Overview Welcome to the Developer's Guide to Designing the Next Generation of Automated Test Systems. This guide includes a series of white papers to help you reduce costs, increase throughput, and scale to future needs when developing test systems. This white paper describes the differences between modular instrumentation platforms and traditional instrumentation platforms. To download the complete developer's guide (120 pages), please visit ni.com/automatedtest/zhs. [b]Introduction: Design Challenges of Automated Test Systems[/b] Test managers and engineers use automated test systems across a variety of application areas—from design verification and end-product testing to equipment maintenance and diagnostics—to ensure the quality and reliability of products delivered to customers. They use automated test systems to perform simple "pass" or "fail" tests, or to perform a full suite of product feature tests. Automated test systems have rapidly become an important part of the product development process due to the rising costs of product defect detection late in the design cycle. This article, "Designing the Next Generation of Automated Tests," describes some of the challenges that are forcing engineering teams to reduce testing costs and time. This article also provides insightful perspectives on how test managers and engineers can overcome these challenges by building modular, software-defined test systems. This type of testing system significantly increases throughput and flexibility while reducing overall costs. Today's test engineers face a series of new pressures. Their product development environment includes: more complex product designs than previous generations; shorter development cycles to remain competitive and meet customer requirements; higher product testing costs and smaller budgets; and increasing design complexity. The most obvious trend in test measurement today is the increasing complexity of devices. For example, the consumer electronics, communications, and semiconductor industries continuously demand the integration of digital imaging/video, high-fidelity audio, wireless communication, and internet connectivity into a single product. Even in automobiles, complex automotive entertainment and information systems, safety and early warning systems, and control electronics on the body and engine are integrated. Test system design not only needs to be flexible enough to support extensive testing of different product models but also needs to be upgradable to provide more test points for new testing capabilities. Shorter Product Development Cycles Due to the competitive nature of continuously improving new products and technologies and achieving first-mover advantage, design and test engineering teams must constantly shorten product development cycles. To this end, engineering teams must design new testing strategies to reduce testing time and improve testing efficiency from design to production. Increasing Testing Costs and Decreasing Testing Budgets To address the challenges of increasing device complexity, shorter development cycles, and reduced budgets, test managers and engineers are forced to abandon traditional test design strategies based on conventional box-type instruments or bulky proprietary ATE systems. These standalone instruments lack the flexibility necessary for software processing, and their user interfaces are vendor-defined, requiring firmware updates from the vendor. This makes it difficult to perform tests not defined in the instrument firmware or to test new standards; or to modify the system when requirements change. Because these devices were originally designed as standalone instruments, they lack necessary integration capabilities, such as data streaming and synchronization. Proprietary ATE systems (such as highly integrated product chip testers) can provide the required performance, but they are extremely expensive and may render engineering teams obsolete, leading to premature system redesign. In response, test managers and engineers are implementing modular, software-defined test architectures. This architecture, based on widely adopted industry standards, offers: Greater test system flexibility: Scalable to multiple applications, business units, and product stages. High-performance architecture: Significantly increases test system throughput and provides close connectivity and integration with different instrument manufacturers, including the generation and analysis of precision DC signals, high-speed analog and digital signals, and RF signals. Lower test system investment: Reduces initial capital investment and maintenance costs while increasing equipment utilization across various testing requirements. Longer test system lifespan: Based on widely adopted industry standards, it allows for technology upgrades to improve performance and meet future testing needs. NI, as a leader in automated test, is committed to providing product engineers with the hardware and software needed to design next-generation automated test systems. This in-depth developer guide contains the information needed to design next-generation automated test system architectures. The introduction describes a test system architecture as shown in Figure 2, providing engineers with strategies to address challenges such as increasing device complexity, shorter development cycles, and decreasing budgets. Increasing test costs and decreasing test budgets Adding device functionality often leads to more expensive and time-consuming test processes. However, the cost of building each feature is decreasing, forcing engineering departments to reduce costs and budgets, as shown in Figure 1. Engineers must improve testing strategies to reduce total costs by increasing the throughput of the test system, reducing maintenance and upgrade costs, and minimizing required capital investment. Hierarchy Five: Automated Test System Management Software Automated test systems need to implement various tasks and measurement functions: some of these tasks and functions are device-under-test (DUT) specific, while others are common to all DUTs. To minimize maintenance costs and ensure the lifespan of the test system, it is crucial to implement a testing strategy that separates DUT-level tasks from system-level tasks. This allows engineers to quickly reuse, maintain, and modify test programs (or modules) to meet specific testing requirements throughout the development cycle. In all test systems, there are different operations depending on the DUT, as well as operations common to all DUTs, such as system-level tasks. For each device, there are different operations: instrument configuration, measurement, data acquisition, result analysis, calibration, and test modules. For each device, there are common operations: user interface, user management, DUT tracking, test process control, result storage, and test reports. Some companies have written their own test executors and allocated valuable engineering resources to develop test management software from scratch. This often leads to decreased productivity and long resource consumption for software maintenance. To maximize productivity, engineering teams should utilize commercially available test management software, such as NI TestStand software, to reduce the development of common operations for each device. By using this software, engineers can focus on developing device-specific operations. For more information, please refer to the white paper "Developing a Modular Software Architecture". Layer Four: Application Development Software. In the test system architecture, application development environments (ADEs), such as NI's LabVIEW and LabWindows/CVI, play a crucial role. Using these tools, test system developers can communicate with a wide variety of instruments, integrate measurements, display information, connect to other applications, and more. An ideal ADE (Application Controller) for developing test and measurement applications needs to provide a range of application requirements, including ease of use, high compilation performance, integration with various I/O systems, and programming flexibility. Ease of use is not just about how quickly you can get started and use it. With an easy-to-use ADE, developers can easily integrate processing routines and various measurement devices, create complex user interfaces, deploy and maintain applications, and modify applications as product design improves or the system needs to be expanded. For more information, please refer to the white paper "Choosing the Right Software Application Development Environment". Layer 3: Measurement and Control Services. Measurement and control services provide crucial connectivity, system configuration, and diagnostic tools for various hardware resources in the system. For example, NI Measurement and Automation Explorer (MAX) can automatically detect hardware resources, including data acquisition and signal conditioning hardware; GPIB, USB, and LAN-controlled instruments; PXI systems, VXI devices; modular instruments, etc., allowing developers to configure them in one place. Integrated diagnostic testing ensures proper device functionality, while test panels provide developers with a quick way to check hardware capabilities before programming. Measurement and Control services also provide integration with the application development software layer via application programming interfaces (APIs), allowing developers to easily program their devices. In fact, the components of this service software—hardware drivers, APIs, and configuration managers—must be seamlessly integrated into the ADE to maximize performance, improve development productivity, and reduce total maintenance costs. For more information, please refer to the white papers *Hybrid Systems: Integrating Your Multi-Vendor, Multi-Platform Test Equipment* and *Instrument Bus Performance: Making Sense of Competing Bus Technologies for Instrument Control*. Architecture Level 1: Measurement and Device I/O Fundamentally, there are currently two types of instrument architectures—traditional instruments and virtual instruments. Figure 4 illustrates the similarities between these two architectures. Both feature measurement hardware, chassis, power supply, bus, processor, operating system, and user interface. From a hardware perspective, the most obvious difference lies in how the components are organized. Traditional or standalone instruments cram all components into a single enclosure. Measurement capabilities, analysis, display, and instrument control are all vendor-defined. In contrast, modular, software-defined virtual instruments integrate common measurement hardware, allowing users to define their own measurements and user interfaces within the software, in addition to standard functions. Using a modular approach, engineers can define the measurement capabilities of a test system and build scalable systems to meet future needs. Through this modular, software-defined approach, users can perform custom measurements, measure for emerging standards, or modify the system when requirements change (e.g., adding instruments, channels, or new measurements). This flexible, user-defined software combined with scalable hardware is at the heart of modular instruments. For more information, please refer to the white papers "Understanding a Modular Instrumentation System for Automated Test" and "PXI: The Industry Standard Platform for Instrumentation." In conclusion, the increasing complexity, shorter development cycles, and lower budgets of designing next-generation automated test systems have given engineering teams the opportunity to re-evaluate existing automated test strategies and find ways to improve efficiency and reduce costs. When designing next-generation automated test systems, it is crucial to incorporate strategies that increase system flexibility, deliver higher measurement and throughput performance, reduce test system costs, and extend lifespan. Modular, software-defined automated test systems overcome the shortcomings of previous solutions based on stand-alone instruments or costly proprietary ATE systems. Modular hardware platforms, based on widely adopted industry-standard platforms such as PXI, allow engineers to develop scalable test systems that tightly integrate functionality from various instrument vendors. Furthermore, it allows engineering teams to integrate existing equipment investments to reduce initial implementation costs. Leveraging the latest PC technologies, such as multi-core processors and the PCI Express bus, software-defined measurements in next-generation automated test systems can significantly improve throughput performance and are scalable to meet the needs of different product stages and business units. Many companies have implemented modular software-defined test system strategies and demonstrated the return on their investment. For example, Microsoft designed a test system for the Xbox 360 controller based on NI LabVIEW and PXI modular instruments that is twice as fast as its predecessor. The US Air Force developed test architectures to support their advanced fighter jets. Leveraging a PC-based software and hardware architecture, they reduced costs and halved the size of their test system. Sanmina-SCI built an FDA-approved pharmaceutical device test system using NI TestStand and PXI products, exceeding their requirement to test 83,000 devices per week and exceeding their throughput requirement by 95%. NI Products and White Papers: As a leader in automated test, NI is committed to providing product engineers with the hardware and software needed to design next-generation automated test systems. Software: • NI TestStand test management framework • LabVIEW graphical programming language • LabVIEW SignalExpress interactive measurement software Hardware: • Modular instruments (oscilloscopes, multimeters, RF modules, switches, etc.) • Multifunctional data acquisition • PXI system components (chassis and controller) • Instrument control (GPIB bus, USB bus, and LAN) Technical White Papers: NI provides the "Designing Next-Generation Automated Test Systems Developer's Guide." This guide compiles various white papers to help develop test systems that reduce costs, increase test throughput, and scale to meet future needs. To download the complete developer guide (120 pages), please visit ni.com/automatedtest/zhs. Editor: He Shiping