Troubleshooting guide

of valid positions. Note that position 0 for each wheel is the home position. As with the MOS script,
the script will print out a detailed information window, the last bit of which shows the desired move.
Answering y at this point will issue the wheel motion command.
For both scripts the wheel motion status will be queried approximately every 5 seconds, and the result will be
printed to the screen. It is unnecessary to hit the Update All Items button on the UFSTATUS GUI during
execution of either of these scripts. It is, however, a good idea to update the GUI after the script has
successfully completed.
Note:
It is not possible to move more than 1 wheel at a time.
The only useful dark position is on the grism wheel; there is a dark position on the Decker wheel,
but its use is not recommended.
Once the script has started moving a wheel, do not attempt to abort it. Just wait for it to finish
moving, and run the script once again.
C. Configuring an Exposure
Several parameters need to be set before taking an exposure. The script config.exposure.pl will print out a
list of exposure parameters, and query if you wish to change any of them. If you do, you can step through each
of the modifiable parameters; enter the new value or hit return to keep the old value. Here is a complete list of
parameters that are printed out:
OBS_TYPE Type of observation being taken; commonly used descriptors include object, standard,
flat, dark.
OBJECT Name of object being observed. NOT provided by TCS.
FILEBASE Image filename's prefix; the naming convention is filebase.####.fits where the
numbers (####) are automatically incremented by the data taking script from 0001 to
9999.
ORIG_DIR Absolute pathname of the directory to which you wish to write data. Make sure you
include the trailing / on the pathname.
DATE_OBS UT date at the end of the night (YYYY-MM-DD).
EXP_TIME Exposure time for integration in seconds. Must be an integer >= 2 and >= 2 NREADS.
NREADS Integer number of non-destructive reads per endpoint per image.
For imaging use NREADS = 1, which corresponds to Correlated Double Sampling
(CDS).
For spectroscopy you can use multiple read sampling:
The minimum value is NREADS = 3.
The maximum recommended value is NREADS = 8.
The minimum allowable EXP_TIME is 2×NREADS.
Note that this script does not always rigorously enforce this condition, so please
double check that EXP_TIME and NREADS are mutually consistent.
For NREADS > = 3 the output image will have signals NREADS times higher than for a
CDS frame; i.e., the output image is a coadd, not a coaverage frame.
A schematic of the readout scheme appears in Figure 3, in the appendices.
BIAS The value of the last requested bias is recorded here. 1.0 corresponds to the imaging bias
at 1.0 V; 0.75 V corresponds to the spectroscopic bias where the dark current is
substantially lower even though the well depth is a bit lower than at 1.0 V. To determine
FLAMINGOS@4-m, Ver. 2.34, 2006 Apr 04 Page 18 of 44