Re: Convertion for asynFloat64

[Benoit <benpaka.spam@gmail.com>]

Thanks for the intersting suggestion... I did try both (writing in OCAL and in A) and it is working!

But I think this is too much "hacking" and I am wondering of the bad consequence of this action in the future... 

I have decided to finally keep with a temporary record which is more "standard" use.

Cheers,

Benoit

--
Benoit RAT
www.neub.co.nr

On Fri, Nov 22, 2013 at 6:39 PM, J. Lewis Muir <jlmuir@imca-cat.org> wrote:

On 11/22/13 11:16 AM, Andrew Johnson wrote:
> Hi Lewis,
>
> On 11/22/2013 10:53 AM, J. Lewis Muir wrote:
>> EPICS Base developers, it would be great if a write to the calcout
>> VAL field did trigger record processing.  But maybe there's a reason
>> why it doesn't?
>
> I didn't design that record type, but why would you want to be able
> to write a value to a field when that value is normally going to be
> immediately overwritten when the record processes?

Hi, Andrew.

My only reason is just from a PV "API" standpoint.  Lots of people leave
off the ".VAL" suffix from the PV name, so in this case, they wouldn't
be able to do that unless the VAL field was pp(TRUE).

> Note that the pp(TRUE) setting only applies when doing a put through
> CA, a database link can directly control whether processing happens or
> not.

Interesting.  Thanks for pointing that out; I didn't know that.

> In this particular case you're getting clever with the record so I do
> understand the request, but the ability to access the VAL field from a
> Calc _expression_ is a lot newer than the calcout record. Note also that
> in an OCAL _expression_, VAL actually returns the last value from the
> OVAL field, not the VAL field, so setting OCAL to "1000 * VAL" would
> not do the scaling of the VAL field that Benoit wants it to do.

Right, that's what I said when I wrote, "So maybe you could write to
that [the OVAL field], and use the OCAL _expression_ and set DOPT to 'Use

OCAL' and get the behavior you want by writing to OVAL instead of VAL
(albeit confusing)?"

Thanks,

Lewis