View source for Epics Logger Scripts for SBS

Here is some technical information about how to add EPICS variables to
the logging of information for the SBS.

== How to Add Variables to EPICS logging for SBS ==

<pre>
1. Edit EpicsToFile, add your variable.
2. Might want run this with TESTPRINT=1 and run EpicsToFile interactively to check it.  Don't forget to restore TESTPRINT=0.
3. Kill the current running of EpicsToFile

[sbs-onl@adaq1 halla]$ ps awx | grep EpicsToFile
 4018 pts/69   S+     0:00 grep --color=auto EpicsToFile
10161 ?        S      1:03 /bin/ksh /adaqfs/home/sbs-onl/logentry_scripts/halla//EpicsToFile

kill -9 10161

4. Then wait.  The cron script "startCron" will restart it in a few minutes.  Perhaps check the process list to be sure.
</pre>
One fly in the ointment at the moment is that if someone is doing "less EpicsToFile" or "more EpicsToFile"
on adaq1, then unfortunately startCron is not smart enough to restart EpicsToFile.  It is smart enough
to ignore emacs sessions.  For this case, kill the "less" command, too.

<pre>
[sbs-onl@adaq1 halla]$ ps awx | grep EpicsToFile
 2312 pts/69   T      0:00 less EpicsToFile
 3034 pts/69   S+     0:00 grep --color=auto EpicsToFile
10161 ?        S      1:04 /bin/ksh /adaqfs/home/sbs-onl/logentry_scripts/halla//EpicsToFile

kill -9 2312
kill -9 10161

</pre>

== Explaining the EPICS logging scheme for SBS ==

The EPICS data go to two places

1. HALOG -- both start-of-run and end-of-run.

2. datastream as event type 131

Let me describe the scheme.

A script called EpicsToFile runs continuously, using caget to obtain EPICS
variables and put them into text files.

<pre>
File to log EPICS data
/adaqfs/home/sbs-onl/logentry_scripts/halla/EpicsToFile
</pre>

the text files are in 
/adaqfs/home/sbs-onl/logentry_scripts/halla/epics/halla.epics

Note, halla1.epics is rewritten frequently while halla.epics is a more stable copy
that gets put into HALOG and datastream.

For the HV, its similar.  A script
/adaqfs/home/sbs-onl/logentry_scripts/HV_logging_SBS/EpicsLooper
with data in the /Results subdirectory.

Other scripts insert the halla.epics file into the datastream
and into the HALOG.

All the scripts mentioned are in the directory
/adaqfs/home/sbs-onl/logentry_scripts/halla/

<pre>
InsertETLoop -- loops forever, puts halla.epics into ET system
as event type 131

getruninfo_bgr_SBS -- inserts EPICS data into HALOG.

and getruninfo_bgr_SBS is called by start_run_SBS at the start of a run
and by end_run_SBS at the end of the run.
</pre>