Re: timestampField not retrieved using CA provider for pvac::ClientChannel

["Bisegni, Claudio via Tech-talk" <tech-talk@aps.anl.gov>]

Hi yes sure:

 

This is my code:

 

auto ca_provider  = std::make_unique<pvac::ClientProvider>("ca", epics::pvAccess::ConfigurationBuilder().push_env().build());

auto  channel = std::make_shared<pvac::ClientChannel>(provider.connect(pv_name, opt));

auto op = channel->get(this, pvd::createRequest("field()"));

…

 

 

I need to specify that I connect to a IOCs launched with “sofIOC -d xyz.db” this si the content of the DB:

record(ao, "ca:variable:a")

{

    field(DRVH, "100")

    field(DOL, "0")

    field(PINI, "YES")

}

record(ao, "ca:variable:b")

{

    field(DRVH, "100")

    field(DOL, "0")

    field(PINI, "YES")

}

record(calc, "ca:variable:sum")

{

    field(SCAN, "1 second")

    field(INPA, "variable:a")

    field(INPB, "variable:b")

    field(CALC, "A+B")

}

 

I got this as answer on get operation:

 

structure

    double value 3

    alarm_t alarm

        int severity 0

        int status 0

        string message

    display_t display

        double limitLow 0

        double limitHigh 0

        string description

        string format F6.0

        string units

    control_t control

        double limitLow 0

        double limitHigh 0

        double minStep 0

    valueAlarm_t valueAlarm

        boolean active false

        double lowAlarmLimit nan

        double lowWarningLimit nan

        double highWarningLimit nan

        double highAlarmLimit nan

        int lowAlarmSeverity 0

        int lowWarningSeverity 0

        int highWarningSeverity 0

        int highAlarmSeverity 0

        byte hysteresis 0

 

 

From: Veseli, Sinisa <sveseli@anl.gov>
Date: Friday, 5 May 2023 at 11:05
To: Bisegni, Claudio <bisegni@slac.stanford.edu>, tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
Subject: Re: timestampField not retrieved using CA provider for pvac::ClientChannel

Hi,

 

I am not sure I understand what is going on. Perhaps you could include your code so we can see what exactly you are trying to do?

Also, if you'd like to get all fields, the string 'field()' or just empty string '' should work:

 

>>> print(c.get('field()'))

epics:nt/NTEnum:1.0

    enum_t value

        int index 0

        string[] choices [Off, On]

    alarm_t alarm

        int severity 0

        int status 0

        string message

    time_t timeStamp

        long secondsPastEpoch 1683129086

        int nanoseconds 834120910

        int userTag 0

 

 

--

Siniša Veseli

Scientific Software Engineering & Data Management

Advanced Photon Source

Argonne National Laboratory

sveseli@anl.gov

(630)252-9182

---

From: Bisegni, Claudio <bisegni@slac.stanford.edu>
Sent: Friday, May 5, 2023 12:56 PM
To: Veseli, Sinisa <sveseli@anl.gov>; tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
Subject: Re: timestampField not retrieved using CA provider for pvac::ClientChannel

 

I tried to set request field as:

pvd::createRequest("field(value, timeStamp, alarm, display, control, valueAlarm)

but I didn’t get the timeStamp Field in PVStructure. The request field work well for all other (for CA provider) for the PVA provider, instead, I always got every field also if I put only “filed(value)” in the request.

 

I’m wrong somenting….

 

Claudio

 

From: Bisegni, Claudio <bisegni@slac.stanford.edu>
Date: Friday, 5 May 2023 at 10:44
To: Veseli, Sinisa <sveseli@anl.gov>, tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
Subject: Re: timestampField not retrieved using CA provider for pvac::ClientChannel

Hi,

Thank you for yor help, is effect on get operation I use the default request, so Iat this point I need to use pvd::createRequest("field(value, timeStamp, alarm, display, control, valueAlarm)")); to retrieve all field

 

I’ll give a try!

 

Thank you very much.

 

Claudio

From: Veseli, Sinisa <sveseli@anl.gov>
Date: Friday, 5 May 2023 at 09:55
To: tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>, Bisegni, Claudio <bisegni@slac.stanford.edu>
Subject: Re: timestampField not retrieved using CA provider for pvac::ClientChannel

Hi,

 

I am not sure exactly why is there a difference in behavior between caget and pvget, but you should be able to get timestamps if you request them explicitly:

 

$ caget -a S01-DAQTBT:Strm:DataCaptureC

S01-DAQTBT:Strm:DataCaptureC   2023-05-03 10:51:26.834121 Off 

 

PV request string like field(value,timeStamp) should work from C++:

 

>>> from pvapy import *

>>> c = Channel('S01-DAQTBT:Strm:DataCaptureC', CA)

>>> print(c.get('field(value,timeStamp)'))

epics:nt/NTEnum:1.0

    enum_t value

        int index 0

        string[] choices [Off, On]

    time_t timeStamp

        long secondsPastEpoch 1683129086

        int nanoseconds 834120910

        int userTag 0

 

Hope this helps,

 

Sinisa

 

--

Siniša Veseli

Scientific Software Engineering & Data Management

Advanced Photon Source

Argonne National Laboratory

sveseli@anl.gov

(630)252-9182

---

From: Tech-talk <tech-talk-bounces@aps.anl.gov> on behalf of Bisegni, Claudio via Tech-talk <tech-talk@aps.anl.gov>
Sent: Friday, May 5, 2023 11:39 AM
To: tech-talk@aps.anl.gov <tech-talk@aps.anl.gov>
Subject: timestampField not retrieved using CA provider for pvac::ClientChannel

 

Hello EPICS tech,

I'm working with last epics release and I have notice that making a get operation for an IOC using a CA provider for crete a pvac::ClientChannel I don't receive the timestamp field:

 

I noticed that also the official caget has the problem:

 

developer@e058f4bc2090:/workspace$ pvget variable:sum

variable:sum 2023-05-05 16:34:54.607 3

developer@e058f4bc2090:/workspace$ caget variable:sum

variable:sum 3

 

so is a client library problem or a server or something else?

 

Thank

 

you in advance.

Claudio