Experimental Physics and
Industrial Control System

Jameson Graef Rollins <[email protected]> · Wed, 25 Mar 2015 09:38:15 -0700

On Wed, Mar 25 2015, Dirk Zimoch <[email protected]> wrote:
> On 25.03.2015 04:46, Matt Newville wrote:
>> Yes, I think this idea of getting the ctrl variables in the connection
>> callback is a good idea, and will allow more straightforward code  As it
>> is, a pyepics.PV is already expected to be a "rich" object, even if
>> sacrificing ultimate performance, and is normally expected to have the
>> ctrl variables.   So, I think it's reasonable to have this getting of
>> ctrl variables as the default.    I'll add that.
>
> This is generally a good idea for every ca client. After a reboot, 
> anything may have changed: Enum strings, limits, units, precision, array 
> size, even record type (and thus data type).

This is actually a really good point.  We employ a lot of PCAS with enum
records whose string mappings change fairly regularly.  The fact that
none of our CA clients ever know about these changes until the operator
manually restarts them has actually been quite problematic for us.  If
the clients would always refresh their ctrl records after new
connections, things would be much more robust.

jamie.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System