The Local Control Software Design Of Oscilloscope Calibrator Based On Linux System

The oscilloscope calibrator is an instrument that can generate a variety of high-precision test signals and is mainly used to calibrate various parameters of the oscilloscope.With the continuous development of embedded technology,the application of embedded technology to the design of oscilloscope calibrator enrich the function of the instrument.Because the instrument software acts as an information interaction tool between the user and the instrument,the software's stability,operation complexity and interface aesthetics directly affect the user's operation of the instrument.In order to realize the control function of the local control software to the oscilloscope calibrator and improve the user's operation experience of the instrument,the subject researches the local control software of the oscilloscope calibrator based on the Linux system from the instrument control program and the instrument communication driver program.The instrument control program adopts the C/S design mode and is developed by the Qt design tool that is divided into client program and server program.The client program is mainly used as the instrument operation interface program.It has good cross-platform nature,and can be recompiled according to different system platforms to obtain the same operation interface of instrument.The server program is mainly used to process instrument parameters and control hardware function modules.The client program and the server program transmit data through the network loopback address.The data format is defined by the SCPI standard syntax.The instrument communication driver program mainly completes the data exchange between the instrument control program and the hardware modules so as to realize the control of the instrument control program to the hardware modules.The essential research content of the thesis is presented based on the above analysis.1.Designing network communication program.The program includes the thread scheduling and thread reuse design to achieve the management of the thread class object,thus avoiding multiple clients access the instrument at the same time an error.2.Designing instrument parameter management program.The parameter processing process of different hardware function module is abstractly designed as a different parameter processing module,and a corresponding parameter processing module is dynamically instantiated according to the waveform type selected by the user,so as to ensure correct processing of different waveform parameters.3.Realizing the calibration of the signal amplitude of the amplitude-stabilized sine wave module.According to the hardware design of the amplitude-stabilized sine wave module,the output signal of the hardware module is measured by controlling the internal hardware circuit,and the measured data is fitted by the least squares method so that the calibrated signal parameters meet the requirements of the index.4.Designing instrument communication driver program.According to the design of hardware interface and data transmission protocol between the main controller of the instrument and the FPGA of the peripheral expansion device,the driver program of the FPGA device under the Linux system is realized.