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: stale data monitor
From: "Redman, Russell O." <[email protected]>
To: "'Vladimir Sirotenko'" <[email protected]>, [email protected]
Date: Wed, 10 Sep 2003 13:58:59 -0700
One possible way would be to construct a delay line of ai records, say delay0, delay1 and delay2, and a calc record.  Set their input links
   delay0.INP = (hardware)
   delay1.INP = delay0 NPP
   delay2.INP = delay1 NPP
   calc.INPA = delay0 NPP
   calc.INPB = delay1 NPP
   calc.INPC = delay2 NPP
and their forward links
   delay0.FLNK = calc
   delay1.FLNK = delay0
   delay2.FLNK = delay1
Processing starts with delay2 which gets its new value from the current value of delay1, then causes delay1 to process.  Delay1 gets its new value from the current value of delay0, then causes delay0 to process.  Delay0 gets its new value from the hardware, then causes the calc record to process and compare the three values.  Initializing the chain might be a bit of a chore, however. 
 
If you need to do this in more than one place, this purely EPICS solution is not likely to be the best solution.  It is a bit more of a fuss to configure, but it would probably be easier in the long run to write a few lines of C code to put into a subr or gensub record. 
Cheers,

Dr. Russell O. Redman
Tel: (250) 363-6917 | Fax: (250) 363-0045
<mailto:[email protected]>
National Research Council Canada | Conseil national de recherches Canada
5071 West Saanich Road           | 5071 West Saanich Road
Victoria, B. C. V9E 2E7          | Victoria, C.-B. V9E 2E7
Government of Canada             | Gouvernement du Canada

-----Original Message-----
From: Vladimir Sirotenko [mailto:[email protected]]
Sent: Wednesday, 2003 September 10 12:24 PM
To: [email protected]
Subject: stale data monitor

Hi,
 
Is there easy and natural way to monitor stale data from, say, ai record just using EPICS records? For example, I have to send alarm when several consecutive reading return the same value. The time interval for those consecutive reading may be rather large, of the order of minutes. If it would be shorter, I could use seq record with delays, but for several minutes interval how can I trigger its processing?
 
Thanks,
Vladimir
 
Replies:
Re: stale data monitor Bob Dalesio
Navigate by Date:
Prev: stale data monitor Vladimir Sirotenko
Next: Epics / OS-X Matthieu Bec
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: stale data monitor Vladimir Sirotenko
Next: Re: stale data monitor Bob Dalesio
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, 10 Aug 2010 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·