Commentary: August 2006

By Jeff Kodosky, National Instruments

In the 1980s, the spreadsheet put the power and flexibility of the computer squarely in the hands of the user. Spreadsheets enabled accountants with no programming experience to create sophisticated  what-if financial analyses. From its conception, National Instruments’ LabVIEW, which celebrates its 20th anniversary this year, has been designed to do for engineers and scientists what spreadsheets did for accountants: simplify and revolutionize the automation of complex measurement and control systems.

The typical block diagrams engineers draw to describe a system are appropriate for documentation, but they do not have rigorous semantics to specify the behavior of a program. Flow charts are well known but difficult to understand without reading the text instructions in the boxes. Data flow diagrams have many nice properties, but become complicated when representing iterative algorithms essential for measurement applications.

Jeff Kodosky, National Instruments

This brings us to the graphical approach of adding a box to represent a loop in a data flow diagram. Radically different from traditional text-based approaches, this intuitive data-flow representation was at the heart of LabVIEW 1.0 running on a Macintosh and is central to LabVIEW today running on Mac, Windows, or Linux platforms.

Two fundamental concepts—the front panel and block diagrams—characterize LabVIEW. Engineers create user interfaces by dragging and dropping front-panel controls and indicators. You then wire these icons together like a block diagram, only as you do so LabVIEW helps you by writing fully editable code to describe the system being developed.

This higher-level programming of LabVIEW’s graphical development environment and its tight integration with I/O results in some remarkable applications. Christopher Atwood of Tristan Technologies, for example,  developed an application that monitors and diagnoses brain activity in infants at severe risk of developing cerebral palsy and epilepsy,  enabling doctors to intervene at an early stage. Without formal software development training, this single engineer and domain expert developed this advanced application in less than a year using LabVIEW and PXI hardware from National Instruments.

LabVIEW’s graphical programming paradigm also empowers our youngest students. For example, LabVIEW’s ease of use and its inherent application development abilities are key to NI’s collaboration with Lego on LEGO MINDSTORMS NXT, the next-generation robotics platform from Lego. MINDSTORMS NXT is based on LabVIEW, has intuitive icon-based programming that’s easy enough for kindergartners to leverage, and yet is extensible enough to create sophisticated robotics applications.

Engineers used LabVIEW 1.0 to control instruments using GPIB 20 years ago. Today, engineers use LabVIEW to implement real-time deterministic control applications, create custom hardware using FPGAs, develop communications and RF test systems, and design systems with embedded 32-bit processors. This is possible because of innovations in LabVIEW over the last 20 years like event structures for graphical event-driven programming and custom timing structures such as the timed loop. New diagram types, like state charts for representing static systems and transitions, as well as simulation diagrams to represent dynamic control systems, are yet more innovations that have simplified and changed the way engineers engineer with LabVIEW.

In the future, software that integrates design and test tools throughout product development shows great promise. Such integration, for example,  will enable designers to validate SPICE circuit simulations and mechanical designs with real-world measurements earlier in the product development process, greatly reducing costly redesigns in later development phases.

For the past 20 years design and test software development has focused on the specific needs of each phase of traditional product development. By striving to integrate the design and test worlds with the traditional phases of product development, tools such as LabVIEW will help engineers increase their productivity as they address the product development challenges of the next 20 years.

NI Fellow Jeff Kodosky cofounded National Instruments  with Dr. James Truchard and William Nowlin in 1976. Today, he is a respected mentor in the NI global R&D organization and continues to chart new directions for the LabVIEW graphical development platform. Send your comments about this article through e-mail by clicking here. Please reference “Software’s Role, August 2006” in your message