Research On General High-precision Data Acquisition Equipment Based On ARM

Data acquisition equipments are widely used in the modern field of industrial measurement and control, data acquisition requirements are increasingly high in various application areas. Data acquisition equipments are developing toward the direction of high-precision, portability, network and intelligent. The common 8-bit or 16-bit microcontrollers are difficult to achieve the above requirements because the microcontrollers are slow and have few resources; Data acquisition cards based on PCI bus architecture have shortcomings such as installation trouble and expensive and can not be controlled remotely. Therefore, the research of general high-precision data acquisition equipment based on 32-bit ARM has great significance.According to the requirements of universal, high-precision and network in data acquisition equipment, it proposed the overall scheme of the general high-precision data acquisition equipment based on the study of embedded system and network transmission technology.The design and development of hardware platform are key elements of this study. The hardware circuit is divided to two parts of main control module and function module based on modular thinking. The ARM master module is designed by embedded system technology, it achieves the function of main control. Function module is fromed by the analog acquisition circuit based on high-precision AD converter and FPGA, the digital acquisition circuit based on optical isolation technology and the network interface circuit based on network interface chip CS8900A, it achieves the acquisition of 8-channel analog signals and 8-channel digital signal and the communication with the control terminal through the network.In terms of software, the Linux device driver of data acquisition circuit is developed based on the embedded Linux operating system platform, it achives the management of the data acquisition hardware by the embedded Linux operating system. The client-server network communication procedure is developed by using the TCP/IP protocol and achives the communication between data acquisition equipment and the host computer, it provides the software support of network requirement on data acquisition equipment.Laboratory test results show that the general high-precision data acquisition equipment based on ARM meet the design requirements in the parts of functions and performance. The data acquisition equipment has wide application prospect in the field of industrial measurement and control.