Downloads section downloaded and extracted. After extracting, you will find the Phidgets folder. In LabVIEW, browse to the Phidgets folder, and select Current Folder.

Select Phidgets library

This will load the Phidget LabVIEW library into the functions palette. You can find all the functions that pertain to Phidgets inside the Phidgets palette.

Phidgets LabVIEW Library

5. Click on Save Changes in the Edit Controls and Functions Palette Set window.

Save Function Palette

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:

API Manual (This is the complete set of functions you have available for all Phidgets)
Device Specific APIs - The one for your Phidget can be found in its user guide.

To learn the details behind opening, configuring, using, and closing your Phidget, try the General Phidget Programming page. That page also describes using the Phidget in an event-driven manner and in a traditional manner, both of which are available in LabVIEW.

Common Problems and Solutions/Workarounds

Known Issues:

Phidgets do not always work cleanly in Labview. Sometimes they do not appear, sometimes they work veeerrryyy slowly. No known fixes yet, hopefully soon.

@@ Line 106: / Line 106: @@
 Next comes our API information, with syntax for all of our functions:
-{{UsingAPhidgetInCodeGeneral|both of which are available in Visual Basic 6.0|[http://www.phidgets.com/documentation/COM_API_Manual.pdf COM API Manual]}}
+{{UsingAPhidgetInCodeGeneral|both of which are available in LabVIEW|[http://www.phidgets.com/documentation/LabVIEW_Manual.pdf API Manual]}}
-===Example Flow===
-{{ExamplePseudocode|In Visual Basic 6.0, you can name these '''event''' functions whatever you like.  You will then pass them as function pointers to the Phidget library below in the Main Code section.  This hooks them into the actual events when they occur. <br>
-In the example code, the event functions common to all Phidgets are called things like '''AttachHandler()''' and '''DetachHandler()''', etc.<br><br>
-Some event functions will be specific to each device, like when a tag is read on an RFID board, or when a sensor value changes on an Interface Kit.
-Other functions are given in the examples to show you more detail on using your Phidget.  For example, '''DeviceInitialize()''' will show what needs to be set up for your Phidget before using it.
-|Creating a Phidget software object in Visual Basic 6.0 is specific to the Phidget.  For a Phidget Spatial, for example, this would involve creating a PhidgetSpatial object.  The examples show how to do this and other API functions|
-[http://www.phidgets.com/documentation/COM_API_Manual.pdf COM API Manual]}}
 ==Common Problems and Solutions/Workarounds==
 {{KnownIssues|Phidgets do not always work cleanly in Labview.  Sometimes they do not appear, sometimes they work veeerrryyy slowly.  No known fixes yet, hopefully soon.}}

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