According to the specific characteristics of the PCB board, the method of on-line test is selected, and one or more processes are combined together to learn from each other and apply synthetically. The following describes the PCB board intelligent detection methods.
  
First of all, used in PCB board to the thought of virtual instrument, establish relevant software, through the software to achieve the various functions of the traditional instrument including oscilloscope, signal generator, and the collected data in various mathematical processing. When testing, digital signals are given by test software.

Then, the test system of PCB plate will have new design ideas, the design idea of USB bus automatic test system based on virtual instrument and computer, give full play to the role, as far as possible by the computer instead of the traditional instruments, so as to reduce the volume of the instrument itself, reduce development costs, thereby improving the the efficiency of the development.

Next, after D/A conversion and analog excitation signal to test applied to the test system, the test circuit through the test bus to the matrix switch, switch matrix and connected at the same time by the microprocessor control is turned off, the measured PCB plate is fixed on the needle bed, the excitation signal by applying to the corresponding position of the printed circuit the board, by the test circuit to measure the response of the analog acquisition, into the core control, through A/D conversion, and corresponding digital machine, by PCB software through feedback and PCB processing, PCB board to determine whether or not qualified.

This on-line test technology breaks through the previous method of using human eye detection circuit board, and the on-line testing technology has high efficiency and low detection rate, thus realizing the automation of the detection field. This system adopts the idea of combining with virtual instrument, reduces the design of hardware, and reduces the cost of the whole system.