Data Acquisition Control.

ABORT ABORT_POSTCMD ABORT_PRECMD AUTOUPDATE BEAMLINE_PAR BEGIN BEGIN_POSTCMD BEGIN_PRECMD CHANGE CHANGE_FINISH CHANGE_MONITOR CHANGE_PERIODS CHANGE_START CHANGE_SYNC CHANGE_TABLES CHANGE_TCB CHANGE_VARS CHANGE_VETOS DAE_WRITE END END_POSTCMD END_PRECMD GETFRAMES GETMEVENTS GETPERIOD GETRUNNUMBER GETRUNSTATE GETTOTALCOUNTS GETUAMPS LOADSCRIPT PAUSE PAUSE_POSTCMD PAUSE_PRECMD RECOVER RESUME RESUME_POSTCMD RESUME_PRECMD SAMPLE_PAR SET_FERMI_VETO SETSCRIPTDIR SETSCRIPTNAME SNAPSHOT_CRPT STORE SUM_ALL_DAE_MEMORY SUM_ALL_SPECTRA UPDATE UPDATESTORE USER_DETAILS WAITFOR WAITFORDASHRUNSTATE

GETPERIOD ( String  HOST  )  return current period number. Returns: PERIOD number