Experimental Physics and
Industrial Control System

Benjamin Franksen <[email protected]> · Wed, 11 Mar 2015 21:42:30 +0100

I guess the idea is to make a record type that can be processed multiple times
and fire the put callback only if specific conditions are met, i.e. some
action (involving perhaps more than one record) have finished. Something like
the motor record.

This can indeed be done with a busyRecord and asynchronous out links, but
depending on what exactly is the desired functionality can be difficult to get
right. I can try and dig out the database I once designed for that purpose.

Cheers
Ben

Am Mittwoch, 11. März 2015, 19:01:12 schrieb Mooney, Tim M.:
> Hi Dehong,
>
> I don't understand.  All the EPICS records I've used behave correctly when
> written to by a ca_put_callback, whether they use synchronous or
> asynchronous device support.  Are you writing a new record type, or trying
> to get asynchronous device support to work with an existing record type, or
> what?
>
> Tim Mooney ([email protected]) (630)252-5417
> Software Services Group (www.aps.anl.gov)
> Advanced Photon Source, Argonne National Lab
>
> ________________________________
> From: [email protected] [[email protected]] on
> behalf of Zhang, Dehong [[email protected]] Sent: Wednesday, March
> 11, 2015 1:48 PM
> To: [email protected]
> Subject: Please help with "caput -c"
>
>
> Hi Friends,
>
>
> I am trying to implement an asynchronous record, would like to support
>
> this "put callback" feature.  From the documentation, it seems I have to do
>
> the following:
>
>
> 1. set "pp(TRUE)" for the field the user is going to "caput"
>
> 2. make sure only call "recGblFwdLink" (within "process") when the action is
>
>     finished, or use a BUSY record in the end of the FLNK chain such that it
>
>     is "DONE" only when the action is finished.  -- during this process the
> PACT
>
>     field of the original record can go up and down.
>
>
> I have been playing with all these combinations, and by adding "-w **" after
>
> the "caput -c", am getting inconsistent and unreliable results -- it either
> does
>
> not work - calls back immediately, or waits unnecessarily long then calls
> back.
>
> It rarely calls back right after the original record finishes processing and
> declares
>
> the action is finished.  Guess I missed something.  Please spare a few
> moments
>
> and advice on what exactly I need to do.
>
>
> (We use 3.14.12-0.4.0, on linux machines).
>
>
> Thank you very much, Best regards,
>
> Dehong

--
"There are two ways of constructing a software design: One way is to
make it so simple that there are obviously no deficiencies and the other
way is to make it so complicated that there are no obvious deficiencies.
The first method is far more difficult."   ― C.A.R. Hoare

________________________________

Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

Mitglied der Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren e.V.

Aufsichtsrat: Vorsitzender Prof. Dr. Dr. h.c. mult. Joachim Treusch, stv. Vorsitzende Dr. Beatrix Vierkorn-Rudolph
Geschäftsführung: Prof. Dr. Anke Rita Kaysser-Pyzalla, Thomas Frederking

Sitz Berlin, AG Charlottenburg, 89 HRB 5583

Postadresse:
Hahn-Meitner-Platz 1
D-14109 Berlin

http://www.helmholtz-berlin.de

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System