NATIONAL RADIO ASTRONOMY OBSERVATORY
MEMORANDUM
DATE: December 9, 1993
TO: 140-ft operators
FROM: Ron Maddalena
SUBJECT: Some changes in MacII and Sun procedures.
We have been running the new archive system for the last few months and I
would like to make the following changes to the procedures you have been
following. Some of these things you are already doing but I'd like to formalize
these thoughts for you. Perform all steps in the order given--the order of the
steps is as important as the actions involved.
Before making an archive tape, please do the following:
Stop taking data
Perform a DUMMY calibration observation (i.e., a CAL scan with DUMMY as a source name).
Start the dumping of the archive.
After the archive program says that it is "dumping" the archive, you can start taking data again.
Continue with the instructions below for Case 3.
If you don't perform these steps properly, occasionally data might not make
it onto the archive tape.
If you or any other staff member need to shut down the MacII or Sun (e.g., if someone is about to do a backup, there will be a planned power outage, hung processes, etc.), you should do the following:
Stop taking data.
Perform a DUMMY calibration observation (i.e., a CAL scan with DUMMY as a source name).
Shut down the computer using the instructions in my previous memo.
Continue with the instructions below for Case 3.
Don't let staff or observers shut down the computer without first preforming
these steps. Most staff are unaware that these precautions need to be taken.
Only Nancy or I are aware of when these instructions shouldn't be followed (and
the cases are not easily described and are few). Remember, the operators and
staff intimately involved with the 140-ft must take responsibility for when the
Sun or MacII are to be rebooted. Other staff members and astronomers must adhere
to your decisions.
After any instance in which the Sun or MacII are rebooted, or after an archive tape has been made, or at the end of maintenance day, you should:
Make sure MacII and Sun communication is up (i.e., no error messages every few seconds on either machine). See Case 4 if the communications doesn't seem to want to start up properly.
Perform a few DUMMY calibration observation (i.e., a CAL scan with DUMMY as a source name).
The first or second DUMMY scan may not make it across. If so, wait until communications re-establish themselves and try again.
If after the third or forth try data is still not getting across to the Sun without an error message, try to follow the steps in Case 4.
If two or more scans get across OK, start taking data.
If you don't perform these steps, data is being lost!!
If the Sun and MacII link fails to restart itself properly and you keep
getting error messages every few seconds for a few minutes on either the Sun or
MacII, try the following:
Shutdown the MacII.
Shutdown the Sun.
Reboot MacII and wait until it has completely come up.
Reboot the Sun and wait for it to completely come up.
If things still give you trouble, call for help, else start taking data.
If you are getting CHECKSUM or SYNC BIT errors on the MacII, the problem lies
in the Modcomp and MacII link and has nothing to do with the Sun. Errors of this
type are displayed on the MacII screen and are designated by the messages
1*error, 2*error, 3*error, or 4*error where the '*' indicates a lower-case
letter (e.g., 4cerror). If you see these error messages, sit back and see if
they continue with the next record. If they persist, do the following:
Reboot the Modcomp and try to take data.
If problems persist, reboot MacII, wait for communications to re-establish themselves, and start taking data.
Call for help if even after rebooting MacII and Modcomp the problem continues.