Testing is a crucial and effective means of verifying whether the functions and performance of a test object meet usage requirements and to promptly identify problems. Generally speaking, testing technology and equipment are indispensable throughout the entire lifecycle of a product, from research and development to production and maintenance. They are essential tools in product development, quality assurance instruments in manufacturing, and key elements of the product maintenance and support system. Testing technology is a vital pillar for ensuring the "reliability, maintainability, and guaranteeability" of a product, serving as the technical means for testing, maintenance, and repair throughout its entire lifecycle. Testing instruments and testing systems composed of various instruments represent the ultimate manifestation of testing technology. With increasing testing demands and application development, especially with advancements in hardware and software technologies and testing methods, new technologies in the testing field have rapidly developed in recent years: such as the successive introduction and application of various new instrument buses, the continuous emergence of miniaturized, synthesized, and integrated instruments, the vigorous development of comprehensive and universal automated testing systems and integrated testing and diagnostic systems, and the continuous improvement and application of remote testing and maintenance diagnostic technologies, built-in self-testing technologies, and comprehensive testing and diagnostic software platform technologies. Based on industry application characteristics, testing instruments can be categorized into basic measuring instruments, synthetic instruments, microwave/millimeter-wave instruments, etc. To meet the needs of general testing, fault diagnosis, and integrated support systems, the industry has further developed and improved the basic measurement instrument series based on VXI/PXI/LXI instrument buses. This has been expanded and improved in areas such as chassis, controllers, high-speed data acquisition, high-end oscilloscopes, high-speed I/O, edge scanning, microwave instruments, and communication measurement instruments. The development of various forms of high-end and integrated instrument products has been strengthened, with emphasis on the standardization, networking, and application networking of instrument interfaces. The standardization of instrument drivers brought about by the introduction of the Interchangeable Virtual Instrument (IVI) standard has met the requirements for interoperability between instruments and provided a fundamental guarantee for the development and application of general-purpose test and diagnostic software platforms. In response to the development of next-generation radar, communication, electronic reconnaissance and electronic jamming, and precision guidance applications, and to meet the needs for simulation and high-precision measurement and analysis of dense, complex, and variable electromagnetic environments, related technologies for synthetic instruments and microwave/millimeter-wave test instruments have developed rapidly. For example, the emergence of wider-frequency agile and nonlinear, multi-port, and high-power test instrument technologies and instruments has enabled more parameter integration, modularization, and integrated testing. Research and application of testing technologies for radio and optical communication networks, infrared testing technologies, and software-defined radio technologies have also progressed rapidly. A test system is inseparable from the test bus, which itself becomes a major component of the test system. Based on differences in bus structure, function, and nature, test buses can be divided into internal buses and external buses. The two most popular internal test buses in the industry are VXI and PXI, which were developed based on VME and PCI computer buses, respectively. Although they have defined many different mounting structures and bus definitions, due to the de facto standards used, the current majority of structures are: VXI uses the C-size, while PXI uses the A-size. In the latest version, VXI (V3.0) achieves a bus speed of 160MB/s, while PXI boasts an even faster bus speed of up to 528MB/s. Another development in PXI's speed enhancement is its support for PCI Express, sometimes referred to as the PXIE bus. This integrates the PCI Express bus onto the PXI bus backplane to meet the high-speed data transfer requirements of certain instrument modules. In terms of application, both buses have seen significant development in the testing field. VXI defines more stringent requirements for clock speeds, power supplies, chassis, and electromagnetic compatibility, thus primarily finding applications in high-end testing. PXI, on the other hand, has seen rapid growth in applications demanding miniaturization and high-speed data transfer between instruments. Another high-speed bus development is the introduction and application of the ATCA (Advanced TCA) bus, supporting interface speeds up to 40Gb/s. Domestic instrument manufacturers, represented by aerospace measurement and control companies, have fully mastered the development technology of various VXI/PXI bus modular test instruments and formed a series of VXI/PXI bus basic measurement instrument off-the-shelf products. The specifications of most of these products are comparable to, and in some cases even surpass, those of foreign products, while also meeting a wider range of usage environment requirements. External buses include GPIB, USB, 1394, and LXI, among others. Currently, USB and LXI buses are the most actively developed and applied. In miniaturized, portable, or laboratory applications, USB-interface instrument systems are experiencing rapid growth. The LXI bus, developed based on the widely used Ethernet, is considered the first truly meaningful external instrument bus. It is divided into three levels: A, B, and C, with level A having the highest requirements. It can meet the functional requirements of precise clock synchronization and synchronous triggering, and has unique application potential in distributed and large-scale test systems, opening up new possibilities for test technology applications. With the development of new technologies worldwide, the application of information technology and information equipment has become a key way to improve equipment capabilities. Whether in civilian or military fields, land, sea, and air equipment, communication systems, automated production facilities, etc., are constantly increasing their functions such as electromagnetic detection, automated control, data analysis, data transmission, and network communication, and the electronic equipment they support is also constantly increasing. In order to ensure the normal operation of equipment, the testing and fault diagnosis of these advanced and complex electronic devices are particularly important. Faced with such an increasingly heavy and complex testing and diagnosis task, for many years, while focusing on breakthroughs in individual testing technologies, the industry has strived to make testing equipment automated, universal, and integrated to meet the comprehensive testing capabilities of general analog, digital, radio frequency, and optoelectronic systems. The characteristics of a universal test system are reflected in the universality of test instruments, software platforms, and interface adapters. In the development of universalization and integration based on Automated Test Systems (ATS), previous decentralized investment and management resulted in a wide variety of ATS types, inconsistent system architectures, and specialized hardware and software interfaces, making true universalization difficult to achieve. To achieve universalization and integration of test equipment, centralized management and planning of ATS are necessary. Taking the United States as an example, one measure they took was to incorporate ATS into the Department of Defense's Joint Technology Architecture to strengthen ATS standardization; another measure was to launch the Next Generation Test Program (NxTest) to unify the ATS system architecture across the three services. The system architecture aims to achieve the generalization and integration of testing equipment. By using the IEEE-1226 standard as the main information framework, it enables information resource sharing and interaction within the testing system, between testing systems, and between the testing process and the external environment (including all stages from product design and production to maintenance). This allows for shared TPS and ATS, shared diagnostic infrastructure, improved TPS development environment, and easier TPS portability. Simultaneously, by incorporating the IEEE-1232 standard, the diagnostic reasoning system becomes compatible with each other and independent of the testing process, achieving portable, reusable, and shareable test diagnostic knowledge. The goal of these measures is to reduce testing equipment hardware by two-thirds, engineering costs by two-thirds, and TPS development time and costs by 50-70%. The final results are significant, greatly reducing the scale and investment of testing equipment. Following the development during the "15th Five-Year Plan" period, some domestic professional measurement and control manufacturers have fully utilized mature modular instrument technology, standard bus technology, general software platform technology, and automated testing system technology to develop generalized and integrated testing system equipment that meets military and civilian needs. These systems have been successfully applied in aerospace, aviation, shipbuilding, and vehicle testing fields. This research aims to standardize an open architecture for multi-level automated testing, absorbing the design principles of the NxTest architecture to meet the requirements of equipment lifecycle testing and cross-platform testing. It also seeks to achieve resource sharing, interconnection, interchangeability, interoperability, scalability, and generalized testing needs such as vertical integration testing. By resolving issues related to unified specifications and standards, and ensuring ATS compatibility across software platforms, system interfaces, and installation structures, resource utilization can be further improved, achieving more generalized and comprehensive testing objectives. Fault diagnosis and integrated support technology testing and diagnosis involve acquiring various parameters of the tested object, understanding its characteristics and functions, analyzing and evaluating them, determining its working or performance status in a timely and accurate manner, and isolating internal faults. This provides a basis for maintenance judgments. Fault diagnosis represents the highest level of testing. Through system-level and board-level fault diagnosis technologies, faults can be located at the component, board, or even individual device level, enabling accurate location and timely repair, thereby significantly reducing the mean time to repair (MTBL) of systems or equipment. The integrated support technology system includes reliability technology, testing technology, and field maintenance technology. Reliability, testability, and maintainability are all closely related to the product design process. Testing and diagnostics provide the fundamental data for reliability modeling, reliability analysis, and maintainability modeling. Furthermore, reliability allocation, reliability prediction, and maintainability prediction place demands on testing and diagnostics. Therefore, managing the relationships between these aspects is crucial. To meet the comprehensive assurance needs throughout the product lifecycle, some organizations have transitioned from qualitative to quantitative analysis in reliability, testability, and maintainability design, as well as in testing and evaluation technologies. They have launched numerous supportability design analysis and evaluation tools, and have achieved the organic integration of supportability and performance in the equipment development process based on digital design platforms. They have also achieved the integration of various design characteristics based on multidisciplinary design optimization technologies. In terms of maintenance technology, information technology, advanced sensor technology, automatic testing technology, fault diagnosis and prediction technology, and artificial intelligence technology are used to develop electronic maintenance, virtual maintenance, and simulation technologies for comprehensive detection, prediction, and evaluation, thereby improving the speed and accuracy of maintenance. In terms of testing and diagnostic technologies, integrated testing and fault diagnosis technologies have been further developed and improved. A standardized architecture for integrated diagnostic and maintenance support systems has been established, compatible with the IEEE-1445 standard. More effective fault modeling, reasoning diagnostic methods, testing, diagnostic, and information fusion technologies are applied, providing technical means for system-level, board-level, and chip-level fault diagnosis, and offering more comprehensive technical and product support for equipment integrated maintenance support. With the development of information technology, the latest theories of fuzzy theory, neural networks, genetic algorithms, and wavelet transforms have been applied to the field of fault diagnosis, achieving certain results. In addition, fuzzy fault trees, fuzzy neural networks, fuzzy rule-based expert systems, and genetic algorithm-based diagnostic methods are all under in-depth research. Regarding maintenance equipment products, many organizations have developed and applied board-level and system-level integrated fault diagnosis system products using expert systems and artificial intelligence methods. Typical examples include Teradyne's LASER system, ATEC Series6 from France Aerospace, ARIS2000 from Israel, and the "Hua Tuo Electronic Clinic" HTEDS8000 system from Aerospace Measurement and Control Company. Due to their high levels of intelligence, digitalization, and bus-based characteristics, the new generation of equipment is seeing traditional external testing and diagnostics gradually replaced by internal BIT (Block In-Test) functions, a significant trend in current testing technology development. BIT technology can be traced back to the early 1950s, when the United States began researching it and successfully equipped its airborne radar with conventional BIT devices by the late 1950s. This was subsequently applied to its F/A-18 fighter jet. To improve BIT performance, foreign countries have integrated artificial intelligence, computer technology, and semiconductor technology into various BIT levels, including components, circuit boards, and systems. In the late 1980s, a new BIT technology based on boundary scan technology emerged and gradually became the main testing and test design technology for new avionics equipment, successfully applied in systems such as the F-22, RAH-66, and Boeing 777. This new BIT technology is primarily based on the IEEE-1149 series of standards, which mainly define board-level and module-level networked test and maintenance buses, enabling board-level and subsystem-level (unit device) BIT for digital and analog circuits. Currently, some instrument companies (such as NI and Corelis) have developed development tools, software, and systems that conform to the IEEE Std 1149 standard. Many domestic research institutions are also conducting work in this area, achieving certain results and launching some hardware and software products. In conclusion, the needs and applications in the testing field are extremely broad. The technologies used range from analog to digital, from low frequency to high frequency/microwave, from testing to diagnostics, and from maintenance to support. All aspects are developing rapidly. The professional terms we see, such as instrument, virtual instrument, testing, virtual testing, virtual experiment, diagnostics and maintenance, prediction and evaluation, BIT, etc., are all carriers of new technologies and applications in the testing field. We are pleased to see that the relevant government departments, research institutes, and manufacturers in the domestic testing field attach great importance to the planning and innovation of testing technology development, which will undoubtedly greatly promote the improvement of testing technology and testing equipment.