Design Scheme of General Electronic Product Function Test Platform

This paper analyzes the common problems in the current electronic product testing, and proposes a set of general electronic product functional testing platform, which is realized by COM technology. The so-called COM (Component Object Model) is a way to explain how to build dynamically interchangable components. This specification provides some binary and network standards that clients and components should follow to ensure interoperability. Through this standard, it will be possible to communicate between any two components regardless of whether they are in the same operating environment, whether the development language used is the same, and whether they are running on the same computer.
    1 Overview
    1.1 Background
    1.1.1 Current status
    Looking at the electronic product testing systems at home and abroad, the following problems generally exist:
    1) In the test task of the entire large-scale system, its unity and integrity lack system support;
    2) The testing process, flow, and standards are not uniform;
    3) The test module has poor versatility, portability, scalability, and maintainability;
    4) The quality of the testers varies;
    5) Different personnel test at different stages, and the degree of information exchange is different;
    6) The organization, storage, management, and use of test data are messy, and the degree of digitization is low;
    7) Poor data validity, reliability, traceability, sharing, and ability to analyze data;
    8) The data has insufficient support for generation, approval, release, change, and circulation;
    9) The production efficiency is low, leading to higher unit production costs.
    The occurrence of the above problems will reduce the efficiency of electronic product development, resulting in uncontrollable project progress and increasing the difficulty of product quality assurance.
    1.1.2 Future Development
    The new generation of electronic product testing systems will develop in the direction of generalization, standardization, combination and networking. Combined with the development of modern automatic testing technology, the testing technology of modern electronic product testing systems will surely produce profound changes, which are mainly manifested in four aspects:
    1) The overall test requires C3M integration. C3M refers to Control, Communication, Computer and Measurement;
    2) Using virtual instrument technology on the test platform;
    3) In test management, use network technology;
    4) In testing information processing, intelligent sensor information processing and multi-sensor information fusion technology are adopted.
    1.2 Significance
    Software automated testing
    Automated testing is a process of transforming human-driven testing behaviors into machine execution. Usually, after the test case is designed and passed the review, the tester executes the test step by step according to the procedures described in the test case, and compares the actual result with the expected result. In this process, in order to save manpower, time or hardware resources and improve test efficiency, the concept of automated testing was introduced. In addition, on the basis of fully considering the current electronic product testing problems, combined with the development characteristics of the new generation of electronic product testing systems, we have developed an electronic product functional testing software platform (Electronic Test Platform, hereinafter referred to as ETP) to build general electronic products. The product function test platform provides a good solution. Figure 1 is a schematic diagram of a general electronic product functional test system.




    2. Introduction to ATLAS
    2.1 ATLAS features
    ATLAS (Abbreviated Test Language for All Systems) is a common standard test language widely used in the military and electronic testing fields. The test program written in this language does not depend on any special system under test, and it can be executed on the ATS.
    The Atlas client-side scripting framework is extensible, a 100% object-oriented JavaScript client-side scripting framework, allowing developers to easily build Ajax-style browser applications that have rich UI capabilities and can connect to Web Services. Using Atlas, developers can use DHTML, JavaScript, and XMLHTTP to write Web applications without having to master the details of these technologies.
    The Atlas client-side scripting framework can run on all modern browsers without the need for a web server. It does not require installation at all, as long as the correct script file is quoted on the page. Compared with general programming languages, this language has the following characteristics:
    1) Device independence, that is, no specific device appears in the ATLAS program written by the user, only test requirements;
    2) Signal correlation, test programs written by ATLAS programmers are all signal-oriented;
    3) Extensibility, allowing users to expand nouns, noun modifiers, and dimensions that are not in the ATLAS standard;
    4) Parallelism and timing function, some test statements in ATLAS need to be executed in parallel, and some statements need to be started at a specific moment;
    5) The grammar is close to natural language. The grammatical restrictions are not strict.
    ATLAS language can be divided into regular language part, signal and bus part from the semantics. The regular language part is similar to a complete procedural language, showing the characteristics of ATLAS language as a test language.
    2.2 ATLAS description
    The basic format of the ATLAS test statement is as follows:
    Action, (signal characteristics), signal type USING "virtual resource", signal modification parameters, CNX instrument end under test $
    Statement: APPLY, AC SIGNAL, VOLTAGE 115V, FREQ400HZ, CURRENT MAX 2A, CNX HI J32-3-A23$
    Meaning: Load a signal with a voltage of 115V, a frequency of 400Hz, and a current of 2A at the J32-3-A23$ point of the UUT.
    3.IVI introduction
    3.1 IVI system structure
    In order to achieve interchangeability, the IVI Foundation extracted the commonalities of similar instruments and made specifications. The eight types of instrument specifications that have been released are: oscilloscope (IviScope), digital multimeter (IviDmm), signal generator (IviF-Gen), DC power supply (IviDCPower), switch matrix/multiplexer (IviSwitch), power meter (IviPwrMeter), spectrum analyzer (IviS-pecAn) and radio frequency signal generator (IviRFSigGen), other types of instrument specifications will also be formulated and released. Each type of instrument has its own class driver (IVI Class Driver). Each type of driver contains various attributes and operating functions common to this type of instrument. When running, the driver controls the instrument by calling the corresponding function in the IVI Specific Driver of each instrument.
    The IVI system is developing rapidly. Advanced navigation systems need to integrate real-time traffic information, personal points of interest, and friend locations, etc., and even extend the car to the emerging Web 2.0 network era to bring consumers a new driving experience. To this end, it is necessary to establish an open and flexible platform that allows mobile devices and audio consoles to use the same architecture so that applications can be easily migrated between these two platforms. The primary considerations for building a new platform are connectivity, multimedia, speed to market, and total cost of ownership (TCO).
    Connectivity is extremely important. It refers to bringing Internet functions into the car as transparently as possible to allow consumers to easily access Web-based applications, data, and multimedia. Next-generation infotainment platforms must take into account power consumption, connectivity, graphics functions and performance, heat dissipation, and automotive ruggedness requirements. To this end, we need to adopt a new method that is completely different from the previous architecture and deployment of IVI systems.
    Next-generation IVI solutions must be more open, able to shorten time to market and support the integration of applications. In addition, the platform must reduce reliance on specific hardware configurations, make full use of the flexibility of software, and be able to easily upgrade with new applications. Currently in the field of IVI, many manufacturers are investing a lot of resources to develop almost the same basic functions. After adopting an open platform, these vendors can not only achieve more "reuse" at the basic operating system, driver and middleware level, but also significantly reduce their verification costs.
    Investments in platform building blocks such as operating systems, drivers, and middleware have enabled Intel to apply breakthrough functions to IVI solutions. Combined with the breakthrough features of Intel's 45nm process technology, Intel's "Atom" processor family vacated. In the next few years, Intel will continue to optimize the architecture and overall platform deployment plan to improve performance and reduce power consumption.
    Multimedia, consumer electronics, networking, and the automotive industry are rapidly converging. A feature-rich open platform will support the automotive industry to keep pace with the development of new consumer electronics and Internet technologies, and support users to carry and enjoy digital lifestyles everywhere.
    The application program can directly call the dedicated driver to control the instrument. But in order to realize the instrument interchange, the application program should call the class driver first, and the class driver checks the IVI configuration file to determine which special driver should be used. If the instrument in the system is replaced, only the IVI configuration file needs to be modified appropriately, and the application program does not need to be changed, thus realizing the universality of the test system.
    3.2 IVI driver characteristics
    1) Interchangeability. The interchangeability of IVI drivers brings us at least the following major benefits: a) Easy to use. The IvI drivers used all use a common interface, which is easy to understand, and no longer requires application developers to master the programming method of a particular instrument, so that system development has gained greater hardware independence. b) Reduce the maintenance and upgrade costs of the system. The IVI framework allows easy reuse and sharing of test codes between departments and equipment, and does not need to use the same type of instrument hardware.
    2) Simulation function. Each instrument-specific driver has a simulation function specifically for this type of instrument. These simulation functions enable engineers to use the simulation function of the IVI driver to develop and debug applications in the absence of real instruments. They can also use the analog-like driver provided by National Instruments to obtain more powerful simulation functions.
    3) State cache function. The IVI driver can save the current status of each property setting of the instrument. In the current test system, the bottleneck that affects the speed of software execution usually lies in the transmission rate of the instrument and the computer interface bus. This function of the IVI driver greatly reduces the communication between the instrument and the computer, thereby improving system performance.
    4) Open source code. Users can directly modify the source code of the IVI driver to optimize it or add functions.
    Get a lot of drivers. In addition to the IVI driver developed by the manufacturer, NI has also developed a large number of IVI drivers for various commonly used instruments. These programs are available on the NI website. In addition, NI also provides a toolkit for developing driver programs to simplify the user's IVI driver development process.
    4. Introduction to the test platform
    The software development platform used by the electronic product functional test platform is ETP, and its development and design are all carried out under the guidance of the concept of "flexible test" technology of Fanhua Measurement and Control. Whether to use this external force and how to use this force to standardize the enterprise testing process and improve the efficiency of specific testing activities is the topic to be discussed in this issue.
    At present, the research field of software test automation mainly focuses on the automation management of software testing process and the automation of dynamic testing (such as unit testing, functional testing and performance testing). In these two areas, compared with manual testing, the advantages of test automation are obvious. First of all, automated testing can improve test efficiency and enable testers to focus more on the establishment and development of new test modules, thereby increasing test coverage. This feature is of particular significance in functional testing and regression testing; in addition, the automated management of the testing process can make the organization's testing activities more procedural, which is in line with the idea of CMMI process improvement. According to a survey by OppenheimerFunds, in the three years around 2001, the return on investment achieved by the use of test automation methods was as high as 1500%.
    1) Introduction of ETP software platform
    Figure 2 is a schematic diagram of the ETP software architecture. The upper management software ETP adopts C++ programming. The underlying drive management module SEE (SignaI ExecuteEngine) uses LabVIEW programming. The upper management software realizes the function of test and measurement by calling SEE. The use of C++ development makes ETP more platform and expansive. The direct advantage is high operating efficiency. The overall framework of the software is:




    Configuration file (resource information) -> ETP engine -> report file (test result). In the bottom driver, we support various instruments such as NI series data acquisition cards, digital multimeters, waveform generators, and digital oscilloscopes.
    The ETP system has two main functions. One is to alarm the power loss, phase loss or exceeding the set threshold in the substation through the wireless network. The other is to collect various operating data of the substation and perform real-time monitoring. , It can realize functions such as fault analysis and electricity statistics, which is conducive to power dispatch and improves the quality of power supply.
    The ETP system is a completely domestically-made substation intelligent operation and maintenance system. It is independently developed by Zhejiang New Energy Technology Co., Ltd., and has obtained a number of national substations. Combined with its centralized intelligent monitoring and operation services for substations, it provides power outsourcing services for the society. After adopting this system and service, users can outsource the substation to a third party for maintenance, which can save labor and electricity costs, free up enough energy for the main business, and more effectively guarantee the power operation. Safety.
    2) Introduction of ETP conditioning module
    The main functions of each conditioning unit of the ETP conditioning module are as follows:
    ·The current design of the switch card is a 2×8 matrix switch, the input interface is a USB interface, and the output interface is an SMA interface. In addition, different topological structures can be combined according to actual needs. For example, two switch cards can be used to form a 2×16 or 4×8 matrix switch.
    ·DI conditioning card is a digital signal input conditioning board that supports multiple remote output types, optocoupler isolation, and Schmitt trigger functions.
    ·DO conditioning card is a digital signal output
The output conditioning board is to isolate the data of the digital J/O port of the NI card and then output it to the tested board, or control the relay output; at the same time, it can realize a variety of output types, test and control a variety of tested objects.
    ·CTV conditioning card is a current and voltage detection and conditioning board. It is designed as a power supply voltage and current detection circuit, which can measure industrial power supply voltage, current and power consumption. The measurement of voltage requires an external step-down device to drop the power supply voltage to within 100V before it can enter the CTV board.
    ·SAS conditioning card is a standard analog sensor signal conditioning board. The current detection is designed with a current transmission circuit. It can test temperature and pressure signals, convert current to standard current signal through current transmission, and then convert current to voltage and current to output standard voltage signal.
    ·CD conditioning card is an encoder conditioning board, which mainly realizes digital level conversion. For example, the commonly used ones are: the sine signal is converted to a square wave signal, and then the TTL level is output through the Schmitt trigger circuit. In addition, according to the actual situation, alternative differential to single-ended and filtering circuits are available.
    3) Test platform features
    a) Adaptability:
    ·Support the generation and measurement of nearly 40 kinds of signals and more than 100 kinds of parameters;
    · Test process automation. The typical single-step test time is ≤30ms, which meets the requirements of the production line for test efficiency;
    ·The interface adopts modular standard design to ensure that the interface is replaceable and easy to disassemble;
    ·Suitable for many instruments, such as NI series data acquisition cards, digital multimeters, waveform generators, digital oscilloscopes and other instruments; in addition, it can support traditional equipment such as PLC and independent instruments to ensure that the hardware system has a wide hardware foundation.
    b) Flexibility: The function and performance of the test system can be changed according to customer needs, test procedures and test parameters can be defined by oneself, and external equipment and test points can be set as needed.
    c) Extensibility: Test process compilation and hardware settings can be realized only through interface operations.
    d) Reliability: The software and hardware fully consider the exception handling mechanism, and can run for a long time and continuously without failure.
    5. Test platform application
    The project development process using the electronic product functional test platform is shown in Figure 3. We make software and hardware designs in real time through the test requirements provided by customers, and use ETP software to modify various configuration files. Simultaneously. Use the powerful TestStand engine function to edit the test process and perform the test, and the test task can be completed efficiently.

    The platform application features are as follows:
    ·Clear process;
    ·Easy to test;
    · Report specification.
    Platform application
    Name: A certain factory weather radar circuit board test project
    1) The test object of the weather radar circuit board test system of a certain factory is 13 circuit boards.
    a) Hardware configuration
    ·PXI-8106, DMM-4070, FGEN-5421, DSO-5112, PXI-6509, PXI-6713, PXI-8421;
    · Self-made signal conditioning chassis;
    · Self-made signal interface chassis.
    b) System composition
    The hardware of this system is composed of workbench, PXI subsystem, power supply (AC/DC power supply, synchronous machine, etc.) cabinet, test interface chassis, test fixture, etc., plus test software to form a complete test system.
    c) System characteristics
    ·Many types of test signals
    Mainly involved AC SIGNAL, DC SIGNAL, AM SIGNAL, PULSED DC, PULSED DC TRAIN, SQUARE WAVE, WAVEFORM, IMPEDANCE, LOGIC DATA, RS SERIALS COMMUNICATION, SERIALS COMM ADAPTAR, etc.
    ·The number of test points is particularly large
    With 13 circuit boards, the number of test points for a few boards is nearly 100 test points, and the number of test points for more boards is nearly 200 test points.
    2) The following is a comparison to illustrate the superiority of using the electronic product functional test platform to build a test system.
    ·Manual test method
    Through the use of portable traditional instruments, each circuit board is manually tested, and each test data is manually recorded. There are many disadvantages in using this method: on the one hand, the test efficiency is low, on the other hand, the test accuracy is difficult to guarantee, which will directly lead to the difficulty of controlling the development cycle and progress, and the entire system development quality system is difficult to establish.
    ·Automated testing method
    It is common to use various portable traditional instruments through the VXI bus mode, and then compile various instrument control panel software and test them one by one through various instrument buses, such as GPIB, CAN, and LAN. In addition, the test platform is not used, and the control, inheritance and maintenance of various instruments are very poor, which will also increase the development cost and prolong the development cycle.
    ·Automated testing method
    First of all, due to the use of PXI bus and the use of virtual instrument technology, our test system has flexibility, high stability, and strong versatility. In addition, by using our electronic product functional testing platform. Write the corresponding test package, including test steps and routing information configuration, and test data report format. Another major task is to design the conditioning module between UUT (board under test) and ATE (various instruments). This part of the work will further shorten the development cycle of the entire test system as the hardware conditioning module of our platform becomes more complete and mature.
    6. Concluding remarks
    ·Faced with the challenges of functional testing of electronic products, a suitable software and hardware system is required;
    ·PXI bus technology plays an important role in the general electronic product functional test platform;
    ·Based on LabVIEW, VC and TestStand software development environment, Fanhua Measurement & Control successfully developed the ETP platform;
    ·The hardware and test signal types supported by ETP can be further expanded;
    ·ETP has been successfully applied to actual projects.