Digital waveform generators and analyzers can be configured to acquire and/or generate data once per sample clock period (single data rate, or SDR mode) or twice per sample clock period (double data rate, or DDR mode).

Note DDR is currently available only on the NI 6547/6548 and NI 656x devices.

You can configure the data rate multiplier for your acquisition and generation sessions by configuring the data rate multiplier property/attribute in NI-HSDIO.