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: EPICS Device Driver question
From: Andrew Johnson <[email protected]>
To: David Dudley <[email protected]>
Cc: [email protected]
Date: Tue, 31 Oct 2006 13:35:57 -0600
David Dudley wrote: 
Almost got the question entirely answered.  Just one more thing:
Once the initialize routine is executed, can additional records be
added?  For instance, can an additional I/O item by defined?  I'm not
giving access to change addresses, but can I also infer that you
can't add or delete any?

You can't run dbLoadRecords() after iocInit(), so you can't load any new records after initialization, and there is no infrastructure present to allow records to be deleted at runtime. Your "I/O item" would usually map to a record, so you are correct that nothing can be added or deleted after that dset->init(1) call.

If you actually want to be able to do something like that you can do it by implementing the Extended Device Support and loading a bunch of 'spare' records; when you need one you set its DTYP and INP/OUT field to the new Modbus address you want to talk to. You can't rename the record at runtime though, so this is not a perfect solution.

- Andrew
--
There is considerable overlap between the intelligence of the smartest
bears and the dumbest tourists -- Yosemite National Park Ranger
References:
Re: EPICS Device Driver question David Dudley
Navigate by Date:
Prev: Re: EPICS Device Driver question David Dudley
Next: Get new, improved Matlab CA support, and crash your IOC with put callbacks Kay-Uwe Kasemir
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 Device Driver question David Dudley
Next: Get new, improved Matlab CA support, and crash your IOC with put callbacks Kay-Uwe Kasemir
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, 02 Sep 2010 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·