Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Fri, 10 Feb 2012 15:24:52 -0600

Hi Mark,

On 2012-02-10 Mark Rivers wrote:
> Questions:
> 
> - Did these fields ever exist?

Probably at one time, but as Michael has shown there is no record of them in 
the revision control history so they were removed before we started using CVS 
in about 1994.

> - Should they be added?
> 
> - If so, then while we are adding these fields are there others we should
>  also add that would not break backward compatibility?

How about adding some generic parameter fields instead: A double field for the 
parameter value and an associated string field that the device support can set 
it its init_record() routine to describe it.  I wonder if they couldn't just 
be separate records though, how about using ao, bo, longout, mbbo and 
stringout records to set parameters for the waveform acquisition?

> Here are is one that I can think of:
> 
> NUSE: The number of elements in the waveform to actually use.  Must be
>  <=NELM.

Is this meant to tell input device support how many elements to try and read?

> Also, the record does not post monitors on the BUSY or NORD fields.  Should
> this be the responsibility of device support, or does that code belong in
> the record?

Both those fields are currently documented as Rec Proc Monitor = NO, but that 
doesn't mean we can't change them.  The record code only looks at BUSY in one 
place and never sets it itself; I think if device support sets it and wants 
the world to know about changes it should post its own monitors on BUSY.

There are a couple of places where the record code sets NORD: after an array 
put, and in simulation mode.  I could accept that the record support should 
post monitors when it sets NORD, but it should be the device support's 
responsibility when it does so.  This would be a 3.15 change.

- Andrew
-- 
Optimization is the process of taking something that works and
replacing it with something that almost works, but costs less.
-- Roger Needham

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System