在Timed Loop的Loop Configuration对话框中,对Timing Source选择use terminal,从All Functions->NI Measurement->DAQmx_->DAQmx Real-Time->DAQmax Timed Loop中选择DAQmx Create Timing Source.vi,设定要作为Timing Source的Counter和Frequency,然后把输出端timing source out连接到Timed Loop的source输入端,