Re: Problem of NORD field in waveform (R3.14.4)

[Marty Kraimer <mrk@aps.anl.gov>]

The waveform record support implements put_array_info as follows (note 
how it handles nord):

static long put_array_info(paddr,nNew)
   struct dbAddr *paddr;
   long          nNew;
{
   struct waveformRecord       *pwf=(struct waveformRecord 
*)paddr->precord;

   pwf->nord = nNew;
   if(pwf->nord > pwf->nelm) pwf->nord = pwf->nelm;
   return(0);
}

If you call dbPut instead of writing directly to the waveform record 
dbPut will call put_array_info.

If you really want to write directly to the array in a record do the 
following:

1) MAKE sure the link is a DB_LINK.
2)  Get the value of DBADDR *pdbAddr
3) Check the following:
    pdbAddr->dbr_field_type is the type you expect, e.g. DBF_DOUBLE
    long max_elements = pdbAddr->no_elements;
    struct rset *prset = pdbAddr->precord->rset;
   if(!prset->get_array_info || !prset->put_array_info) ERROR
4) Write the array as follows:
   long  n, no_elements,offset

   status = prset->get_array_info(pdbAddr,&no_elements,&offset)
   if(!status) error    
   Make sure n< max_elements
   double *pto = pdbAddr->pfield;
   for(i=0; i<n; i++) *pto++ = *pfrom++;
   status = prset->put_array_info(pdbAddr,n);
   if(!status)error

This will work as long as the array is not a circular buffer. If it does 
then life gets more complicated.

Kim, Kukhee wrote:

> Dear ALL;
>
> I am playing with waveform record on the R3.14.4.  A subroutine record puts values to a waveform record directly, but whole reading values of the waveform were always â0â when I tried âcagetâ.  So, I checked out the NORD field in the waveform record. It was always â0â.  I guess, it is supposed to have same value with NELM field.
> So, I made small cheating as the following.  It is a part of subroutine record to set NORD field to same value with NELM field.
> ãããã
> 	DBADDR *pdbAddrLinkA = dbGetPdbAddrFromLink(&prec->inpa);
> ããããDBADDR *pdbAddrLinkB = dbGetPdbAddrFromLink(&prec->inpb);
> 	long   no_elements   = pdbAddrLinkA->no_elements;
> ããããwaveformRecord  *precord;
>
> ããããprecord = (waveformRecord*)pdbAddrLinkA->precord;
> ããããprecord->nord=no_elements; 
> ããããprecord = (waveformRecord*)pdbAddrLinkB->precord;
> ããããprecord->nord=no_elements;
>
> And then, I can read waveform normally.
> I would like to know, what cause this problem?
>
> Thank you.
> -------------------------------
> Kukhee Kim
> Instrument & Control, KSTAR
> Korea Basic Science Institute
> 52 Yeoeun-dong, Yusung-gu, Daejeon 305-333
> Korea
> Email: kimkh@kbsi.re.kr
> Tel: +82 42 870 1616     Fax: +82 42 870 1609      Cell: +82 17 513 484
> ã
>
>
>
>