Sample time

Bluesky: The authors emphasize that there is no global exposure time for modern detectors, instead there are: acquire time, acquire period, num exposures, etc.

They are can be set interactively

det.exposure_time.set(3)
det.acquire_period.set(3.5)

or from a plan

yield from bluesky.plan_stubs.mv(
     det.exposure_time, 3,
     det.acquire_period, 3.5)

Sardana: exposure time is specified on the command line as in 'ascan eh_mot65 0 1 10 0.1'. Complicated detectors are dealt with in hooks.