An Efficiency Multiplexing Scheme and Improved Sampling Method for Multichannel Data Acquisition System

Abstract

The paper proposes an efficient multiplexing scheme that is easy to realize synchronous sampling in a multichannel acquisition system with the large number of analogue inputs and different sampling rates. And then, a simple improved sampling control method is also employed to improve the performance. All the technology of implementing the method is by using a low-cost field programmable gate array (FPGA). A sampling lookup table is built by the rule-based synchronous sampling frame structure for the input analogue multiplexers and stored into the internal block RAM resource in the FPGA to reduce the internal wiring resources and optimize the utilization. The improved sampling method obtains several samples in a sampling period and gets the average value as the final output for the sampling channel. In addition, the standard sine wave FFT test method is implemented to test the dynamic parameters of the acquisition channels. The experiment results show that the dynamic performance of the acquisition system is significantly improved. The proposed multiplexing scheme and sampling method can easily be reconfigured for other applications.