研华4711a数据采集卡输出和输入界面，能够采集电压电流信号，能够输出电压和可调的频率的脉冲信号-Advantech Data Acquisition Card 4711a output and input interface, to collect voltage and current signals to the output voltage and adjustable frequency pulse signal

用FPGA产生锁相环控制，随时跟踪输出电压，电流的幅值和频率，采样到实时信息-FPGA PLL