The sample clock is the primary timebase for the digital waveform generator and analyzer. This clock controls the rate at which samples are acquired or generated. Each period of the sample clock is capable of initiating the acquisition or generation of one sample per channel.

Using NI-HSDIO, you can program the sample clock to come from either the onborad clock source signal or an external frequency generator. Because of the pipelined architecture of the digital waveform generator and analyzer, the clock source for the Sample clock must be continuous, free-running, and of a constant frequency for the duration of each generation and acquisition operation.