Re: monitors on array variables

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

Same result. I had it set to a big number to handle the full 384*4096 array of spectra for all the channels (this is for Maia-II). Anyhow, camonitor would complain if that were the case.

Pete.

---

From: Mark Rivers <rivers@cars.uchicago.edu>
Sent: Wednesday, March 18, 2020 3:02 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

 

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