From: AAO40A::TJF
Date: 15-MAR-1996  14:31:08
Description: Programmed observing and beam switching                 

For users of the AAO OBSERVER CCD/IRIS System.
Programed observing changes
Some of you may be familiar with the facilities provided by the OBSERVER
CCD/IRIS system which support programmed observing.  The is normally done via
the RVICL command and the more common use of this in the past has been to
implement IRIS mosaics using the offset run facilities. These facilities can
in fact be used with normal CCD's, as well has IRIS, and there are commands
supporting use of offset files without doing the actual offsets (for testing
etc) and suppport for polarimetry runs.
The programmed observing facilities have now been extended as described
below to allow a far greater range of operations.
To do telescope offsets, you would normally use the "OFFSET_RUN" icl command
together with a file you have written which describes the offsets and
the images to take.  Alternately, you could use the same run description
file with the "PROG_RUN" command to take images without offsetting the
telescope (the offsets are ignored), the "POLLOFFSET" command to do an
offset run in polarimetry mode and the "POLPROG" command for polarimetry
mode programmed runs (offsets ignored).
All of these commands now support a new facility which, amongst other things,
allows you to do telescope beam switching between images.  If a line in the
run description file used above begins with an "at" (@) symbol, then the
rest of the line is taken as an ICL command to be executed.  Since commands
to beam switch the telescope are now available, your run description files
can now beam switch the telescope.  Since beam switching can be done while
autoguiding (if using the image-dissector auto-guiders, the prime focus
ST4 auto-guider cannot be controlled by the VAX), it may be better for your 
application then offseting. For example, consider the following offset run 
description file.
DARK _DARK      0.01 0.01 TRUE  5  5 1.5 1
SKY  _SKY       0.0  0.01 TRUE 10  2 3.0 1
RUN  OBJECT_A  -0.01 0.01 TRUE  7  1 3   1
RUN  OBJECT_B   0.0  0.0  TRUE  5  5 1.5 1
When specified to the OFFSET_RUN command, this file causes 4 images to be
taken with the telescope offset to a new starting point before each one.
When specified to the PROG_RUN command, the telescope offsets are ignored and
four runs are taken.
The following file is a modification of the above file which beam switches
the telescope.  The lines starting which @ are ICL commands.  The SET_AXES
and SELECT_AXIS commands used in this case are described below.
@SET_AXES 0 0 10 10 -10 -10
DARK _DARK 0.01 0.01 TRUE 5  5 1.5 1
SKY  _SKY  0.0  0.01 TRUE 10 2 3.0 1
RUN  OBJECT_A  -0.01 0.01 TRUE 7 1 3 1
RUN  OBJECT_B 0.0 0.0 TRUE 5 5 1.5 1
SET_AXES rx ry ax ay bx by
	Sets the offsets for each of the telescope axes.  Parameters are
	the x and y offsets in mm on the focal plane for each of
	the reference, a and b axes.
	 Note that although this facility is available, normally, the
	 the axes offsets are setup by the night assistant
	Selects a telescope axis
	The parameter has a value from 0 to 5 or A,B,R where
		0 = R = Select reference axis, disable control panel buttons
		1 = A = Select A axis, disable control panel buttons
		2 = B = Select B axis, disable control panel buttons
		3 = Select reference axis, don't  disable control panel buttons
		4 = Select A axis, don't disable control panel buttons
		5 = Select B axis, don't' disable control panel buttons
So you can see the the above file will set up the axes offsets, and then
select the reference axis before taking the Dark exposure.  It will then
select axis A before the Sky, axis B before the first run and the reference
axis before the second run.
In theory, the above file can be executed with any of
OFFSET_RUN, PROG_RUN, POLLOFFSET and POLPROG, but is only makes sense to
do it with PROG_RUN and POLPROG.
Since the @ symbol can be used to execute any ICL command a lot of other
things are possible, for example, slewing the telescope.  These commands are
executed while the previouis integration is being read out so you should not
loose time waiting for the telescope to move before the next integration.
If you need to execute commands which require the CCD system be idle, such
as WINDOW, SPEED and METHOD commands, first execute a WAITFORIDLE command,
for example-
RUN  THE_OBJECT 0.0 0.0 TRUE 7 1 3 1
RUN  THE_OBJECT 0.0 0.0 TRUE 5 5 1.5 1
This file waits for the CCD system to go idle before changing the window and
Please see me if you want to do other operations or you need help
writing one of these files
Tony Farrell
Refresher on offset file layout.  For lines not starting with a @ or !, the
items are
2. OBJECT_NAME (a string but must not be the same as a control
			task command (just prefix and underscore if unsure)
3. Offset in RA
4. Offset in DEC
5. Cosdec Flag
6. Exposure time
7. Cycle count
8. Period
9. Repeat count (Number of runs at this offset)
Spaces are not significant but use ONLY spaces as separators
For example
! 1.  2.     3.   4.   5. 6. 7. 8. 9.
DARK _DARK 0.01 0.01 TRUE 5  5 1.5 1