EPICS Home

Experimental Physics and Industrial Control System


 
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  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  <20112012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
<== Date ==> <== Thread ==>

Subject: RE: Alarm Handler and $ALARMCOUNTFILTER
From: <[email protected]>
To: <[email protected]>
Date: Thu, 21 Jul 2011 10:45:25 +0000
Thanks, Andrew.
You haven't corrected my understanding of how the $ALARMCOUNTFILTER behaves so at least I know I'm not missing some trick. I'll just have to work with it as it is, or like you say, implement an alternative in the IOC.
I was partly after confirmation that other people are happy with the way things are. Since you're using this feature a lot at ALH it clearly suits your needs.
I may risk proposing some backward compatible changes in the future, but this will take effort and it looks like I'm the only one who needs them.
Regards,
Keith.

-----Original Message-----
From: Andrew Johnson [mailto:[email protected]] 
Sent: 18 July 2011 17:14
To: [email protected]
Cc: Baker, Keith (DLSLtd,RAL,DIA)
Subject: Re: Alarm Handler and $ALARMCOUNTFILTER

Hi Keith,

On 2011-07-18 [email protected] wrote:
> 
> My requirement is to only register an alarm if the value exceeds the
>  threshold persistently for 120 seconds.
...
> The other behaviour I've noticed is that once in alarm, the same criteria
>  is used to decide when to drop down to no alarm. i.e. if the PV value
>  drops below the threshold then it takes inputSeconds before this is
>  recognised, or inputCount drops within inputSeconds. I am just curious as
>  to whether this is behaviour that anybody wants or uses? I'd prefer to
>  drop out of the alarm state immediately.

It's likely that the behaviour implemented was required by someone at APS when 
we wrote ALH, I see it being used fairly heavily in our operational alhConfig 
files.

I would suggest that your alarm filter should probably be implemented inside 
the IOC, rather than rely on ALH to do it.  It's much easier to customize 
there anyway.

- Andrew
-- 
Optimization is the process of taking something that works and
replacing it with something that almost works, but costs less.
-- Roger Needham

-- 
This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail.
Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. 
Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message.
Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
 





References:
Alarm Handler and $ALARMCOUNTFILTER keith.baker
Re: Alarm Handler and $ALARMCOUNTFILTER Andrew Johnson

Navigate by Date:
Prev: Re: Does EPICS Base support multi-thread on vxWorks 6.3? lorna . zhang
Next: RE: Areadetector: driver for Amptek X-123 (DP5) Mark Rivers
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
Navigate by Thread:
Prev: Re: Alarm Handler and $ALARMCOUNTFILTER Andrew Johnson
Next: Re-release pcas as pcaspy Wang Xiaoqiang
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024