Introduction to LabWindows™/CVI

NI LabWindows/CVI is a proven ANSI C development environment for test and measurement that greatly increases the productivity of engineers and scientists. For more than 20 years, C developers have used LabWindows/CVI to develop high-performance, stable applications in the manufacturing test, military and aerospace, telecommunications, design validation, and automotive industries. LabWindows/CVI streamlines development in these areas with hardware configuration assistants, built-in measurement libraries, comprehensive debugging tools, interactive execution capabilities that developers can use to run functions at design time, and advanced analysis and scientific user interface tools.

NI LabWindows/CVI helps protect me from test system obsolescence by consistently maintaining backwards compatibility. Using LabWindows/CVI, not only can I continue to reuse C code that I created 11 years ago, but the code also executes faster with the optimized compiler integration. The National Instruments commitment to backwards compatibility with LabWindows/CVI makes it the de facto standard for military/aerospace test development. - Dave Dunham, Senior ATE Systems Engineer, MTI

Integrated Environment

The LabWindows/CVI development environment, as shown in Figure 1, includes a workspace window that is divided into five main areas – the Project Tree, the Library Tree, the Window Confinement Region, the Output Region, and the Debugging Region.

Figure 1. LabWindows/CVI features a streamlined tabbed workspace in which you can quickly develop, debug, and manage large applications.

The integrated workspace provides an intuitive, convenient interface for creating and managing large projects. You can also customize each of the areas to fit your specific development style and preferences, and integrate with source code control, requirements management, and data management systems.

Watch a seven-minute demo to learn how to develop applications with LabWindows/CVI.

State-of-the-Art Hardware Connectivity

Often the most critical process in a measurement application is connecting to an instrument and taking measurements. LabWindows/CVI simplifies the task of connecting to and communicating with a wide variety of instruments. With the LabWindows/CVI built-in measurement libraries, you can quickly acquire data from GPIB, USB, serial, Ethernet, PXI, and VXI instruments using the built-in instrument I/O libraries or using built-in instrument drivers.

In addition, LabWindows/CVI streamlines data acquisition and instrument connectivity capabilities with interactive measurement tools. It provides two measurement assistants, which simplify the acquisition process.

LabWindows/CVI reflects the commitment of NI by fully leveraging the latest NI technologies available – including the DAQ Assistant and Instrument I/O Assistant ... to greatly increase my efficiency and productivity. - Pierre Duriez, Industrial Computing Manager, Fuji Electric

DAQ Assistant

In addition to the integrated NI-DAQmx data acquisition library, LabWindows/CVI features the DAQ Assistant, an interactive interface to the NI-DAQmx driver framework. The DAQ Assistant, shown in Figure 2, interactively defines a measurement task, determines the measurement capabilities of the data acquisition device you specify, and generates code modules that contain the acquisition functionality. The tight integration of the DAQ Assistant and NI-DAQmx with LabWindows/CVI offers engineers who perform data acquisition the most efficient, productive way to take measurements in an ANSI C environment.

Instrument I/O Assistant

Engineers and scientists in the test industry recognize that easy connectivity to various instruments from different vendors is crucial when selecting a software package. LabWindows/CVI, along with NI LabVIEW software, is an industry leader in instrument control and connectivity through an Instrument Driver Network of more than 6,000 instrument drivers from more than 275 vendors. You can use these drivers to easily program instrument control applications. LabWindows/CVI takes instrument control to the next level of productivity with the Instrument I/O Assistant, with which you can generate code to communicate with devices such as serial, Ethernet, and GPIB instruments without using an instrument driver.

Figure 3. The LabWindows/CVI Instrument I/O Assistant automatically parses instrument data, generates reusable code, and interactively defines basic communication.

The Instrument I/O Assistant offers a simple interface you can use to quickly prototype applications and autoparse instrument data, without any programming. You can easily import the generated code into any existing application, which removes the tedium of writing instrument connectivity, basic communication, and string parsing code. By writing two lines of code, you can invoke more than 300 lines of code created by the Instrument I/O Assistant and quickly focus on taking measurements.

View the LabWindows/CVI instrument control white paper series.

Scientific Advanced Analysis

LabWindows/CVI provides powerful algorithms and functions designed specifically for measurement analysis and signal processing. The LabWindows/CVI functions for analysis include signal processing tools you can use to condition and transform your signal using smoothing windows, digital filters, and frequency-domain transforms. With these functions, you do not have to write your own algorithms to turn raw data into meaningful information. With the LabWindows/CVI Advanced Analysis Library, available in the LabWindows/CVI Full Development System, you can:

• Extract information from acquired data and unique measurements
• Generate, modify, process, and analyze signals
• Add intelligence and decision-making capabilities to your applications
• Perform inline and offline analysis
• Use common-purpose as well as specialized tools and add-ons
• Take advantage of academic analysis examples

Figure 4. LabWindows/CVI includes a powerful, comprehensive set of functions for analyzing data.

View the complete list of LabWindows/CVI analysis functions.

Visualize Test and Measurement Data

Create professional measurement and automation graphical user interfaces (GUIs) in C without spending months on development. LabWindows/CVI delivers measurement-specific user interface components that you can drag, drop, and extend to create a custom interface to your measurement applications. These controls include buttons, knobs, slides, gauges, tanks, dials, and graphs.

Figure 5. You can create modern user interfaces with updated theme-based controls.

View the LabWindows/CVI user interface gallery.

Support for the Latest PC Technologies

Because industry standards are pushing more open technology, such as multithreading, .NET XML Web services, and Internet-enabled applications, LabWindows/CVI incorporates these technologies.

Multicore Programming

Executing tasks in parallel often uncovers design flaws that go unnoticed in single-threaded applications – especially when correct application behavior depends on the precise timing of execution, memory access, and communication between multiple tasks. LabWindows/CVI not only provides simplified ANSI C thread synchronization functions and optimized threading constructs to address these challenges but also contains several advanced features that simplify troubleshooting and design optimization on multicore systems.

Figure 6. Select a particular CPU from the Highlight CPU Mode option to highlight all thread activity that executed on that CPU.

Learn more about debugging multicore ANSI C applications with LabWindows/CVI.

Microsoft .NET

With LabWindows/CVI, you can take advantage of the latest Microsoft .NET technologies to invoke methods and set and get properties from .NET assemblies. The .NET assemblies are the building blocks of all .NET applications; thus, LabWindows/CVI programmers can use this functionality to call Web services such as those for sending automated e-mails, accessing rich database functionality, and interacting directly with Microsoft Windows API methods including those for viewing CPU use and logging errors.

Internet and XML Libraries

LabWindows/CVI also includes the Internet Library, which you can use to instantly connect your applications to the Web through e-mail, FTP, Telnet, and ping. You can send e-mail or text messages to notify operators of specific events, such as a machine overheating. You also can log acquired data to an FTP server. In addition, LabWindows/CVI contains an XML function library. The cvixml.fp instrument driver includes functions you can use to create and modify XML documents.

Multiplatform Support

With the flexibility of LabWindows/CVI, you can protect your code investment by reusing legacy code in a familiar environment and seamlessly integrate distributed test systems running on Windows, Linux®, or real-time platforms.

LabWindows/CVI Real-Time Module

With the LabWindows/CVI Real-Time Module, you can create reliable, deterministic applications that target dedicated real-time hardware. This module reduces your development time for real-time applications by helping you:

• Reuse existing ANSI C code and the familiar LabWindows/CVI development environment
• Target commercial off-the-shelf (COTS) hardware targets, specifically PXI and PC targets, as well as I/O
• Use a single toolchain for real-time and Windows development

Read the introduction to the LabWindows/CVI Real-Time white paper. 

LabWindows/CVI Run-Time Module for Linux

The LabWindows/CVI Run-Time Module for Linux extends the LabWindows/CVI development environment by allowing developers to create high-performance, stable applications on a Windows system and later compile and run these applications on a Linux target.

Read more about the LabWindows/CVI Run-Time Module for Linux. 

Productive Development Tools

LabWindows/CVI also includes key productivity features with which you can efficiently create end-to-end solutions. Some additional productivity tools include new project and file templates for easily implementing consistent programming style while reducing the amount of redundant tasks performed between multiple applications.

New Project Wizard

It is common for developers on a team to use a consistent code or user interface template when starting new projects. Common settings such as source code control or build options typically have to be reset from project to project if development is performed on different machines. With the new Project Wizard, you can create new project or source files based on existing templates. The templates can apply to file-naming conventions, code documentation, build and target options, and user interface design.

Function Panels

Interfacing with an instrument usually requires the constant exploration of header files and help files. LabWindows/CVI introduced function panels as an easy tool to navigate an API and interactively insert function calls. Help is available for the function itself and each parameter. In addition, you can use function panels to interactively run individual functions with parameters that you specified. With function panels, you can quickly write source code in an interactive window, even automatically inserting ampersand (&) signs before variables to designate memory addresses. In addition, if you are developing a custom instrument driver, you can use the function panel HTML generation capabilities to take the documentation already included in your instrument drivers or in the open source instrument drivers available in function panels and generate Web-ready documentation that can be easily distributed and searched.

The design-time prototype help in LabWindows/CVI is extremely effective in determining the correct parameters for my measurement functions. - Marco Turra, Software Engineer, HI-TEC

Set Next Statement

LabWindows/CVI features the Set Next Statement command, which you can use to skip over code you know is going to fail or investigate code that failed when you executed it. This command changes the next statement to execute while you are debugging.

Editable Data Tooltips

LabWindows/CVI includes editable data tooltips. As you debug your application, you can hover over a variable name in the Source window to view and change the variable value using the tooltip.

Resource Tracking Window

With LabWindows/CVI, you can locate potential resource/memory leaks earlier in the development process with the Resource Tracking Window. This tool records and tracks all resources allocated at run time including dynamic memory, file handles, panels, GPIB/TCP handles, and thread pools. You can also use the tool to easily go to source code, view memory, break on deallocation, and log tracked resources to disk for later review.

The built-in Resource Tracking Window in LabWindows/CVI 9.0 has saved me days of adding custom debugging code to track memory and other resource usage. Now with an integrated solution that requires no changes to my code, I have found multiple memory leaks in a matter of minutes. This new feature is invaluable. - Chris Quick, Software Engineer, Laser Technology Inc.

NI TestStand Test Management Software Integration

NI TestStand introduces the latest test management software technology for developing automated test systems more quickly and effectively. NI TestStand has features specially designed to develop LabWindows/CVI test systems fast, including a LabWindows/CVI flexible module adapter and NI TestStand user interface (UI) controls for LabWindows/CVI.

The LabWindows/CVI flexible module adapter ensures maximum return on your software development investment by increasing code reusability. You now can call functions within any LabWindows/CVI .c, .obj, .lib, or .dll file regardless of the function prototype. The LabWindows/CVI flexible module adapter has also been updated to improve parameter visualization when you configure a module in NI TestStand. These improvements substantially reduce development times and eliminate unnecessary programming.

Figure 7. With the new LabWindows/CVI flexible module adapter, you can call functions within any LabWindows/CVI file from NI TestStand, regardless of the function prototype.

View the NI TestStand home page.

Conclusion

The proven LabWindows/CVI development environment can make your ANSI C application development more productive with integrated workspace and development tool enhancements, more robust hardware functionality, real-time connectivity capabilities, advanced data management tools, and tight test management integration.

• Evaluate LabWindows/CVI
• See the Latest LabWindows/CVI Pricing Information
• View the LabWindows/CVI Home Page

The mark LabWindows is used under a license from Microsoft Corporation. Windows is a registered trademark of Microsoft Corporation in the United States and other countries.

Linux® is the registered trademark of Linus Torvalds in the U.S. and other countries.

 

Reader Comments | Submit a comment »