Development Of 16-channel Isolated Parallel Ad Module

With the continuous development of China's industrial level,ensuring the stability of industrial equipment is becoming more and more important.The stability of equipment is inseparable from real-time state monitoring.In industry,real-time monitoring of equipment often requires customized measurement modules.In this dissertation,a set of data acquisition board based on CPCI is designed and developed in combination with the practical production needs.A set of data acquisition card based on CPCI is designed and developed.The design problem of parallel isolation measurement of 16 channels in the 3U board space is solved.The accurate measurement of the 16 circuit electrical signals can be realized,and the multiple parameters of a single device can be monitored at the same time or multiple settings can be completed.The simultaneous monitoring of the preparation is of great practical value.In this dissertation,the overall technical index of the module is introduced,and the corresponding requirement analysis is made on the technical indicators proposed in the actual production.On this basis,the overall design scheme of the card is completed,including the overall hardware scheme,the software overall scheme and the overall firmware scheme.In this dissertation,the design of hardware circuit is introduced.The design of hardware circuit mainly includes the choice of analog channel,the design of power supply module and the design of digital circuit module.At the same time,in the overall design,the detailed analysis and design of each module are carried out in detail,and a more complete chip selection is realized.The firmware design part mainly completes the design of FPGA internal logic module,including the design of custom module and the design of Sopcbuilder.The software design mainly includes soft core program design,calibration program design and driving function design.The soft core is designed inside the FPGA,and the IP core is mounted on the Avalon bus.The CPCI bus transfer protocol and other modules are implemented,making full use of the resources in the board.The design of the calibration program based on Lab Windows/CVI is completed,including the remote control of the calibration source by using the SCPI instruction and the linear fitting of the measured data.In addition,the driver function design based on the winning Unicorn operating system is completed.In this dissertation,a board calibration algorithm based on linear regression is designed to solve the problem of measuring data accuracy.By analyzing the measured data corresponding to the specific output voltage of the board,the actual zero point value and the voltage gain coefficient of each channel can be obtained to calibrate the board.In view of the data communication problem of the host computer based on the medium standard kylin operating system,this dissertation studies and analyzes the design process of the driver of the kylin operating system,and designs the corresponding driving function to ensure the need of the data acquisition of the upper computer.After the actual debugging and the calibration of the upper computer,the AD acquisition card system designed and developed in this dissertation can complete the synchronous measurement of the 16 channel data in accordance with the predetermined precision on the premise of parallel isolation.The calibration program can complete the calibration task according to the requirements.The host computer can read the measured values according to the position of the preset memory.The measurement accuracy of the effective value,the DC value and the frequency value of the card measurement can reach the target,and all the functions required by the subject are realized.