Experimental Physics and
Industrial Control System

Angus Gratton <[email protected]> · Tue, 27 Jul 2010 09:00:11 +1000

Thanks Ralph & Mark.

On Mon, 2010-07-26 at 09:40 -0400, Ralph Lange wrote:
> That way an ao with "...@5V BIP" and EGUF/EGUL = +/- 5 will convert from 
> "output voltage" to the 16-bit integer your card needs, while setting 
> EGUF/EGUL to something else will do the linear conversion from that 
> "something else" range to your raw value. This is the whole point of 
> having EGUF/EGUL/EGU as design fields - 

OK, sounds great. It's possible to have device support set the defaults
though, right? To avoid the designer having to repeat themselves in each
record if they just want the default case?

> .
> 
> Please do not write your device support starting from scratch. Copy the 
> device support for a device that is similar to yours

Yes, I understand. I've been working from the well documented minimal
example given in this presentation:

http://www.aps.anl.gov/epics/meetings/2009-07/talks/em_WritingEPICSDrivers.ppt

Outside of there, I've downloaded a few device support sources and
looked at them but to be honest it's hard to tell what is legacy and
what is a good example - lots of the sources haven't been touched in
many years, some of them do things like combine device support & the
driver into the same source, which I understand is no longer
recommended. Which is why I thought I'd ask to be sure, because I'm not
yet experienced enough to tell the difference between a good example and
a bad one.

Regards,

Angus

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System