Experimental Physics and
Industrial Control System

On Tue Aug 28 2012 15:28:34 GMT+0200 (CEST), Bruno Seiva Martins <[email protected]> wrote:

Rectifying:

   epicsFloat64 div;

   pao->eguf = 10.0;

   pao->egul = (type == LCN12BMP || type == LCN16BMP) ? 0.0 : -10.0;

   div = (type == LCN12BMP || type == LCN12BBP) ? 4095.0 : 65535.0;

   pao->hopr = pao->eguf; 

   pao->lopr = pao->egul; 

   pao->eslo = ((pao->eguf) - (pao->egul)) / div;

Bruno Seiva Martins

Another comment:

The linear conversion mechanism is intended to convert the digitized value into the final engineering units.

You might want to use your A/D converter for signals that correspond to positions [mm], pressures [mbar], or temperatures [C].
In those cases, the database designer will set EGU, EGUL and EGUF to e.g. "mm", -5 and 25, meaning that -10V are equivalent to -5mm, and +10V are equivalent to +25mm. To limit the range that is shown in the GUI, the designer might also want to set e.g. LOPR to -2 and HOPR to +2, so that graphs and meters show the "interesting" range, -2mm to +2mm.

To have this work correctly, setting EGUF, EGUL, HOPR and LOPR in your device support may actually not be a good idea.
Normally, I would just set ESLO and EOFF.

Cheers,
~Ralph