The Design Of Automatic Calibration Software For Digital Oscilloscope

Digital oscilloscope has been widely used in electronic measurement field as a high-precision electronic measuring instrument. In order to ensure the measurement precision of digital oscilloscope, digital oscilloscope must be calibrated on a regular basis. Manual calibration method is marked with low efficiency, high cost, error-prone and many other shortcomings, which are insufficient to meet the requirement of the calibration of digital oscilloscope. Under this background, we make an in-depth study of digital oscilloscope auto-calibration software based on Lab Windows / CVI integrated development environment and by using virtual instrument technology, the main contents are as follows:(1) By analysis the requirement of digital oscilloscope automatic calibration, we determine the overall software design and make the software hierarchical division and module division through thoughts of hierarchical and modular design, which will help us to complete the design of software overall framework.(2) Application layer design. The main contents include the design of user interface module, the design of software configuration module, the design of instruction inspection module, the design of database module and the design of reporting module. The responsibility of user interface module is to provide the man-machine interactive interface for users; Software configuration module is to improve the versatility of software, by using a custom command-line statement to resolve differences between different instruments? commands; Instruction inspection module is to provide security for software to work properly; Database module is to provide encapsulation for creation of data tables, data storage, data query and other functions, simplifying the operation of the data table; reporting module is responsible for automatic generation and printingof the calibration report.(3) Calibration layer design. The main contents include instrument control module design, system initialization module design, automatic test module design and automatic calibration module design. Where in instrument control module is to realize the control of the instrument by utilizing SCPI commands and using VISA library shielded the differences of instrumentation bus; Instrument system initialization module is responsible for obtaining information and checking the software configuration; automatic test moduleis to realizetheinstrument program control and completion of parameter testby improving keyword parsing efficiency with the help of Hash table data storage structure; automatic calibration module is to provide specific functions for automatic calibration of Digital oscilloscope calibration program.This system can quickly and automatic calibrate the digital oscilloscope through GPIB, USB, LAN or other bus, with the function of error test, error correction, data storage and query, automatic generation of reports and so on. The design greatly improves the efficiency of digital oscilloscope calibration, avoids errors caused by manual operation and is able to keep the system running stably which has a large application and popularization value in the field of automatic calibration of oscilloscope.