CN204789908U - Circuit board automatic test system based on labVIEW - Google Patents

Abstract

Circuit board automatic test system based on labVIEW, it relates to circuit board test system. The utility model discloses a for solve circuit board test system among the prior art exist pore over low, the reliability is poor, visual less than the problem. The utility model discloses a host computer, data collection card, the circuit board awaits measuring, reference circuit board and a plurality of elasticity probe, it is equipped with a plurality of test points on the circuit board to await measuring, be equipped with a plurality of reference points on the reference circuit board, the one end of elasticity probe is fixed on the reference point of reference circuit board, the other end of elasticity probe and the test point contact of the circuit board that awaits measuring, the reference point of reference circuit board passes through the wire and is connected with data collection card's input foundation, data collection card's output passes through the USB interface and is connected with host computer foundation. The utility model discloses a carry out the high speed to the circuit board and test reliably, improvement digital circuit's quality and reliability.

Description

Circuit Board Automatic Testing System Based on LabVIEW

technical field

The utility model relates to a circuit board testing system, in particular to a circuit board automatic testing system based on LabVIEW, and belongs to the technical field of circuit board testing.

Background technique

With the rapid development of science and technology, especially the wide application of digital technology and various VLSIs, the structure of electronic equipment is becoming more and more complex, the functions are becoming more and more perfect, and the degree of automation is getting higher and higher. Although the performance of the electronic system has been improved, many problems such as complex test process and long test time have arisen in the testing and maintenance support, which seriously affect the production cycle, integrity and life cycle of electronic equipment.

The cost of digital circuit system testing using traditional experimental equipment and methods is high and consumes a lot of manpower and material resources. For example, the traditional method based on signal analysis uses voltmeters, ammeters, oscilloscopes, logic analyzers and other equipment to test digital circuits. The process is very complicated and the reliability is low. Energy, the correctness of test results are greatly affected by test equipment, environmental factors and human factors.

Testing is a basic method and means for people to obtain qualitative or quantitative functional information and performance information in a controlled state. During the circuit design and manufacturing process, at least two tests are required: one is at the chip level to eliminate faulty chips; the other is at the product level to ensure that the functions and performance of the system are intact. During the use of the circuit, a complete round of testing can determine the current working state of the circuit and determine whether fault diagnosis is required.

Automatic test system refers to those systems that use computer control to realize automated testing. It is a general term for systems that can automatically complete incentives, measurements, data processing, and display or output test results. This type of system is usually formed on the basis of a standard measurement and control system or a common bus, and has many characteristics such as high speed, high precision, multi-function, multi-parameter and wide measurement range.

Especially for the national defense industry, the digital circuit test system is conducive to reducing the production, maintenance and testing cycle of electronic equipment, and improving the combat readiness rate of high-tech weapons, which has far-reaching strategic significance. Now warfare is going digital. With the continuous strengthening of the informatization of weapons and equipment, digital circuits have become an important part of electronic equipment, and countries are scrambling to build digital troops to deal with high-tech warfare. With the continuous deepening of my country's national defense modernization reform, the importance of high-tech weapons has increased significantly. How to ensure the stability of these electronic devices is the key to ensuring that high-tech weapons play a huge role.

However, the existing circuit board inspection systems generally have shortcomings such as low familiarity with test methods, poor reliability, and poor visualization.

Utility model content

The purpose of the utility model is to solve the problems of low familiarity, poor reliability and poor visualization in the circuit board testing system in the prior art.

The technical scheme of the utility model is: a circuit board automatic testing system based on LabVIEW, including a host computer, a data acquisition card, a circuit board to be tested, a reference circuit board, an excitation power supply and some elastic probes, and the circuit board to be tested is equipped with There are a number of test points, a number of power reference points and signal reference points are arranged on the reference circuit board, the elastic probes include a power supply elastic probe and a test elastic probe, the output end of the excitation power supply is connected to the power reference point of the reference circuit board, One end of the power elastic probe is fixed on the power reference point, one end of the test elastic probe is fixed on the signal reference point, and the other end of the power elastic probe and the other end of the test elastic probe are respectively connected to the test point of the circuit board to be tested. contact, the signal reference point of the reference circuit board is connected to the input end of the data acquisition card through the wire, and the output end of the data acquisition card is connected to the host computer through the USB interface.

The upper computer is an upper computer equipped with a LabVIEW platform.

The data acquisition card includes a microcontroller chip, a signal interface module and a signal conditioning module, the output of the signal interface module is connected to the signal conditioning module, the output of the signal conditioning module is connected to the microcontroller chip, and the signal interface The input end of the module is the input end of the data acquisition card, the data output end of the microcontroller chip is the output end of the data acquisition card, and the signal conditioning module amplifies or attenuates the input signal to adapt to the conversion range of the A/D converter.

The data acquisition card includes a power module, the output of the power module is connected to a microcontroller chip, the power module includes a voltage stabilizing circuit, and the voltage stabilizing circuit includes a voltage stabilizer, a decoupling capacitor and a filter capacitor, and the decoupling capacitor One end is connected to the input end of the voltage stabilizer, and the other end is grounded. One end of the filter capacitor is connected to the output end of the voltage stabilizer, and the other end is grounded. The output end of the voltage stabilizer is the output end of the power module. Provide a stable voltage working environment for the data acquisition card.

The signal conditioning module includes a signal conditioning circuit, the signal conditioning circuit includes a voltage follower circuit and an RC filter circuit, the output end of the voltage follower circuit is connected to the input end of the RC filter circuit, and the input end of the voltage follower circuit is a signal conditioning circuit The input end of the RC filter circuit is the output end of the signal conditioning circuit. In order to ensure the quality of the signal and the accuracy of the acquisition, the acquisition signal is preprocessed by the front end and flows into the back end through the voltage follower circuit, and then enters through the RC filter. The prominent feature of the ADC pin of the microcontroller chip and the voltage follower circuit is that its input impedance is relatively high, and the output impedance is small at the same time. The high input impedance can reduce the influence of the circuit on the internal impedance of the input signal source, so that the circuit has better performance. Adaptability and versatility, the low output impedance reduces the impact on the signal accuracy of the back-end processing circuit, thereby improving the accuracy as a whole, and the voltage follower circuit also plays the role of buffering, isolation, and improving the load capacity in the circuit.

The microcontroller chip is an STM32F103 chip, which is a controller based on the ARM Cortex-M3 processor core produced by STMicroelectronics. Cortex-M3 is a 32-bit standard microcontroller based on the ARMv7-M architecture. It has many advantages such as low power consumption, small gate count, short interrupt delay, and low debugging cost. It is specially designed for use in microcontroller systems, automotive electronics, etc. Control systems, industrial control systems and wireless networks and other embedded applications that are sensitive to power consumption and cost are designed to achieve high system performance, which greatly simplifies the complexity of programming and integrates high performance, low power consumption and low cost. .

Compared with the prior art, the utility model has the following effects: the circuit board testing system based on LabVIEW of the utility model realizes the high-speed and reliable testing of the circuit board, and realizes the visualization of the test interface. Overcoming the shortcomings of high cost and long development cycle of previous test benches, the digital circuit test system can reduce the production cycle of electronic equipment and improve the quality and reliability of digital circuits.

Description of drawings

Fig. 1, the overall structure schematic diagram of the utility model;

Fig. 2, the circuit diagram of signal conditioning circuit of the present utility model;

Fig. 3, the circuit diagram of the voltage stabilizing circuit of the present utility model;

Fig. 4, the utility model STM32F103 minimum system principle circuit diagram;

Fig. 5 is a schematic structural diagram of the USB2.0 interface module of the present invention.

In the figure 1. Host computer, 2. Data acquisition card, 3. Circuit board to be tested, 4. Reference circuit board, 5. Exciting power supply, 6. Power supply elastic probe, 7. Testing elastic probe, 8. Power supply module, 9. Microcontroller chip, 10. Signal interface module, 11. Signal conditioning module, 12. Voltage follower circuit, 13. RC filter circuit, N, voltage regulator, C1, decoupling capacitor, C2, filter capacitor.

Detailed ways

Illustrate the specific embodiment of the present utility model in conjunction with accompanying drawing, the circuit board automatic test system based on LabVIEW of the present embodiment, comprises carrying the upper computer 1 of LabVIEW platform, data acquisition card 2, circuit board to be tested 3, reference circuit board 4 , excitation power supply 5 and some elastic probes, the circuit board under test 3 is provided with some test points, the reference circuit board 4 is provided with some power reference points and signal reference points, and the elastic probes include power supply elastic probes 6 and Test the elastic probe 7, the output end of the excitation power supply 5 is connected to the power reference point of the reference circuit board 4, one end of the power supply elastic probe 6 is fixed on the power reference point, and one end of the test elastic probe 7 is fixed on the signal reference point On, the other end of the power elastic probe 6 and the other end of the test elastic probe 7 are in contact with the test point of the circuit board 3 to be tested respectively, and the signal reference point of the reference circuit board 4 is input by the wire and the data acquisition card 2 The terminal establishes a connection, and the output terminal of the data acquisition card 2 establishes a connection with the LabVIEW host computer 1 through the USB interface.

Described data acquisition card 2 comprises microcontroller chip 9, signal interface module 10 and signal conditioning module 11, the output terminal of described signal interface module 10 is connected with signal conditioning module 11, the output terminal of signal conditioning module 11 is connected with microcontroller The device chip 9 is connected, the input end of the signal interface module 10 is the input end of the data acquisition card 2, and the data output end of the microcontroller chip 9 is the output end of the data acquisition card 2.

The signal conditioning module 11 includes a signal conditioning circuit, the signal conditioning circuit includes a voltage follower circuit 12 and an RC filter circuit 13, the output end of the voltage follower circuit 12 is connected to the input end of the RC filter circuit 13, and the voltage follower circuit 12 The input terminal is the input terminal of the signal conditioning circuit, and the output terminal of the RC filter circuit 13 is the output terminal of the signal conditioning circuit.

The microcontroller chip 9 is an STM32F103 chip.

It is used to test whether the components on the PCB board with some or all components installed are wrongly inserted, such as whether the model and parameters of the components are correct, whether the insertion is missing, or whether the insertion is reversed, such as whether the pins of the triode are inserted incorrectly, whether the electrolytic capacitor Whether the polarity of the IC is reversed, whether the direction of the IC is correct, etc., and at the same time, it can also detect whether there is no solder joint, missing solder, etc., which is the main task of the circuit board test.

Described data acquisition card comprises power supply module 8, and the output terminal of power supply module connects microcontroller chip 9, and power supply module 8 comprises voltage stabilizing circuit, and described voltage stabilizing circuit comprises voltage stabilizer N, decoupling capacitor C1 and filter capacitor C2, One end of the decoupling capacitor C1 is connected to the input end of the voltage regulator N, the other end of the decoupling capacitor C1 is connected to the ground, one end of the filter capacitor C2 is connected to the output end of the voltage stabilizer N, and the other end of the filter capacitor C2 is grounded. The output terminal of the voltage regulator N is the output terminal of the power supply module 8 .

In this embodiment, the operating voltage provided by the microcontroller chip is 3.3V, and the power supply module 8 is powered by an AMS1117-3.3V regulated LDO. AMS1117-3.3V is a positive low-dropout voltage regulator, which has the advantages of low dropout voltage, current limiting protection, overheating protection, and wide operating temperature range. The fixed output voltage is 3.3V. When the voltage dropout is greater than 1.2V, the output load current Up to 1A, the voltage is stable, the accuracy is 2%, and the output voltage ranges from 3.234V to 3.366V. In addition, the decoupling capacitor C1 and filter capacitor C2 are added to this part to realize stable power supply for the data acquisition card circuit.

The microcontroller chip 9 of the present embodiment includes a data collection and preprocessing module and a USB2.0 interface module. Only by setting the registers and corresponding program design can the data collection and transmission process be completed, to a large extent The design of the system is optimized, and the devices with high integration are selected in the system development, which is not only convenient for development, but also has high performance and reliability of the developed system. On the other hand, since the USB interface device is powered by the bus, considering the limited output power of the bus, it is helpful to reduce the load of the USB bus by using highly integrated devices as much as possible.

The USB interface power supply can provide a maximum voltage of 5V and a current of 500mA for peripheral devices, which can basically meet the power requirements of small peripheral devices with low power consumption. The USB host can reasonably allocate the power supply, that is, the USB peripheral devices can obtain currents of different sizes through the USB interface to meet their actual needs. In this system, USB mainly supplies power for the data acquisition card, and the USB interface module provides a communication link that conforms to the USB specification for the upper computer and the functional equipment realized by the microcontroller. The USB serial bus has the advantages of fast transmission speed, less system resource occupation, convenient use, easy expansion, support for hot plugging and plug and play, etc.

The USB communication unit provides a communication link conforming to the USB specification for the upper computer and the functional equipment realized by the microcontroller. The USB serial bus has the advantages of fast transmission speed, less system resource occupation, convenient use, easy expansion, support for hot plugging and plug and play, etc.

The USB bus power supply can provide a maximum voltage of 5V and a current of 500mA for peripheral devices, which can basically meet the power requirements of small peripheral devices with low power consumption. The USB host can reasonably allocate the power supply, that is, the USB peripheral devices can obtain currents of different sizes through the USB bus to meet their actual needs. USB mainly supplies power for the data acquisition card 2 in this system.

The USB interface module realizes the data transmission between the host computer and the system memory by sharing a dedicated data buffer through the microcontroller. The USB interface module realizes the detection of the token packet, the processing of data sending/receiving and the processing of the handshake packet. The entire transmission data format is automatically generated by the hardware, including the generation and verification of CRC.

The virtual instrument technology of this embodiment breaks through the hardware-based mode of traditional electronic instruments, and combines the increasingly popular computer technology with traditional instrumentation technology, so that users can operate computers as if they are operating their own defined instruments. It is a brand-new scientific research and engineering design method based on the computer virtual prototype system to conveniently and flexibly complete the collection, analysis, half-section, display and data storage of the measured quantity. Three research design instruments and formats. Virtual instrument technology makes full use of the latest computer technology to realize the functions of traditional instruments. NI's virtual instrument software (LabVIEW) platform provides standard interfaces for all I/O devices, helping us easily integrate multiple measurement devices into a single system, reducing the complexity of tasks. According to different test tasks, users can compile different test software under the prompt of virtual instrument development software to realize complex test tasks.

At the heart of LabVIEW are VIs. VI has a man-machine dialogue user interface - the front panel and a block diagram program equivalent to the function of the source code. The front panel accepts instructions from the block diagram program. In the front panel of a VI, controls simulate the input device of the instrument and provide data to the block diagram program of the VI; indicators simulate the input device of the instrument and display the data obtained or generated by the block diagram program. When you place a control or indicator on the panel, LabVIEW creates a terminal in the block diagram program. Graphical program programming is simple, intuitive and highly efficient. With the continuous development of virtual instrument technology, graphical programming language will become the most promising development direction in the field of test and control.

Claims (6)

1. based on the Automatic Testing System of Circuit Board of LabVIEW, it is characterized in that: comprise host computer (1), data collecting card (2), circuit board under test (3), reference circuit plate (4), excitation power supply (5) and some elastic probes, described circuit board under test (3) is provided with some test points, reference circuit plate (4) is provided with some power source reference point and signal reference point, elastic probe comprises power supply elastic probe (6) and testing elastic probe (7), the output terminal of described excitation power supply (5) connects the power source reference point of reference circuit plate (4), one end of power supply elastic probe (6) is fixed on power source reference point, one end of testing elastic probe (7) is fixed in signal reference point, the other end of power supply elastic probe (6) contacts with the test point of circuit board under test (3) respectively with the other end of testing elastic probe (7), the signal reference point of described reference circuit plate (4) is connected by the input end of wire and data collecting card (2), the output terminal of data collecting card (2) is connected by USB interface and host computer (1).

2. according to claim 1 based on the Automatic Testing System of Circuit Board of LabVIEW, it is characterized in that: described host computer (1) host computer for carrying LabVIEW platform.

3. according to claim 1 based on the Automatic Testing System of Circuit Board of LabVIEW, it is characterized in that: described data collecting card (2) comprises microcontroller chip (9), Signal interface module (10) and Signal-regulated kinase (11), output terminal and Signal-regulated kinase (11) input end of described Signal interface module (10) connect, output terminal and the microcontroller chip (9) of Signal-regulated kinase (11) connect, the input end of Signal interface module (10) is the input end of data collecting card (2), the data output end of microcontroller chip (9) is the output terminal of data collecting card (2).

4. according to claim 3 based on the Automatic Testing System of Circuit Board of LabVIEW, it is characterized in that: described Signal-regulated kinase (11) comprises signal conditioning circuit, described signal conditioning circuit comprises voltage follower circuit (12) and RC filtering circuit (13), the output terminal of voltage follower circuit (12) connects the input end of RC filtering circuit (13), the input end of described voltage follower circuit (12) is the input end of signal conditioning circuit, and the output terminal of RC filtering circuit (13) is the output terminal of signal conditioning circuit.

5. according to claim 3 based on the Automatic Testing System of Circuit Board of LabVIEW, it is characterized in that: described microcontroller chip (9) is STM32F103 chip.

6. according to claim 1 based on the Automatic Testing System of Circuit Board of LabVIEW, it is characterized in that: described data collecting card (2) comprises power module (8), power module (8) comprises mu balanced circuit, described mu balanced circuit comprises voltage stabilizer (N), decoupling capacitor (C1) and filter capacitor (C2), one end of described decoupling capacitor (C1) is connected on the input end of voltage stabilizer (N), other end ground connection, one end of filter capacitor (C2) is connected on the output terminal of voltage stabilizer (N), other end ground connection, the output terminal of described voltage stabilizer (N) is the output terminal of power module (8).