高速数据采集系统在ATEM中的实现

针对原TEM(Transient Electromagnetic)发射机在前端电流取样中存在的信号畸变问题,提出在发射线圈中串入纯电阻的解决方案;从数据反演出发分析指出准确记录发射电流下降沿波形,并根据该波形数据计算出发射电流值和电流关断时间;提出选用AVR(Advance Reduced Instruction)单片机AT90S8515,Maxim公司AD(Analog to Digital)芯片MX7821和IDT公司FIFO(First In First Out)芯片IDT7204设计实现一套1.65 Mbit高速数据采集系统,比原采集系统采样速率提高了2倍,采样精度提高了约400%.该系统已成功应用在ATEM(Array Transient Electromagnetic)发射机中,并在多次野外试验中证明,该系统工作稳定,达到了设计目的.

Realization of high speed data collecting system in ATEM

Aim at the problem of signal aberrance in front current sample existed in original TEM(Transient Electromagnetic) transmitter a solution scheme is advanced to put a pure sampling resistance in transmitter winding directly in allusion to current sampling. The accurate record of the shut-off current wave is discussed by the data explain .The transmitted current value is worked out according to the record and the shut-off time is not only necessary but also important. According to the record,a 1.65 Mbit high-speed data collecting system is developed by selecting AVR(Advance Reduced Instruction Set Computer) MCU(Micro Controller Unit) AT90S8515,Maxim company AD(Analog to Digital) chip MX7821 as well as IDT company FIFO(First In First Out) chip IDT7204.The sampling rate of this system is three times of primary sampling rate. The sampling precision of this system is five times of primary sampling precision. This system has been already applied to ATEM (Array Transient Electromagnetic) transmitter successfully so that it is proved to work steadily in several field experimentation and to meet satisfactorily the design request.