Integrated Capacitor Automatic Test System Based on VEE

　　

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　　The ratio of the center frequency to the passband is the quality factor, denoted as Q, that is
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　　the theoretical idea of ​​this design is: the input sine wave amplitude is fixed and the frequency is changed. When the input frequency is ω0, the voltage across the resistor R is the maximum. The test can be made by comparing the frequency at the maximum output waveform voltage with the theoretical ω0.

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　　Three instruments are used in this design, namely HP's HP54602B oscilloscope, HP's HP33120A function generator/arbitrary waveform signal generator, and Fluke's 8840A multimeter. These instruments all have a general purpose interface bus (GP IB). Each instrument has a unique GPIB address in the automatic test system. The computer used is equipped with a GPIB interface card. It is connected to various instruments through the bus to form an automatic test system. The PC programs and controls the test instrument through the interface; through multiple GPIB interface cards, close-range high-speed parallel data communication between microcomputers is realized.
2.1IEEE-488 (GP-IB) interface
　　Most modern intelligent instruments have two working modes: local (local) and remote (remote). In the local working mode, the user issues various commands to the instrument through the keyboard to instruct the instrument to complete various actions. In the remote working mode, the controller (usually a computer) issues various commands to the instrument through the GP-IB interface bus. The interface is a key component for intelligent instruments to communicate with the outside world. The GPIB interface bus has 16 signal lines: 8 DIO data lines, used to transmit various multi-line messages; 3 hook lines, used to ensure reliable transmission of information; 5 interface management lines, used to manage the working mode of the interface.
2.2 Agilent VEE software
　　Agilent's VEE software (Visual Engineering Environment) is a graphical programming language for instrument control, supporting multiple working platforms such as MS Windows, HP UNIX workstations and Sun SPARC workstations, and is also one of the main software development environments for VXI bus test systems. It is a modular flowchart programming language, which uses data lines and control lines to connect various modules together to form the entire program.

　　The following is the VEE test program (see Figure 3). All results are generated by VEE simulation. The program generates a frequency sweep process by VEE (see Figure 4), and then the multimeter randomly generates a voltage value at each frequency (see Figure 6), and outputs the maximum value after comparison. This series of processes are set by the main program, and the output operator interface is shown in Figure 5.