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  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024  <2025 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  <2025
<== Date ==> <== Thread ==>

Subject: Re: Help with bumpless IOC reboot, record linking and initialization concepts
From: Marco Filho via Tech-talk <tech-talk at aps.anl.gov>
To: Michael Davidsaver <mdavidsaver at gmail.com>, "Johnson, Andrew N." <anj at anl.gov>
Cc: EPICS Tech Talk <tech-talk at aps.anl.gov>
Date: Fri, 19 Sep 2025 07:35:50 +0000
Ah, I think I didn't properly understand this email on the first read.

> Generally, I have found that the more effective way to coordinate connect/disconnect is at the driver level.  Generally with a special device support to drive on-connect processing.

You mean disconnecting from the actual equipment before the PVs are initialized and then only connecting once all the links are properly initialized?
If so, how do you detect at driver level that that has happened?

I can imagine connecting some record to a calcout INAV field and sending that value to the driver, but that only guarantees that that particular record is initialized, no?
Is there a better approach?

Marco

From: Michael Davidsaver <mdavidsaver at gmail.com>
Sent: Thursday, September 18, 2025 19:10
To: Johnson, Andrew N. <anj at anl.gov>
Cc: Marco Filho <marco.filho at ess.eu>; Ralph Lange <ralph.lange at gmx.de>; EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: Re: Help with bumpless IOC reboot, record linking and initialization concepts
 
On 9/18/25 07:54, Johnson, Andrew N. via Tech-talk wrote:
Many of our IOCs use one or more “dbpf” commands in their startup script (sometimes after an epicsThreadSleep) ...

Nooooooo!

Finding a bunch of random, rarely commented, dbpf calls in an IOC start script is to me a bad code smell.  The same goes for sleeps, only more so.  Please investigate 'field(PINI, "RUNNING")', or look at other ways to actually synchronize startup.


... it should even be possible to handle disconnections and later reconnections for links to remote IOCs if you want to do that.

imo. any well written driver for an ethernet attached device __needs__ to do this.

Generally, I have found that the more effective way to coordinate connect/disconnect is at the driver level.  Generally with a special device support to drive on-connect processing.



Replies:
Re: Help with bumpless IOC reboot, record linking and initialization concepts Michael Davidsaver via Tech-talk
References:
Re: Help with bumpless IOC reboot, record linking and initialization concepts Ralph Lange via Tech-talk
Re: Help with bumpless IOC reboot, record linking and initialization concepts Marco Filho via Tech-talk
Re: Help with bumpless IOC reboot, record linking and initialization concepts Johnson, Andrew N. via Tech-talk
Re: Help with bumpless IOC reboot, record linking and initialization concepts Michael Davidsaver via Tech-talk

Navigate by Date:
Prev: Re: Help with bumpless IOC reboot, record linking and initialization concepts Marco Filho via Tech-talk
Next: Re: Problem with drvAsynIPPortConfigure Dariush Hampai 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  <2025
Navigate by Thread:
Prev: Re: Help with bumpless IOC reboot, record linking and initialization concepts Maren Purves via Tech-talk
Next: Re: Help with bumpless IOC reboot, record linking and initialization concepts Michael Davidsaver 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  <2025