 | IDL> obj = obj_new(hsi_obs_summary)
 | IDL> data = obj -> getdata(obs_time_interval = 1-SEP-2000+ $ [ 01:00, 02:00])
 | IDL> data= obj -> getdata(filename =hsi_20000901_0000_001.fits)
 | data is a structure with countrate and time
 | To plot:
 | IDL> obj -> plot
| | | | | |