SCPI Implementation In The Oscilloscope And Its Application On The Upper Machine

As an important standard in the field of programmable instrument technology, SCPI(Standard Command for Program Instrument) has greatly improved the compatibility between instruments and promoted the rapid development of automatic test system since it has been proposed.This research has realized the function of remote control to an oscilloscope through Windows system by using SCPI standard.SCPI solves the problem of news of programmable standardization in instrument industry.It can greatly save the time of developing program-controlled application of instrument.Once the oscilloscope has the function of SCPI program,it can provide solid hardware foundation for forming the entire automatic test system.This research is dedicated to provide user with reliable programmable function by choosing existing oscilloscope product as research and development platform.This research add a SCPI command parsing module in the existing measuring system for the oscilloscope and develop an upper machine by using Qt Creator software environment in Windows system.The remote control communication between upper machine and oscilloscope is accomplished by a chip named Cy7c68013 a of Cypress company.The main contents have been completed of this research are as following several aspects:1、The design of SCPI command and parsing module.This research builds a specific set of SCPI command according to SCPI specification and measurement function in the oscilloscope. When design the parser in DSP(Digital Signal Process), this research uses a static sequence list to store the SCPI command.Also this research uses an algorithm in combined with linear index and sequential search according to the tree-like hierarchical structure of SCPI command.Above all improve the efficiency of the program execution.This research completes the command response at last.2、the design and implementation of USB(Universal Serial Bus)communication function.This research uses the Slave FIFO(First In First Out)mode of the Cy7c68013 a chip’s transmission.The FPGA(Field-Programmable Gate Array)in the oscilloscope provides asynchronous read/write timing for the affiliate model as an external controller.The initialization and user-defined functions of USB chip are completed according to the firmware framework. This research always has writed the driver interface functions by using Cyapi.lib from the official development kit.After the installation of device drivers, this research realize the two-way communication among upper machine,USB and oscilloscope.3、The design and implementation of upper machine application software.As the part which directs interaction with users, this research plan for it and implement the window procedure for the upper machine by taking advantage of the design of Qt, which has good experience of human-computer interaction.To making the upper machine more smoothly, this research open a thread alone to receive the result data from the query command. When the result data have been stored, depending on the type of data this research should process them after having verified them.In addition, this research have made the installation package based on Windows system for releasing the application.After all the function modules above have been completed, this research based on SCPI finally achieves the target that upper machine remote control oscilloscope, it can lay the foundation of joining automatic test system for the oscilloscope.