Read one time-aligned receive block, with the timebase it was taken on.
sample_period_ns on the result must describe the block returned, not the rate last
requested: InstroSDR derives every IQ timestamp from it.
- Parameters:
n_samples (int) – Samples to read per channel.
channels (Sequence[str]) – Receive channels to read, e.g. ("0",).
- Returns:
IQCapture – One row per channel in channels.