Re: pvGet in Sequence does not work with incorrect size

[Simon Reiter via Tech-talk <tech-talk@aps.anl.gov>]

Ok,

This problem solve itself.

PVs were provided by a gateway with EPICS_CA_MAX_ARRAY_BYTES slightly
too low in the same network. Depending on which PVs was connected in
the sequence, it either worked or not.

Maybe this helps someelse in the future ;)

Cheers,
Simon


On Mon, 2019-09-02 at 16:06 +0200, Simon Reiter via Tech-talk wrote:
> Hi Ben,
> 
> Since monitoring work back then, I could live with that.
> 
> But I am facing a new/similar problem right now. There seems to be a
> problem also for monitored PVs. This time the array size is 262144.
> 
> Earlier pvGet() always resulted in a timeout. But now this happens
> only
> for some modules. The sequence is running in parallel for 5 modules
> right now. 2 of them are fine, 2 not. Sometime it changes after minor
> (logging) changes in the code. So I already assumed some memory
> problem, but I am not sure how to handle.
> 
> So I have to scenarios:
> - pvGet run into timeout
> - all entries of monitored PV are zero
> 
> What are the reasons, a pvGet runs into a timeout at all? I check in
> the previous condition that the PV is connected.
> 
> Cheers,
> Simon
> 
> PS: Currently running with EPICS 3.16.
> 
> 
> 
> On Wed, 2019-07-17 at 12:42 +0200, Benjamin Franksen wrote:
> > Am 16.07.19 um 16:43 schrieb Simon Reiter via Tech-talk:
> > > using the sequencer in v2.2 and EPICS 3.14:
> > > 
> > > The sequence does get a waveform, does a calculation and pushes
> > > an
> > > array out to another waveform PV.
> > > 
> > > pvGet() is not working and runs in a timeout in case the size of
> > > the
> > > unsigned char array does not exactly fit the size of the
> > > waveform.
> > > 
> > > Instead, assigning and monitoring the PV in the beginning works
> > > fine.
> > > Is this on purpose? The monitoring of the is not necessary.
> > 
> > Hi Simon
> > 
> > This should not happen. I will try to reproduce your problem and
> > add
> > a
> > test case. Dealing with arrays in EPICS is awfully hard, so I guess
> > it's
> > quite possible that this is a bug in the Sequencer.
> > 
> > Cheers
> > Ben
> > 
> 
>