EPICS Home EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

Format page
for printing


Search Tech-talk
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
<== Date ==> <== Thread ==>
Subject: Re: Waveforms in Archiver Appliance
From: John Dobbins via Tech-talk <tech-talk at aps.anl.gov>
To: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Date: Thu, 21 Apr 2022 18:02:30 +0000
In Matlab I am doing

pv = 'S7B1_VER'
start_time = '2022-04-21T13:15:00.000Z'
end_time  = '2022-04-21T13:15:10.000Z'

 urlwrite('http://archive-chess.classe.cornell.edu/retrieval/data/getData.mat', ...
         'temp.mat', 'get', ...
         {'pv',pv, 'from', start_time, 'to', end_time});

but the temp.mat file I get back is empty.

In the archiver Appliance details for this PV:

PV Name                            S7B1_VER
Instance archiving PV              appliance0
Archival params creation time:     Apr/21/2022 12:05:35 -04:00
Archival params modification time: Apr/21/2022 12:05:35 -04:00
Archiver DBR type (from typeinfo): DBR_WAVEFORM_DOUBLE
Is this a scalar:                  No
Number of elements:                50
Precision:                         0.0
Units:
Is this PV paused:                 No
Sampling method:                   MONITOR
Sampling period:                  1.0
Are we using PVAccess?            No
Extra info - SCAN:                Passive
Extra info - RTYP:                waveform
Channel Name                      S7B1_VER
Host name                         chess62.classe.cornell.edu
Controlling PV
Is engine currently archiving this?  yes
Archiver DBR type (initial)       DBR_WAVEFORM_DOUBLE
Archiver DBR type (from CA)       DBR_WAVEFORM_DOUBLE
Number of elements per event (from CA) 50
Is engine using monitors?            yes
What's the engine's sampling period? 1.0
The SCAN period (ms) after applying the jitter factor 0
Is this PV currently connected?      yes
Connection state at last connection changed event Not connected
When did we receive the last event? Apr/21/2022 13:51:48 -04:00
What did we last push the data to the short term store? Apr/21/2022 13:51:46 -04:00
When did we request CA to make a connection to this PV? Apr/21/2022 12:05:55 -04:00
When did we first establish a connection to this PV? Apr/21/2022 12:05:55 -04:00
When did we last lose and reestablish a connection to this PV? Apr/21/2022 12:21:25 -04:00
When did we last lose a connection to this PV? Never
How many times have we lost and regained the connection to this PV? 1
How many events so far? 5425
How many events lost because the timestamp is in the far future or past so far? 0
Timestamp of last event from the IOC - correct or not. Apr/21/2022 13:51:48 -04:00

Any thoughts?

John

From: John Dobbins <john.dobbins at cornell.edu>
Sent: Thursday, April 21, 2022 12:20 PM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: Waveforms in Archiver Appliance
 
What is the easiest way to get this data (waveforms) out of the archiver?

John
From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of John Dobbins via Tech-talk <tech-talk at aps.anl.gov>
Sent: Thursday, April 21, 2022 12:14 PM
To: Michael Davidsaver <mdavidsaver at gmail.com>
Cc: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: Waveforms in Archiver Appliance
 
Michael ,

It turned out to be the array size/EPICS_CA_MAX_ARRAY_BYTES.   I was only putting 50 values in the array but NELM =2048. Reducing NELM fixed the problem.

Also, thanks for the pointer to the policies info. I was wondering about that.

John

From: Michael Davidsaver <mdavidsaver at gmail.com>
Sent: Thursday, April 21, 2022 12:07 PM
To: John Dobbins <john.dobbins at cornell.edu>
Cc: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: Waveforms in Archiver Appliance
 
On 4/21/22 06:47, John Dobbins via Tech-talk wrote:
> All,
>
> Does the EPICS Archiver Appliance accept waveforms? The documentation suggests it does, but I was unable to add one (after initial sampling its status is 'not being archived').

You may be running afoul of a policy condition.

cf. the default policy.

https://github.com/slacmshankar/epicsarchiverap/blob/master/src/sitespecific/slacdev/classpathfiles/policies.py


> Thanks,
>
> John Dobbins
>
> Research Support Specialist
> Cornell High Energy Synchrotron Source
> Cornell University
>
> www.chess.cornell.edu <http://www.chess.cornell.edu>
>
>
>
>

Replies:
Re: Waveforms in Archiver Appliance John Dobbins via Tech-talk
References:
Waveforms in Archiver Appliance John Dobbins via Tech-talk
Re: Waveforms in Archiver Appliance Michael Davidsaver via Tech-talk
Re: Waveforms in Archiver Appliance John Dobbins via Tech-talk
Re: Waveforms in Archiver Appliance John Dobbins via Tech-talk
Navigate by Date:
Prev: RE: [EXTERNAL] Re: Getting Permission denied messages while building Barrett (US), Patrick E via Tech-talk
Next: Re: Waveforms in Archiver Appliance John Dobbins via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
Navigate by Thread:
Prev: Re: Waveforms in Archiver Appliance John Dobbins via Tech-talk
Next: Re: Waveforms in Archiver Appliance John Dobbins via Tech-talk
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  <2022>  2023  2024 
ANJ, 14 Sep 2022 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·