MDM Observatory's 8K CCD array project based at Columbia Astrophysics Laboratory: RESCUE PROCEDURES IN CASE OF FAILING EXPOSURES
Arlin Crotts e-mail: (
Telephone: (212) 854-7899

These procedures are to be followed only in the event of a failed test exposure at the start of an 8K setup, or if such problems develop during an 8K run resulting in a persistent failure of exposures.. Be sure you know how to properly display an 8K image before starting these procedures, and check whether image files are actually being written to disk with each exposure. If exposures are being recorded, but there seems to be a problem with the shutter, follow the failing shutter procedures and not those below. Verify that you are viewing the proper image file directory. This also assumes proper communications between the control computer and 8K over the fiber optics link. To test this communications link, look here.

All of the steps in the procedures below are detailed in the 8K Basic Startup and Shutdown Procedures manual page.

IN THE UNLIKELY EVENT THAT EXPOSURES PERSIST IN FAILING, try the following procedures (in increasing order of severity):

1) power the instrument off and on i.e.
turn off SLAVE,
turn off MASTER,
wait 60 seconds,
turn on MASTER,
turn on SLAVE,
and "pon".

If that doesn't work after three attempts,
2) turn off the instrument as in (1),
exit DetCom using "detach",
turn the instrument back on as in (1),
then restart DetCom.

If (2) doesn't work,
3) turn off the instrument as in (1),
exit DetCom as in (2),
then press the reset button (the white button next to the green LED) on the back of each of the two fiber optic communications cards on the back of the computer ("etna" or "vesuvius")
bring up the power on the instrument,
then start DetCom.

If (3) doesn't work,
4) turn off the instrument as in (1),
exit DetCom as in (2 or 3),
then turn off the acquisition computer (etna or vesuvius) by terminating all disk processes and pressing the "a" and "Stop" keys together then flipping the power switch at the boot prompt.
After 10 seconds, turn the computer back on by flipping the switch,
log in as "obs24m" or "obs13m",
bring up the power on the instrument,
then start DetCom.


If any of these procedures become necessary, successful or not, please contact Arlin Crotts ( to let him know the details.