Experimental Physics and
Industrial Control System

Eric Bjorklund <[email protected]> · Wed, 3 May 2000 10:39:56 -0600

Marty,

Thanks for clarifying this.

>
>What causes the confusion is that old database access, which is what CA uses,
>only knows how to handle the maximum number of elements.
>
>The correct behavior is that  cvt_dbaddr sets no_elements = NELM, ie the
>size of
>the allocated array and get_array_info returns NORD, i.e. the current actual
>number of elements.
>

>
>My suggestion is to do the following.
>
>Define the DSET to have one additional method, call it init_record_pass0, and
>then let the record support init_record call it during pass 0. The device
>support must allocate storage for the array when init_record_pass0 is called.
>

My question here is that since we're mucking with the aao record anyway,
wouldn't
it be better to have the record support module allocate the buffer during
pass 0
based on NELM and FTVL?  Then the only device support change would be to
*remove*
the buffer allocation code.  We would, of course, have to be sure that FTVL was
set correctly in each of the records -- for me that would be no problem (and I
suspect it wouldn't be for Timor either at this point).

Eric Bj.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System