== Example of PV phase script translated from its IST phase structure ==

''' Header's information
{{{
// $Id$
// Missionphase  : PACS PV Phase
//
//
// Version       : 0.1
//
// Purpose       : Schedule the associated CUS procedure
//
// CUS author    : DAC
//
// Input arguments
// type    name         description
//
// Return values
// Type    Name        Description
//
// Description   : Set/resets OBSID, calls associated procedure
//
// Dependencies  : see associated procedure
//
// Preconditions : see associated procedure
//
// Comments      :
// 
// History       : 0.1 22-mar-2006
// History       : 0.1  11-feb-2008  Converted into Eng OBS by VDP
//
}}}
Declaration of script typre as observation (e.g. inc. a pointing request) and X-HSPOT readable variables
{{{
obs PacsEng_Spec_Gra_Diaghk_Setup {

/* No variables to call PacsEng_Spec_Gra_Diaghk_Setup                        */
    int diag_hk_period = 5; // 5 msec diag hk period 
/* string fltPOS = "POS A"; //Filter wheel position 0="POS A", 1="POS B" */
/* End of needed variables for PacsEng_Spec_Gra_Diaghk_Setup                     */
}
}}}
Internal variables declaration, and timing computation
{{{
{

// Four arguments needed for "no_pointing"
// 1. Execute the pointing request
  bool execute = true;
// 2. Initial hold
//    Write OBSID during initial hold
  int tih = duration(WriteOBSID($OBSID));
// 3. Final hold
//    Declare OBS finished during final hold
  int tfh = duration(WriteEndID());
// 4. Duration of "stable" pointing
  int tp = imax(1,duration(PACS_Spec_Gra_Diaghk_Setup(diag_hk_period)));
}}}
Pointing request: this is a `PacsEng` script so a `no_pointing` request is necessary, because the system expects a pointing request of some sort nontheless
{{{
// Issue PointReq
    int[] ts = no_pointing(execute,tih,tfh,tp);
}
}}}
State machine: even though there is no actual pointing, the observation made during the tests require the telescope to be "On SRC"
{{{
{
// Start observation.
// STATE_MACHINE logic. 
// OBSID is handled during initial and final hold times. Otherwise, consider
// only stable pointing
  int[] state = [0];
   while(state[0] >= 0)
     {
      state = next_state();
      if(state[0] == 2)
        {
//        Declare start of OBS
          WriteOBSID($OBSID);
	}

      if(state[0] == 3)
        {
//        Call the required procedure
          PACS_Spec_Gra_Diaghk_Setup(diag_hk_period);
	}
      if(state[0] == 5)
        {
//        Declare end of OBS
          WriteEndID();
	}
    }
// End of observation
}