Subject: 2.5m obslog 990817 (MJD 51409)
Date: Wed, 18 Aug 1999 04:52:21 -0600 (MDT)
From: hayes@apo.nmsu.edu
			Monday August 16, 1999
                   Apache Point Observatory SDSS 2.5m
                           Observing Log
Observing Team:
		Jeffrey Hayes (APO)
		Ellyne Kinney (APO)
		Stephanie Snedden (APO)
		Connie Rocosi(UC)
                Scott Burles (UC)
                Matt Newcomb (APO/CMU)
                Chas Briegel (FNAL)
                Russell Owen (UW)
Opened at 6:30 pm MDT.  We had partly cloudy skies and low (40%) humidity.
No forest fire tonight, and the dust count was tolerable (~2000).
The 2 spectrographs, cartridge 1 and the corrector, along with the
petals gives a counterweight voltage of 475.  With French's help, we also
found that we needed an extra 36 lb counterweight for the rotator imbalance
which was causing a front/back balance problem.
We used the 1.7' pointing model of 16 August 1999 for tonight's labours.
We tested the MCP commands to open/close thr spectrograph doors and the
latchs.  While the keystrokes worked, the MCP will not update the Menu
correctly about the status of the latch -- it reports unlatched
whether it is or not.
Connie was still having problems with the primary galil.
Steph and Jeffrey crossed the fiducials initially.
The guider Mac needed to be rebooted, and we found that the latest version
of the spectrograph instrument block has a problem -- the Guider camera
is not seem by the TCC in this version.  However, version 14 of the
instrument block (from May 1999) works fine.
We were to test guiding.  We used cartridge 1 and plate 172, with a centre
of 325.7, 0.  We found an FK5 star at 326.808213, 2.686117.  After some
experimenting we found the focus to be at 1900.
Testing the "sop" guider: we started at 12:50 am MDT.
We also learned about "sop", and how to command the TCC through "sop", but there
appears to be a lower level problem with the TCC talking to the MCP.  We have
repeatedly verified that the MCP will freeze up if more than a single
offset command is issued without a sleep command of a length of at minimum
of 5 seconds between offset commands.  This happened 4 times.  We tried
a soft reboot of the MCP, but this did not work, so hard reboots were
required for each.  (We are worried that this may wear-out the button.)
We did compare the co-ords of all the axes before and
after each of the reboots and found that the positions did not change overly
much, except on the first reboot when the ALT position changed by 20'.  We
did manage to restart the guiding attempts without needing to reset the
fiducials on the MCP.  However, for the 5th freeze-up we did need to reset
all the fiducials.  In this case, we could not find the valid AZ
fiducial at all, but we could find the fiducials on either side (i.e. 32 and 34)
and so we just worked with the position as it was.  The errors the TCC
gave before the freeze-ups are:
0 0 F Modu="prt_ReadReplySet"; Text="too many replies on port LTA19:"
0 0 I Modu="prt_ReadReplySet"; Text="the following replies were read:"
0 0 I Modu="prt_ReadReplySet"; Text="ERR: bump active"
0 0 F Modu="axe_o_Move"; Text="command failed for TEL1, TEL2 , IR"
0 0 I AxisStop="TTT"
0 0 W Text="move failed; axes halted"
We finally started guiding in earnest at 2 am MDT, and successfully continued to
guide without mishap until 3 am.  We obtained some 97 iterations of guiding
on this field, thereby demonstrating that guiding using the "sop" guider
can be done for a typical integration time for a plate.
At 3 am we started to play with the guider (i.e. try to break it) by
applying offsets to the field, and then restart the guider to see if it
could pick up the stars, recentre then and continue guiding.  We tried moves
in x=-5'', y=0''; x=0'', y=5''; x=5'', y=-5''; x=0'', y=0'', rotation=130''
(in steps); and finally x=5'', y=5'', rotation=40''.  In all cases, the
guider successfully found, recentred and started guiding again!
All in all, apart from the MCP troubles, a very good night.
As the current field was too far to the west, we defered tests of the TCC guider
until tomorrow (along with more ideas for further tests for guiding).
We closed up at 4:45 am MDT.
Ellyne and Jeffrey for all