EPICS Controls Argonne National Laboratory

Experimental Physics and
Industrial Control System

1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  <20092010  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  <20092010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
<== Date ==> <== Thread ==>

Subject: FW: EPICS Python client application survey
From: <[email protected]>
To: <[email protected]>
Date: Thu, 1 Oct 2009 16:59:03 +0100
Sorry, again this was meant to be CC'd to the list.


From: Andrew Johnson [mailto:[email protected]] 
> On Thursday 01 October 2009 05:16:53 Michael Abbott wrote:

> > 3. What happens if I ask for a PV name ending in $ on a pre 
> 14.11 server?
> > In particular, can I safely just hard-wire the special "ends with $ turns
> > into a string" treatment, or is this going to cause backwards
> > compatibility pain?
> 
> Please do *not* look at the PV name in your code, there may 
> be other field modifiers in the future that will also 
> generate a string as a DBF_CHAR array, and existing 
> applications already use waveform records to store long text 
> strings (MEDM and EDM have both supported this for many years).
> 
> You need to decide how to handle the data based on ca_field_type(), 
> ca_element_count() and whether the application is looking for 
> a string or an array of numbers.  Unfortunately the last part 
> is essential, only the application developer knows whether the 
> aSub.VALA field is supposed to hold a printable string or a pixel array.

Huh.  I think you're not going to like my Python channel access solution then.


-- 
Our IT guys are playing with the disclaimer below.  I dread to think what it looks like today.

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --    
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
 



Navigate by Date:
Prev: Re: EPICS Python client application survey Andrew Johnson
Next: Re: state notation code flags Patrick Thomas
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  <20092010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
Navigate by Thread:
Prev: Re: EPICS Python client application survey Matt Newville
Next: Re: EPICS Python client application survey Darren Dale
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  <20092010  2011  2012  2013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
ANJ, 31 Jan 2014 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·