该程序是在VC++6.0环境中，用C++语言编写的，分三个模块：一个是程序框架模块，实现程序的框架结构；二是声卡采样模块，实现声卡对外部模拟信号的采样；三是对采得的信号进行频率值计算。-procedures in the VC 6.0 environment, the use of the C language in three separate modules : is a procedural framework modules, achieving procedural framework

利用Blackman窗函数对工频信号进行加窗FFT后校正计算出基波和谐波的幅值、频率和初始相角。-Blackman window function using frequency signal windowed FFT is calculated after the correction of fundamental and harmonic amplitude, frequency and initial phase angle.

互相关原理解决控制后系统频率测试的程序，给定传递函数以及输入信号求控制系统输出。（感觉和理论结果有差距，可以用来参考计算过程）-Correlation theory resolved frequency control system test procedures given transfer function and input demand signal control system output. (Theoretical results and feel there are gaps,