[Halld-online] question about scalers in the EPICS archiver

[Richard Jones]

Hello Hovanes and all,

I am accessing the GlueX scalers in the EPICS archive using the MYA
interface, and have run into a question. I am looking at a variable
like TAGM:T:8:scaler_t1
whose name suggests that it is the discriminator scaler for TAGM column 8.
When I look at the numbers in that variable, they are obviously not
scalers. They are non-integer values in the range of 3000-8000 for the runs
that I am looking at. Are they rates? In what units? kHZ? What is the
sampling interval? This matters because of statistical error. I see entries
in there sometimes separated by tens of seconds during a run. In the time
between the samples, were the scalers free-running so that I have the full
statistical information in the one reading at the end of the interval, or
are all of the statistics during the seconds in between the records in the
DB lost?

-Richard J.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/halld-online/attachments/20180111/a1ea86bb/attachment.html>