Experimental Physics and
Industrial Control System

Korhonen Timo <[email protected]> · Wed, 3 May 2000 16:30:09 +0200 (MEST)

Eric,

thank you for your reply and sorry for my late response.

On Mon, 1 May 2000, Eric Bjorklund wrote:

> So, in response to my original questions:
> 
> > o Shouldn't "put_array_info" be updating the NORD field instead of the
> >   NELM field? (if so, it means we should probably change the code in
> >   devAaoCamac.c as well).
> 
> Yes, I believe it should.
> 
> > o What is the correct value, NELM (the capacity of the record) or NORD
> >   (the number of points actually written) to return from "cvt_dbaddr"
> >   and "get_array_info"?
> 
> For an output record, these routines should probably return NELM (the capacity
> of the record) rather than NORD (the size of the last write).  I believe that
> is how the aao record works now.

I thought so, too. But looking at the waveform record, the get_array_info
returns NORD and cvt_dbaddr returns NELM (in a dbAddr struct). 

The Application Developers guide says for get_array_info: "This routine
returns the current number of elements and the offset of the first value
of the array." For cvt_dbaddr: "This routine can change any combination of 
the dbAddr fields...". What should be returned in the dbAddr->no_elements 
is not specified, but to me it looks like it should be NELM.

What should the correct behaviour be?

> As I understand things now, record support needs to be the one allocating the
> buffer space since the device-support record_initialization routine only
> gets called during pass=1.  This particular bug has not been a problem for
> us (yet), but I can see where it could be.  I'd be interested in seeing your
> solution Marty.

Me too!

> We have a grand total of two (2) device support routines for the aao record,
> so it would be no big deal for us to change the way it works.  I'd vote to
> go for it -- particularly since the init problem could be pretty nasty.

I would prefer that, too. I have one device support that I started
writing last week.

> The comments on the aaoRecord.c code indicate it is from Jefferson Lab
> (the facility formerly known as CEBAF).  So I would guess that is where
> the most investment in aao records resides.  Any comments from that front?

I would also be interested...

best regards,
		Timo

Timo Korhonen  PSI (Paul Scherrer Institut), SLS 
               CH-5232 Villigen PSI 
               tel + 41- 56 3103262  fax + 41 - 56 310 3151 
e-mail:	       [email protected]

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System