MDM Trouble Report for 2001 May 25

Telescope: 2.4m
Observer(s): Vestergaard (OSU)
Instrument: CCDS

Problem(s) Encountered:
Electronics: First sign of problems with the electronics occured
when taking flat fields late afternoon: I got the first corrupted
data - but it seemed to recover, so I didn't take action. The
problem severely worsened as I started taking my first science
data. It started with `Warning: Instrument Electronics not 
responding' when I send system commands in Prospero. Then I
got time-out messages. IC PC showed `port 8 not available'.
I then did `ic uartinit', `wc config' (all components and electronics
were up and running, though), and then did `startup'. It seemed
to clear it for 1-2 exposures, then it returned with `Warning:
No response' (and corrupted data). I repeated the above. The scenario repeated itself
but this time `startup' refused to recover. I then quit the
program on the IC pc and cycled the power, checked the wc with
`>AL PING', and `config', all was well. `>IE ping' on the IC PC
also returned an ok. I did `startup' in prospero again, quit
and started caliban again. This appeared to synch the PCs ok
and  the instrument and associated electronics worked fine for
the rest of the night.

The TCS computer started giving problems at midnight by first showing the
wrong epoch for the current possition (showed epoch 2000.0).
[This I noticed just before the following happened].
When sending the next coordinates to the tcs, it would start
initiating a move to these coordinates, EVEN WHEN TRACKING AND
GUIDING on a target already! I resend the coordinates it should
use (when it stopped), but it kept bouncing between the two sets of coordinates.
I clicked `stop' in xtcs and went to dome only to find the telescope
pointed far south and into the dome (it was supposed to be close
to Zenith). I couldn't move the telescope manually as it hit 
the hard limit and cut the power to the drives. I followed the 
procedure in the manual (ie cycled power to tcs computer). However
close to Zenith, the tcs thought it was hitting the limit so
I had to cycle the power to the tcs again to get it back to Zenith.
I reset the coordinates with the tiltmeters and a saostar,
but had problems for the rest of the night finding any familiar target,
even saostars. I tried to restore the coordinates several times
but I couldn't recognize any of the fields I pointed to. However
it seemed to find Zenith ok (judging by the tilt meters).

Immediately after the telescope was rescued out of the hard limit
I noticed that the focus was very much off and I had to change
the focus about -250 units to see any stars. THe unfocused
stellar images seemed to indicate that the central `donot-hole'
was not centered on the image of the primary mirror, thereby
indicating that the telescope may not be collimated any more.
Perhaps this adds to complicate any pointing? 

I know it is weekend and holiday, but I would really appreciate
to get some help - at least via the phone. I am not sure what
to do about the collimation, if at all possible. Also, if the
tcs doesn't come up and point well tomorrow, it isn't clear to
me what to do, since I have already tried resetting the encoders
with the tiltmeters and the `reset RA/Dec encoders' button. The 
manual doesn't seem to say as far as I can tell (or am I too
cross-eyed and tired?). If the telescope indeed is out of it's
collimation, can I still observe ok (but will just get the
light distributed differently) or is that no use?

Thanks!
PS: Should I submit a trouble report as soon as problems have
happened or is a report in the morning plenty early?

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Submitted on 2001 May 26 [5:24:53]