Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Wed, 2 Sep 2009 09:48:46 -0500

Hi Peter,

On Wednesday 02 September 2009 06:21:31 Dr. Peter Zumbruch wrote:
> I am looking for documentation of aSub which I cannot find in the
> neither in the WIKI nor elsewhere.
>
> Are there differences or can one just rely on the genSub documentation
> of Andy Foster?

There are a few differences, but in most cases you should just be able to 
replace genSub with aSub in the relevent .db and .c files and the result 
usually Just Works{TM}.  The differences as described in the release notes 
are:

    * The fields UFA..UFU, UFVA..UFVU, TOVA..TOVU and VERS have been removed.
    * The INPA..INPU and OUTA..OUTU link fields can now be changed at runtime.
    * A new set of fields NEA..NEU and NEVA..NEVU have been added which hold 
the current element count for the associated input and ouput fields. These 
count fields ensure that putting an array to the A..U or VALA..VALU fields 
cannot permanently shorten the number of elements that the array fields can 
hold.
    * The default value for the FTA..FTU and FTVA..FTVU fields has been 
changed from "STRING" to "DOUBLE", to reduce the memory footprint of unneeded 
fields.
    * aSub subroutines can be asynchronous, using the usual method of setting 
prec->pact to TRUE before returning and arranging for the record's process() 
routine to be called to signal completion. The output links are not written 
until the asynchronous completion callback, and input links are not read at 
asnychronous completion.

If someone is interested in importing Andy's documentation into the Wiki and 
modifying it for the aSub I think quite a few people would be grateful.

- Andrew
-- 
The best FOSS code is written to be read by other humans -- Harold Welte

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System