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CCD Controller News (1Mar93)
(from CTIO, NOAO Newsletter No. 33, 1 March 1993)

Two major milestones have been passed.  First, ARCON 3.1 has been
completed, and with the new quad dc-coupled pre-amp the video chain
demonstrates state-of-the-art noise performance (3 e- rms with the
Thomson 1024 CCD).  Second, the conversion to operation with S-bus
rather than VME-bus has been finished. On December 3 at the 0.9-m
telescope, ARCON 3.1 was operated with a Sparcstation 10 and delivered
high-quality images. On this engineering run the user interface (which
looks like the KPNO "ICE" to the observer) was also tested, as was the
hook-up to the Telescope Control System. Further engineering nights are
scheduled in late January and in February. Over this period we also
intend to carry out a mini-project to remove the participation of the
old VEB controller in the operation of the filter wheels; during March
we hope to finally retire the 0.9-m VEB.

Meanwhile, work is proceeding to implement ARCON 3.2 (Tek 1024) and
ARCON 3.3 (Tek 2048). Due to pressure from other projects and the
usual slow-down over the summer vacation season, this work has gone
somewhat slower than anticipated, however completion is expected in
early 1993. We also anticipate making rapid progress on the software
front, now that the S-bus conversion is complete.

During 1992, ARCON 2.1 (Thomson 1024 CCD) was regularly used at the
Schmidt telescope for service observing, in addition to its development
role in La Serena. With work now being transferred to the (production)
ARCON 3 series, ARCON 2.1 and its VME-based Sun computer will be
stationed permanently in the Schmidt, and once again visitors will be
able to carry out their own CCD programs. We should warn however, that
the observing software was frozen many months ago and is much more
primitive than that now used with ARCON 3. There is only a simple
command-line interface and several traps for the unwary. This is not to
imply that good data cannot be obtained, quite the opposite. The
Thomson CCD is sensitive from 3000 A to 10000 A; readout takes about 12
seconds and de-scrambling of the (quad) data just a few seconds longer;
the controller produces pictures free of any electronic interference,
in addition to being impressively reliable.

Alistair Walker

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