Re: monitors on array variables

["D. Peter Siddons via Tech-talk" <tech-talk@aps.anl.gov>]

Hi Michael,

   I tried that and it didn't change anything. However, I discovered that accessing some variables from the iocsh gave different results from caget, so I must have some name confusion in my code. Thanks for your help, at least I discovered this!

Pete.

On 3/18/20 6:25 PM, Michael Davidsaver wrote:

> FYI. passing NULL instead of a field address to db_post_events()
> will post to every subscription on the record regardless of field.
> Trying this should give a clear indication if the only problem is
> the wrong field address.
>
> I guess the other variable is event mask.  SO
>
> > db_post_events(pscal,NULL,0xf);
> >       
> should post to every subscriber to this record regardless of field or mask.
>
>
> On 3/18/20 12:02 PM, Mark Rivers wrote:
> > Could this be a problem with EPICS_CA_MAX_ARRAY_BYTES?  What if you do:
> >
> >
> > camonitor -#20  det1.SPCT
> >
> >
> > ________________________________
> > From: Siddons, David <siddons@bnl.gov>
> > Sent: Wednesday, March 18, 2020 1:51 PM
> > To: Mark Rivers; Michael Davidsaver
> > Cc: EPICS Tech-Talk
> > Subject: Re: monitors on array variables
> >
> > Hi Mark,
> > Yes, I did that. THis is essentially an expanded scaler record. In updateCounts I have:
> >
> >         Debug(5, "updateCounts: posting scaler values %d\n",0);
> >         /* copy and post spectrum values */
> >         for (i=0; i<4096; i++) {
> >                 if (mca[4096*pscal->monch+i] != spct[i]) {
> >                       spct[i]=mca[4096*pscal->monch+i];
> >                       }
> >          }
> >          db_post_events(pscal,&pscal->mca,DBE_VALUE);
> >          db_post_events(pscal,&pscal->tdc,DBE_VALUE);
> >          db_post_events(pscal,&pscal->spct,DBE_VALUE);
> >
> > etc,
> >
> > It gives this output:
> > ../zDDMRecord.c(818):updateCounts:   called by process()
> > ../zDDMRecord.c(830):updateCounts: got counts[] 0
> > ../zDDMRecord.c(838):updateCounts: posting scaler values 0
> > ../zDDMRecord.c(866):updateCounts: exit 0
> >
> > Running camonitor on det1.SPCT reads the initial values and waits. Triggering a change (by changing monch) results in nothing. It just sits there. I can verify that the values have changed by doing a caget, or a dbgf on the console:
> >
> > peter@peter-Latitude-E7240: ~/$ caput det1.MONCH 0
> > Old : det1.MONCH                     5
> > New : det1.MONCH                     0
> > peter@peter-Latitude-E7240: ~/$ caget det1.SPCT[1:20]
> > det1.SPCT[1:20] 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
> > peter@peter-Latitude-E7240: ~/$ caput det1.MONCH 5
> > Old : det1.MONCH                     0
> > New : det1.MONCH                     5
> > peter@peter-Latitude-E7240:~/$ caget det1.SPCT[1:20]
> > det1.SPCT[1:20] 20 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
> >
> >
> > I guess I'm doing something dumb, but I can't see it.
> >
> > Pete.
> >
> >
> >
> >
> > ________________________________
> > From: Mark Rivers <rivers@cars.uchicago.edu>
> > Sent: Wednesday, March 18, 2020 2:25 PM
> > To: Siddons, David <siddons@bnl.gov>; Michael Davidsaver <mdavidsaver@gmail.com>
> > Cc: EPICS Tech-Talk <tech-talk@aps.anl.gov>
> > Subject: Re: monitors on array variables
> >
> > Can you put some debugging to be sure db_post_events is actually being called, while at the same time running camonitor to see if gets an update?
> >
> >
> >
> > ________________________________
> > From: Siddons, David <siddons@bnl.gov>
> > Sent: Wednesday, March 18, 2020 1:09 PM
> > To: Michael Davidsaver; Mark Rivers
> > Cc: EPICS Tech-Talk
> > Subject: Re: monitors on array variables
> >
> > .....and I have, in cvt_dbaddr():
> >
> >   case zDDMRecordSPCT:{
> >       paddr->pfield = (void *)(pzDDM->pspct);
> >       paddr->no_elements = 4096; /* One spectrum for real-time display */
> >       paddr->field_type = DBF_LONG;
> >       paddr->field_size = sizeof(int);
> >       paddr->dbr_field_type = DBR_LONG;
> >       break;
> >
> >
> > Pete.
> >
> >
> > ________________________________
> > From: Michael Davidsaver <mdavidsaver@gmail.com>
> > Sent: Wednesday, March 18, 2020 12:54 PM
> > To: Mark Rivers <rivers@cars.uchicago.edu>; Siddons, David <siddons@bnl.gov>
> > Cc: EPICS Tech-Talk <tech-talk@aps.anl.gov>
> > Subject: Re: monitors on array variables
> >
> > On 3/18/20 9:47 AM, Mark Rivers wrote:
> > > > by analogy waveformRecord has
> > > > > db_post_events(prec, &prec->val, monitor_mask);
> > > > >             
> > > > note 'val' not 'bptr'.
> > > >           
> > > The mca record has worked with no changes in 3.14, 3.15, and 7.0.3 with these lines:
> > >
> > >
> > > mcaRecord.dbd:
> > > recordtype(mca) {
> > >         include "dbCommon.dbd"
> > >         field(VERS,DBF_DOUBLE) {
> > >                 prompt("Code Version")
> > >                 special(SPC_NOMOD)
> > >                 initial("1")
> > >         }
> > >         field(VAL,DBF_NOACCESS) {
> > >                 prompt("Value")
> > >                 special(SPC_DBADDR)
> > >                 pp(TRUE)
> > >                 size(4)
> > >                 extra("void *val")
> > >         }
> > >         field(BPTR,DBF_NOACCESS) {
> > >                 prompt("Buffer Pointer")
> > >                 special(SPC_NOMOD)
> > >                 interest(4)
> > >                 size(4)
> > >                 extra("void *bptr")
> > >         }
> > >
> > > mcaRecord.c:
> > >     if (MARKED(M_VAL)) db_post_events(pmca,pmca->bptr,monitor_mask);
> > >
> > > So it is posting monitors on the bptr field, not the val field, and it seems to work fine.
> > >
> > >
> > > It looks like Pete is doing what the mca record does, but it is not working.  Why?
> > >         
> > Ah, there is a second piece to the puzzle.
> >
> > db_post_events() must be called with whatever address is in DBADDR::pfield
> > which by default in this case is '&val' but this can be changed in the
> > cvt_dbaddr callback.  Indeed waveformRecord used to do this.
> >
> > https://github.com/epics-base/epics-base/commit/92d52cc415599b7dffa7df1f23d5ba8227fb4d3a
> >
> >       
>