Re: Dynamic Listing of PVs

[Ralph Lange <Ralph.Lange@bessy.de>]

Not quite as simple as it sounds.

The pvlistserver depends on the EPICS database on an IOC being static 
and well-defined.

A CAS can practically sit on top of anything: e.g. a single server 
(IOC), a known set of servers (Gateway to my known network), an unknown 
set of servers (Gateway to the outside world), a service that creates 
PVs on the fly.
What should such a "get the list of PVs" function return, in cases when
o the number of PVs is very large (Gateway to the outside world)
o the PVs are unknown, because they are only connected to on demand 
(any Gateway)
o the PVs can never be known, because they are dynamically created by 
asking for them (on-demand PV server)

Compare this to asking your gateway router which IPs it would provide 
access to...

I agree with Bob that this issue is probably to be handled outside the 
Channel Access domain. And still for some servers there is no finite list.

Ralph


On 24.02.2009 00:26 Bruno Coudoin wrote:
> Le lundi 23 février 2009 à 14:19 -0800, Ernest L. Williams Jr. a écrit :
>   
> > Bruno Coudoin wrote:
> >     
> > > >From a Channel Access client, is there a way to dynamically get the list
> > > of PVs exported by an IOC or a CAS?
> > >
> > >   
> > >       
> > Hi Bruno,
> >
> > John Sinclair from SNS created a nice tool for this.
> > http://ics-web.sns.ornl.gov/pvlistserver/log/show.php?mon=Jan&theDay=5&year=2004
> >
> > I hope to have it working under RTEMS as well:
> >
> >     
>
> Hum, I see. Did anybody started an implementation for a CAS ?
>
> Bruno.
>
>