Design Of Multi-channel Acquisition Equipment Based On Gigabit Ethernet Transmission

In aerospace and aeronautical engineering tests,it is necessary to collect and transmit equipment to collect and store various functional indicators of the aircraft,and to read back the data after the test is over,so as to facilitate the analysis of the working parameters during the test of the aircraft and provide data for performance optimization or technical improvement in accordance with.This paper investigates the domestic and foreign research status of acquisition and transmission equipment,combined with actual needs,adopts modular design ideas,and designs three aspects of multi-channel acquisition interface,multi-type data mixed package storage,and data transmission.1.In terms of acquisition,the analog data adopts a multi-channel asynchronous sampling structure,which simplifies the sampling circuit;for the analog data with different sampling rates,matrix-type framing technology is used to realize uniform sampling in the time domain,improve sampling accuracy,and pass The FPGA controls the ROM lookup table to switch the acquisition channel and improve the A/D conversion speed.2.In terms of storage,communicate with the memory through the LVDS interface,add an equalizer at the receiving end to compensate for signal attenuation;use analog-digital hybrid packaging technology for different types of data collected to improve storage efficiency.3.In terms of transmission,the "FPGA+PHY" method is used to design the Ethernet interface circuit to simplify the internal logic of the FPGA;the Gigabit Ethernet communication is realized through the UDP/IP protocol.On the basis of the UDP protocol,the dual RAM alternate buffer is used.In order to improve the transmission rate;in view of the packet loss problem in the UDP protocol,a CRC checksum request/retransmission protocol is added to the Gigabit Ethernet link to improve transmission reliability.By building a test platform,the function of the equipment is verified.The analog sampling accuracy,transmission data bit error rate,and Ethernet transmission rate were tested respectively.The results show that the sampling accuracy is 0.488‰,which is better than 1‰,the bit error rate is 0,the maximum transmission rate is 68.4MB/S,and the average transmission rate is 66.1MB/S.Finally,the request/retransmission protocol of Gigabit Ethernet is tested to prove that the transmission protocol is reliable.