Hi Emmanuel,
I have tried EPICS on cRIO but I am not satisfied with it. I do not like
that neither alarms nor time stamps are forwarded to EPICS. LabView and
EPICS communicate through a shared memory region which contains only
values and is processed by both sides with independent cycle rates.
So when your EPICS record is scanned ".1 second", you get a new
timestamp every 100 msec. But that does not mean that LabView has
updated the value in the meantime. Not even dream of "I/O Intr"
processing whenever LabView writes a new value.
Worse is that alarms are not handled. I looked into the LabView EPICS VI
and found that in fact if it gets an error input, it skips writing into
the shared memory! That means if something goes wrong on the LabView
side (e.g broken hardware) EPICS happily reads the last good value and
updates its timestamps. In my opinion the worst way you can deal with
faults.
I reported these problems to NI a long time ago. But since they seen not
able to do anything about this, I cancelled all NI related projects.
Dirk
On 19.09.2013 22:26, Emmanuel Mayssat wrote:
All,
While investigating high-level framework for EPICS, I came across the following page
http://digital.ni.com/public.nsf/allkb/BEF3C387D96E1A0C86257A3600508278
Is any one using LabView with EPICS?
What are the benefit of such a setup?
What are the drawbacks?
Regards,
--
Emmanuel
- References:
- LabView interface to EPICS Emmanuel Mayssat
- Navigate by Date:
- Prev:
RE: LabView interface to EPICS kathryn.baker
- Next:
Re: Generating a loadable module for cexp (epics 3.14.12.3) Till Straumann
- 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: LabView interface to EPICS kathryn.baker
- Next:
Generating a loadable module for cexp (epics 3.14.12.3) Sue Witherspoon
- 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
|