Experimental Physics and
Industrial Control System

Jim Thomas <[email protected]> · Wed, 13 Aug 2008 09:27:21 -1000

>>>>> "Mark" == Mark Rivers <[email protected]> writes:
>>>>> "Matthew" == Pearson, MR (Matthew) <[email protected]> wrote:

 Matthew> It is arguably more useful to have a 'homed' status, rather than
 Matthew> 'at home'.

 Mark> I think we should stick with the "at home" meaning.  Many (most?)
 Mark> controllers don't have the concept of "homed" but they do have the
 Mark> concept of "at home".

I vote for having a "homed".  How does one tell if the position is known
otherwise?  Our "lost" == ~"homed" makes for an easy check.

 Matthew> Especially since the 'at home' status can be inferred from the
 Matthew> position (once it is homed of course).

 Mark> I don't think you can infer "at home" from the position.  What if the
 Mark> motor is a stepper with no encoder and it lost steps sometime after
 Mark> being homed?  It might not really be at home when the position says it
 Mark> is.

Agreed.  But then the system is broke anyway, so who cares?

$0.02
Jim

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System