Re: aiRecord conversion

[Eric Norum <wenorum@lbl.gov>]

On Aug 28, 2012, at 8:55 AM, Ralph Lange <Ralph.Lange@gmx.de> wrote:

On Tue Aug 28 2012 17:31:37 GMT+0200 (CEST), Eric Norum <eric@norum.ca> wrote:

[...]

NOTE TO WHOMEVER IS MAINTAINING http://www.aps.anl.gov/epics/EpicsDocumentation/AppDevManuals/RecordRef/Recordref-8.html#HEADING8-0    ----  IT NEEDS TO BE FIXED!

Eric,

This is the prehistoric version of the Record Reference Manual, before it was wikified in 2005.
It describes the 3.13 linear conversion correctly.

Really?   Hmm…..

Let's have a look at the R3.13.10 code:

static void convert(aiRecord *pai)

{

    double val;

    val = (double)pai->rval + (double)pai->roff;

    /* adjust slope and offset */

    if(pai->aslo!=0.0) val*=pai->aslo;

    val+=pai->aoff;

    /* convert raw to engineering units and signal units */

    if(pai->linr == menuConvertNO_CONVERSION) {

        ; /* do nothing*/

    }

    else if(pai->linr == menuConvertLINEAR) {

        val = (val * pai->eslo) + pai->eoff;

    }

Looks just like the R3.14 (and R3.15 code)……

*However* -- the R3.12 code does use EGUL -- but this is over 15 years old.

All links on the EPICS web site point to the current wiki version.

I honestly don't think anyone should invest time into "fixing" history.

Maybe, but the fact that it seems to be showing up as the top google hit is a matter of concern, I think.

Proof by example -- it's clearly already tripped up one new developer.

I really (note, no yelling this time  :-) ) think that the ancient documentation should be expunged.

-- 
Eric Norum
wenorum@lbl.gov