Personal ATE -- Bringing ATE Technologies to the Desktop

ATE Technology on Your Desktop

For many years, high-volume manufacturing and complex military and aerospace test applications have required high-end automated test equipment (ATE). ATE systems, which historically have been built with proprietary hardware and software, required many months to develop and build. In addition, because systems were generally designed for a specific test application, they lacked scalability for other applications. Despite high cost and certain limitations, many applications have continued to require dedicated ATE to achieve throughput and coverage requirements. For such applications, the cost and time required to build these systems has been accepted.

As technology has continued to evolve, however, commercial technologies have developed that now parallel and often eclipse the capabilities of dedicated, proprietary systems. National Instruments has been at the forefront of this revolution, brining increasingly sophisticated hardware and software technologies to bear on automated testing applications. NI has built a comprehensive hardware and software architecture that brings capabilities once confined to very expensive, proprietary systems, to applications ranging from design verification testing to highly automated manufacturing testing. Just as computers that once filled entire rooms have shrunk in size with steadily increasing capability, sophisticated ATE is now available for desktop use with the cost, flexibility, and performance demanded by a large number of engineers in research, design, and manufacturing.

Proprietary ATE

In the past, engineers requiring a high-end automated test system had few choices – they typically purchased a tester from a test-systems integrator built largely on proprietary hardware and software. These systems took months to develop, cost hundreds of thousands of dollars, and left the user highly dependent on the vendor. An example of typical proprietary ATE is represented in Figure 1.

In 1907, Henry Ford made bold claims about his plans for the automotive industry. At the time, Ford was a relatively small player among over 30 manufacturers. Ford claimed of his automobile:

"It will be so low in price that no man making a good salary will be unable to own one -- the horse will disappear from our highways, and the automobile will be taken for granted."

Of course, Ford did achieve his goal, and he did it by changing the way automobiles were manufactured. Ford’s disruptive technology of mass production completely changed the cost structure of the automotive industry and significantly broadened the market for automobiles. He realized that nearly everyone could benefit from having a car if they could afford and successfully use it.

Proprietary ATE is similar to the pre-1907 automobiles. Certainly many applications still require high-end, custom-made ATE, just as race cars and exotic sports cars are still made by hand as in 1907. The vast majority of the world, however, requires more flexible, less expensive test solutions that take advantage of commercially available technology. National Instruments has been at the forefront of harnessing commercial technology to democratize ATE, making it available to a very broad set of scientists and engineers for automated testing.


GPIB Standardizes Connectivity to Instrumentation
In 1975, IEEE Standard 488-1975 defined the general-purpose interface bus (GPIB), which still serves today as the standardized interface between PCs and stand-alone instrumentation. Prior to GPIB, automating test instrumentation proved to be a daunting task. It was necessary to build expensive custom hardware and low-level software for each instrument that needed to be automated.

Because GPIB became a broadly used standard, many thousands of engineers have benefited from the availability and ease of use of GPIB. Today, an engineer can connect an instrument to a computer in very little time, using standard software to begin communicating with the instrument immediately.

LabVIEW Revolutionizes Instrument Control
While GPIB created a standard hardware and software methodology for communicating with instruments, creating automated test routines still required extensive programming. In 1986, National Instruments introduced LabVIEW, bringing a new level of productivity to software used for automating instrumentation. Just as the spreadsheet introduced a new paradigm to financial applications, LabVIEW brought a new graphical paradigm to scientists and engineers for test and measurement.

With LabVIEW, creating an automated test system no longer required a sophisticated computer scientist; rather, the expert in the device or technology under test could use their expertise in the application to build a test system.

As LabVIEW evolved, it grew to encompass more functionality than just traditional instrument control. Today, LabVIEW is used extensively to create applications for data acquisition, image processing, motion control, and factory automation. With these broad capabilities of LabVIEW, ATE systems have expanded to encompass what were once considered peripheral functions, such as visual inspection, motion control, and enterprise integration.

VXI Introduces Modular Instrumentation
In 1987, the introduction of VXI defined a modular platform for instrumentation. The goal of VXI was to provide a format where an engineer could build a test system by selecting the measurement modules needed from different vendors to create a highly customized, scalable test system. But VXI maintained a software architecture much like GPIB, where each vendor defined the functions and communication paradigm for each module. Thus, although VXI delivered a modular hardware framework, the software for each module resided in a silo with no interaction among modules and very little commonality in programming. The result was that VXI never achieved broad industry acceptance as a modular hardware platform but instead was confined to high-end applications, especially vendors of large expensive ATE.

PXI Combines Commercial Technology with ATE
In 1997, the introduction of PXI (PCI eXtensions for Instrumentation) combined the latest commercial hardware and software technologies with concepts and technologies derived from ATE, such as sophisticated timing and triggering for high-performance measurements. By exploiting commercial PC and digitizer technologies, PXI provides the high performance of proprietary ATE, but at a much lower cost.

Just as other electronics industries have been able to deliver order-of-magnitude advances in performance in smaller and smaller packages, PXI provides performance exceeding VXI and GPIB in considerably less space. PXI truly makes it possible to have sophisticated ATE on a desktop.

Further, PXI provides a diverse set of measurement and control capabilities, including vision, motion, and real-time control, providing important functionality integrated into the same platform as the traditional electrical measurements.
The small size, low cost, and flexibility of PXI make it applicable to a wide set of applications, including research, desktop ATE, field measurement, and high-end manufacturing test

Measurement and Control Services Efficiently Integrate Test Hardware with Test Software
To fully deliver on the promise of PXI to provide a tightly integrated measurement and control platform, it is essential to have a software architecture that defines a common interface to different types of hardware. This software layer, which resides between the test development environments and the hardware, is called Measurement and Control Services. Measurement and Control Services include driver engines, flexible, high-level application programming interfaces (APIs), and a configuration manager.
In the past, the interface between hardware and software was a challenging development task, typically requiring extensive knowledge of the hardware, low-level programming, and even real-time system development. NI Measurement and Control Services provides a high degree of integration among modules and a uniform configuration and programming model. It is essential in delivering the productivity and ease of use required to make creating ATE accessible to a broad set of engineers

TestStand Brings Test Management to the Desktop
All proprietary ATE has some type of test management software. The functions of this software include:

• Organizing a set of test routines
• Sequencing, branching, and looping through tests
• Collecting and organizing test results
• Providing a consistent user interface to different tests

Because this software is typically created for a single type of tester, however, it lacks flexibility and scalability. Further, it is not widely used (each ATE vendor sells only dozens or maybe hundreds of systems each year) and therefore is not adopted by a large set of users, integrators, and third parties.

In 1998, National Instruments, after many years of working with key customers and integrators, introduced TestStand, a test management environment that provided the key features of software typically found on proprietary ATE. TestStand brought an important ATE technology – test management – to a very broad set of users. Anyone doing automated testing who wanted to organize, execute, and record information from a set of test routines could use TestStand. Consequently, the user base became very broad, and today TestStand is used by a large set of users, integrators, and third parties.

The tight integration of TestStand with development environments such as LabVIEW make it a very flexible tool for creating automated tests. Together, TestStand and LabVIEW provide an optimal test environment not just for the manufacturing floor, but also for desktop applications.

Switch Executive Provides Sophisticated Switch Management and Routing
The latest ATE technology to democratize ATE is NI Switch Executive. Switch management systems have long been used on ATE systems to control routing and route management of switch matrices. This functionality is essential to use medium-to-large switch matrices productively and manage switch routing, especially among multiple products under test.

NI Switch Executive is a configuration tool for managing and defining routes for NI and third-party switches. In Switch Executive, the engineer defines a set of routes for a test or set of tests, which can then be used easily in test programs. Switch Executive tightly integrates with LabVIEW and TestStand to provide intuitive switch management directly from the development environment or test management system.

Personal ATE for Manufacturing Test Engineers

Manufacturing test systems have been the primary user of proprietary ATE systems for many years. As devices have increased in sophistication, though, the cost of the systems to test these devices has escalated rapidly. As a result, the cost of testing has become a proportionally larger percentage of the manufacturing cost of many products. Figure 3 shows this trend for integrated circuit fabrication. Although the manufacturing cost per transistor has dropped by a factor of 10 in the 1990s, testing cost per transistor has actually increased!


Due to this trend, there is increasing focus on lowering the cost of testing for manufacturing applications. Today’s commercial technologies provide a far lower cost of testing to end-users and test-system integrators by increasing both their test-system performance and development productivity while significantly lowering the overall cost of ownership.

Personal ATE for Design Engineers

A design engineer’s job is to design products. Testing product functionality and performance, while a necessary part of the iterative design process, is probably not the favorite part of his/her job. For design engineers, personal ATE means having sophisticated ATE technologies at your desktop. Taking full advantage of commercial technologies results in an automated test system that can fit into the needs of design engineers by providing:

• Low system cost
• Reduced test development time
• System flexibility and scalability
• Small size

With powerful ATE technology available on your desktop, you can spend less time on test and more time designing your products.

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