Experimental Physics and
Industrial Control System

[email protected] (Bob Dalesio) · Wed, 17 Nov 1999 01:16:20 -0700

The channel archiver was not meant as areplacement for SDDS. The
toolset available in SDDS is more inline with Matlab, IDL, or
other analysis tools. The channel archiver is meant to save data
over time at the rate that the process can produce it - or at some
rate that the facility wishes to keep it. I was under the impression
that the SDDS data logging facility was somewhat rate limited to
1 Hz and that it was impracticle for saving Giga bytes of data over
long periods of time. Is this so? In any case, it would be a worthwhile
addition to the viewers available for the channel archiver to be able
to produce SDDS format data in addition to the spreadsheet format that
they already produce. There are currently three data viewers that are
available in Beta release - xarr (unix/Motif), a windows NT plot similar
to xarr, and a cgi server that runs through a browser. The latest version
of the channel archiver, written by Kay Kasemir, runs under either UNIX
or Windows and was tested on a Pentium 450 MHz PC collecting near 10K
signals per second. At 10K, there is some loss due to channel access flow
control being automatically turned on when the archiver is busy writing
the data to disk.

Could someone please clarify the data rates for SDDS logging?

	Thanks,
	Bob

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System