Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Tue, 22 Jul 2008 13:46:05 -0500

On Monday 21 July 2008 05:13:21 Rowland, J (James) wrote:
>
> For the inverse subarray record, is there a nice way to create 1000s of
> input links (AAA->ZZZ is too many to be practical) or is the CA client
> library the interface to use? Is it possible (or wise) to create dblink
> structures outside the db parser so that the array of links can have the
> usual attributes?

I think the overhead of creating large numbers of links is likely to be a 
waste, and I'm not sure that you'd be able to do it outside of a regular 
record anyway.

I suggest looking at the vxWorks global symbol device support symb/devSymb 
(see http://www.aps.anl.gov/epics/modules/soft/devSymb.html for docs, 
download from http://www.aps.anl.gov/epics/download/modules/index.php ) which 
allows you to point individual input and output records at indexed elements 
of a named in-memory array.  You can also get at the named arrays from state 
programs or subroutine record subs, but you do have to be a little careful 
about synchronization (using subroutine records to sequence the calculations 
takes care of that).

We used this technique for the Gemini primary mirror support calculations, 
which used matrices up to about about 180x180 IIRC.

- Andrew
-- 
Talk is cheap. Show me the code. -- Linus Torvalds

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System