Re: waveform changes using subArray

[Andrew Johnson <anj@aps.anl.gov>]

Hi Hinko,

You should also be able to replace the waveform record with an aSub record and 
implement the sub-array replacement part in C code, which would need fewer 
records on the IOC and is probably slightly more efficient, but will take more 
development work to implement.

- Andrew

On 2012-09-14 Hinko Kocevar wrote:
> Ned, Tim thank you for suggestions. We'll try out solution ASAP.
> 
> Best Regards,
> Hinko
> 
> On 09/13/2012 06:33 PM, Tim Mooney wrote:
> > Hinko,
> >
> > You could do this with the acalcout (array calcout) record in the calc
> > module. (http://www.aps.anl.gov/bcda/synApps/calc/aCalcoutRecord.html) If
> > .BB is the M-element replacement array, you can read the waveform into
> > the .AA field, overwrite with M elements from .BB, beginning at index N,
> > and write the result back to the waveform record, by configuring the
> > record like this:
> >
> > .A = M
> > .B = N
> > .INAA = "waveform.VAL NPP"
> > .CALC = "AA[0,B-1]+(BB[0,A-1]>>B)+(AA[A+B,-1]>>A+B)"
> > .OUT = "waveform.VAL PP"
> >
> > Tim
> >
> > ----- Original Message -----
> > From: "Hinko Kocevar" <hinko.kocevar@i-tech.si>
> > To: "Tech Talk" <tech-talk@aps.anl.gov>
> > Sent: Thursday, September 13, 2012 6:59:05 AM
> > Subject: waveform changes using subArray
> >
> > Hi,
> >
> > We are trying to support a modification of long array (i.e. more than
> > 500 integer values) seen as a waveform in EPICS IOC. Lets say that it is
> > possible and valid for user to change only one or two values from this
> > array. By using waveform user needs to get all 500 integers locate the
> > one she wants to change, do the modification, store complete array back.
> > Using subArray to make a "window" into waveform sounded like a good
> > solution, but as I just read in the docs, subArray does not support
> > value writing back to the waveform.
> >
> > Can this be done in some other manner? The goal here would be to allow
> > user to get/see/change/set only the part of waveform, that shes
> > interested in.
> >
> > Thank you!
> >
> > Hinko
-- 
Never interrupt your enemy when he is making a mistake.
-- Napoleon Bonaparte