Software Design Of AD Of PXI Bus Based On Linux System

In modern industrial testing,the analog-to-digital converter module,AD,is the core of building an automatic test system.The specific functions are real-time signal sampling and data storage,generally with multiple channels.The traditional concept believes that instrument development mainly revolves around hardware,and the pursuit of hardware indicators ignores the development of software.Only hardware stacking can improve performance and cost greatly.The AD module software designed in this paper uses virtual instrument technology,which has the characteristics of good reuse,high integration and strong customization.It is developed on the Linux platform,runs stably,is based on the PXI bus,is compatible with PCI,and has fast transmission speed.Reliable electrical performance,strong competitiveness in similar products,make full use of software advantages,can make a breakthrough in the field of automatic testing,and save hardware costs.This article mainly explores the AD module software in depth,puts forward a software design plan,and selects the best plan after comparison.The whole software includes three parts: function interface,instrument driver and human-computer interaction program.Finally,check whether the software function is normal through the signal test.The main research contents are as follows:1.Under the Linux platform,after studying the PCI bus configuration space and IO bus,the AD module driver is developed through the Linux kernel.Module drivers are mainly divided into initializing device modules,opening device modules,data reading and writing modules,interrupting modules,releasing device modules,and unloading device modules.It realizes the identification of the device by the Linux operating system and guarantees the bottom communication with the hardware.2.In order to better develop the upper-layer application,first define the function register,standardize the instruction,and implement the corresponding interface function function to control the AD module according to the AD mod ule function classification.The entire function interface conforms to the IVI design specification and receives the parameters of the upper-layer application The information is converted to the corresponding command and transmitted to the FPGA side through the driver,and the data returned by the FPGA is accepted.The implemented API is mainly divided into five functional modules: instrument initialization,sampling parameter configuration,trigger signal configuration,sampling data processing,and error correction.3.On the basis of the AD module function interface,the human-computer interaction program is developed through Qt to provide a concise and clear interface,which is convenient for users to configure various parameters of the AD module,especially the use of table controls to facilitate multi-channel settings and provide Multi-channel waveform display,the corresponding multi-thread technology is used in the design to prevent the program from performing other operations during the sampling process and causing the program to crash.4.Finally,the function verification of the AD module is carried out.First,the system driver joint debugging is carried out to ensure that the underlying data communication is correct and the driver runs normally.T he trigger mode is configured through the human-computer interaction program to control the AD multi-channel sampling.The channel analog input signal is sampled and displayed,with the capability of waveform analysis,and the software design meets the requirements.