Design And Implementation Of Multi-channel Weak Signal Synchronous Data Acquisition System

Data acquisition is an important means of information access, it has an important effect and widely used in the current information age. The present Data acquisition system is mainly for the large signal acquisition, for a weak signal acquisition system reseach is less.At the same time, the current Data acquisition system’s generality is low, its cost is high and its real-time is low. However, in practical application, the problem to acquisite a weak signal with low amplitude is often need to solve, at the same time, high real-time, high performance and low cost data acquisition system is widely pursued. According to these situation, this paper designed a set of multi-channel synchronous data acquisition system for weak signal, which can acquire weak signal with low amplitude, has good versatility, high real-time, high speed data transmission and low cost.This paper discussed the recent research process and development trend of data acquisition system, introduced the related knowledge of weak signal, explained the practical significance of synchronous acquisition, analysed the framework and the implementation scheme of the present multi-channel synchronous acquisition system. According to the research purpose and research status, determined the system overall design scheme, taking FPGA as the core, using programmable device to build weak signal conditioning circuit based on the variable parameter amplification and filtering,using a variety of communication mode to meet the requirement of generality and scalability.Then designing the system hardware circuit and the system digital logic according to the overall plan and design requirements. The hardware of the multi-channel synchronous data acquisition system is divided into weak signal conditioning circuit, AD7606 sampling circuit, USB interface circuit, W5100 Ethernet interface circuit, Gigabit Ethernet interface circuit, FPGA circuit and power supply circuit to design and realize. According to the system function, the digital logic of the system is divided into signal conditioning parameter setting module, data acquisition and control module, USB communication module, Ethernet communication module, Gigabit Ethernet transmission module, data buffer module to introduce and then using Verilog programming language to realize these modules.Finally, debugging the system hardware and debugging the system function, developed a simple test application program for the system debugging and analysis, realized multi-channel synchronous sampling of weak signal, multi-interface communication and high speed data transmission and data storage, data display and other function, completed the multi-channel weak signal synchronous data acquisition system design and implementation.