Re: C++ multi threaded application.

[Ralph Lange <ralph.lange@gmx.de>]

Ciao Giacomo,

On Wed, Sep 6, 2017 at 10:02 AM, Giacomo S. <giacomo.strangolino@elettra.eu> wrote:

A typical graphical interface wants to put in evidence warning or alarm
values (for example, in a gauge you want yellow or red bands or you may
want coloured stripes on the background of a plot in the alarm or
warning sections), so, in this case I may be interested in two kind of
subscriptions:

- the DBE_PROPERTY to get alarms. LO/HI thresholds, display and so on...
- the DBE_VALUE to get value changes.

Well, almost. Typically, you would subscribe

• to the full structure (DBR_CTRL_...) using the DBE_PROPERTY flag to get updates on the limits and thresholds,
  
• to a small value/status(/timestamp) structure (DBR_STS_... or DBR_TIME_...) using DBE_VALUE | DBE_ALARM to get value and status updates (with timestamps).
  

It would be very useful to me a kind of documentation where this is
described.
I'll have a look at your link now.

Other than the Channel Access Reference Manual (available on the EPICS web site, e.g. http://www.aps.anl.gov/epics/base/R3-15/5.php), the CA client example (makeBaseApp template), the CA command line tools (that you already found) and the training slides that Andrew pointed out, I don't know of any CA client usage documentation. Sorry!

Cheers,
~Ralph