On Thursday 24 July 2014 11:27:24 Andrew Johnson wrote:
> On 07/24/2014 04:47 AM, Benjamin Franksen wrote:
> > On Thursday 24 July 2014 11:15:56 Dirk Zimoch wrote:
> >> On 21.07.2014 12:41, Benjamin Franksen wrote:
> >>> Why don't you just set DRVL=DRVH=<the desired value>.
> >>>
> >> /* check drive limits */
> >> if (prec->drvh > prec->drvl) {
> >>
> >> if (value > prec->drvh)
> >>
> >> value = prec->drvh;
> >>
> >> else if (value < prec->drvl)
> >>
> >> value = prec->drvl;
> >>
> >> }
> >>
> >> DRVL=DRVH => no check at all!
> >
> > Strange. Not intuitive to me. And contrary to the docs.
>
> That check predates the CVS history of the aoRecord.c file (1995). It
> makes perfect sense to me, there has to be a way to disable the
> clipping behaviour,
Hm, yes, that makes sense.
> and the assumption is that you would only create
> ao records for things that you want to be able to actually change.
In general, yes, but there are exceptions. I have used ao or ai records
to hold physical constants as parameters for a calculation. It would be
nice if I could tell the database to fix the value and not even allow a
db or ca put to change them. (One solution could be a simple record type
for such parameters. Maybe I'll write one when I have some leisure...)
> If
> you want to stop changes for a while, disable record processing using
> SDIS & DISV.
I don't think this will prevent the VAL from changing e.g. due to put
operations, or does it?
> > This is from the
> > RRM
> > (https://wiki-ext.aps.anl.gov/epics/index.php/RRM_3-14_Analog_Outpu
> > t#Desired_Output_Parameters):
> >
> > """
> > The VAL field's value is forced to be within the limits specified in
> > the fields DRVH and DRVL, which are configured by the designer:
> >
> > DRVL<=VAL<=DRVH
> >
> > Note: If nothing is entered for DRVH and DRVL, the output value will
> > never change.
> > """
>
> Wiki page fixed to document existing code.
Thanks.
Ben
--
"Make it so they have to reboot after every typo." â Scott Adams
________________________________
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
Mitglied der Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren e.V.
Aufsichtsrat: Vorsitzender Prof. Dr. Dr. h.c. mult. Joachim Treusch, stv. Vorsitzende Dr. Beatrix Vierkorn-Rudolph
Geschäftsführung: Prof. Dr. Anke Rita Kaysser-Pyzalla, Thomas Frederking
Sitz Berlin, AG Charlottenburg, 89 HRB 5583
Postadresse:
Hahn-Meitner-Platz 1
D-14109 Berlin
http://www.helmholtz-berlin.de
- Replies:
- Re: EPICS alarming on VAL != X Dirk Zimoch
- Re: EPICS alarming on VAL != X Andrew Johnson
- References:
- EPICS alarming on VAL != X Jameson Graef Rollins
- Re: EPICS alarming on VAL != X Benjamin Franksen
- Re: EPICS alarming on VAL != X Andrew Johnson
- Navigate by Date:
- Prev:
RE: Tabbed Container Ability Patard Charles-Henri
- Next:
Re: EPICS alarming on VAL != X Dirk Zimoch
- 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: EPICS alarming on VAL != X Andrew Johnson
- Next:
Re: EPICS alarming on VAL != X Dirk Zimoch
- 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
|