Most header info is latched right after wipe has finished and integration started. But note that this is before the shutters are opened and most lamps turned on. We play a game so that we get the commanded lamp states (from DCB and later pfiLamps), but not measured currents. We do not even do that for the shutters: the ENU W_ENSHUT value is always "close"

Think out what we actually want and can safely provide. We want to do this right for bias, 1-second calibration exposures, and "long" exposures.