Date: February 27, 2007


NIL ER
-

We should start reading the NIL ER to make note of tests that are run
and compare automatically the SI_MODES.

Under the mps/er directory is a file called C<load>_<two
digits>.er. This is the NIL ER.


Here is an example NIL ER entry.
CAL,ID=C7456,
    SI=ACIS-I,
    SI_MODE=HSE_0002,
    DURATION=(2000.000000,2000.000000,49500.000000),
    OVERLAP=(07456,-00:03:00.000,-00:03:00.000),
    PRIORITY=5
(FROM Sabina)
The overlap parameter tells the OFLS that this ER is to overlap (in
time) the specified OR.  The last two fields modify the start and stop
times.  So this NIL will start up to three minutes before 07456 starts
and end three minutes before obsid 07456 ends.   

The three durations are: nominal, minimum, maximum duration.  By
specifying it this way we allow the OFLS to change the duration of the
NIL to fit the available space.  Thus the overlap parameter sets the
duration of the NIL to perfectly fit within the HRC obs to be
overlapped.  If we set the nominal duration to the true nominal the OFLS
will never use the minimum, so you have to set them equal (just one of
those things).  The minimum is generically set to the shortest NIL we'd
ever do and the max to the largest we would ever make the OR the NIL is
supposed to overlap.

Sabina
Pseudo code:
**change LR to extract this file from the backstop tar**
At the beginning of the load review,

Read in the NIL entries and place in an associative array. 
When there is an obsid update, we pull information from the ocat. If
	this proves to be a HRC observation, then check for a NIL associated
	with this obsid.
IF NIL for this obsid
	set NIL flag in code
	record SI_MODE and duration
	check SI_MODE at time of start science (use the NIL flag)
	check duration at the stop science.(use the NIL flag)
Else
	process as normal

**NOTE, We need to look at examples with mulitple obsid spans and how
to correctly confirm that the times and SI_MODES are correct.