说明：  通过数据采集模块计数器对输入光栅尺脉冲信号进行计数，脉冲与光栅尺移动距离一一对应，每个脉冲对应一个栅距，由脉冲数与栅距乘积得到光栅尺直线位移；计数函数采用与数据采集模块对应的usb2k1.dll库函数。
(Through the data acquisition module counter input grating pulse signal count, pulse and grating moving distance correspondence, each pulse corresponds to a pitch by multiplying the number of pulses and pitch grating linear displacement counting function and data used acquisition module corresponding usb2k1.dll library functions.)