Subject: DSC news #1


Submitted: Fri, 26 Jan 96 17:12:34 -0600

Message number: 17 (previous: 16, next: 18 up: Index)


There is a new version of DOP in place at APO.
This was required because there is a new version of the data
acquisition software. The new dop version is v3_1, but we will 
be making better use of the SDSS software environment
and the most current version of DOP will be automatically
available.  In other words you now just type:
	% setup dop
and the most current version is setup correctly, including 
the right DA software. Then, to run the system you type:
	% dscRun
and you are off. This sequence should remain true no
matter how many version of the software we make. You will
have to read the primer after that point. The most current 
documentation may be found by doing a:
	% xmosiac $DOP_DIR/doc/www/dop.home.html
after, of course, setting up dop.

The new DOP is different structurally from the old one,
but most of the changes will be invisible to the
casual user. The two most noticeable changes 
are 1) headers (including time, ra, and dec) are now updated
 between frames of a drift and are handled by the DA, and 
2) the message windows from the cam and tc shells have a 
notion of history.  (For experts, the other changes are:  
the ccd programs are handled much differently;  the camera has 
a notion of status; the camera shell and telescope shell no longer
can talk to each other, only the main user shell can talk
to both; and status is no longer handled by distributed objects,
instead they are handled by remote procedure calls; much general
cleaning up of code and removing of obsolete commands.)

We continue to recommend the commands:
	goStare <expTime> <Objname>
	goDark <expTime> 
	goDrift <nframes> <Objname>
	goDarkDrift <nframes> 
There is also a pair of commands to help with short driftscans:
	offsetDrift <nframes>
that move you over n frames and starts a drift scan at the current
driftscan rate (usually 0.7 sidereal, see [CAMStatusGet drift_rate]).
endOffsetDrift  puts you back at the home position and stops
the drift. Currently, this will make you drift from south to north.

For experts, the main commands remain:
	cc beginUnixReadout
	cc beginDrift
	cc endReadout
though the first two now optionally take an argument to keep the
shutter closed (i.e., beginUnixReadout 0 is a dark frame).

In case something goes very wrong and you need to return
to a previous  of DOP, there is a command in the new DA
software (versions v3_0 and higher) that will allow you to
switch back. The sequence is this. 
	% less /p/ups_database/declared/dop
		and see what version of astroda you need for
		the version of dop you want 
		(for example, x2_0_0 for the v2_3 dop)
	% dscSwVer -s <version>
		(for example: dscSwVer -s x2_0_0 )
	% setup dop <version>
		(for example: setup dop v2_3)
	% dscRun -s <version>
		for astroda versions greater than v3_0
		OR %dscRun dsc    for astroda version x2_0_0
	fnstar-OAC> poolInit
		is required, and which will delete any data
		on the VME side.
At that point, you may follow the primer of the corresponding
version of DOP.  We don't expect you to need this command, but 
you should be aware of it.

James Annis

APO APO APO APO APO  Apache Point Observatory 3.5m  APO APO APO
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