configure area det by Msg

msg_conf_area_det.py

import bluesky.plan_stubs as bps
from xpdacq.beamtime import _check_mini_expo

def configure_area_det_expo(expo):
    area_det = xpd_configuration['area_det']
    # compute number of frames
    acq_time = area_det.cam.acquire_time.get()
    _check_mini_expo(exposure, acq_time)
    num_frame = np.ceil(exposure / acq_time)
    computed_exposure = num_frame * acq_time
    yield from bps.mv(area_det.images_per_set, num_frame)
    # print exposure time
    print("INFO: requested exposure time = {} - > computed exposure time"
          "= {}".format(exposure, computed_exposure))