On Sunday 29 September 2013 19:56:50 John Kasunich did opine:
> On Sun, Sep 29, 2013, at 06:45 PM, Chris Morley wrote:
> > I mean if we wanted we could only have one spindle velocity output pin
> > instead of fwd,rev,rps_out,rpm_out, spindle_on,brake_on,vel_cmd pins
> > etc. It would just require the user to add half a dozen components to
> > make them all work.
>
> Actually two are needed: spindle_on and velocity_command
>
> All the others can be derived from those. IMO, two are needed because
> I don't want to rule out the possibility of "on but at zero speed". For
> example, during rigid tapping the velocity command passes through
> zero.
>
> As a specific example of why NOT to put all that in motion, consider
> "brake on". That is there because it was present in EMC1. But what
> are the actual requirements of a given system? Maybe they want a
> short delay before applying the mechanical brake? Maybe a delay
> when the brake is removed, before starting the spindle drive? There
> is a pretty good chance that the existing brake pin won't work for
> many users. Better to get that logic out of motion and let the users
> do what they need.
>
We/I have. So while I'm still rowing with a toothpick here, I do not see
the need to further the complexity of motion. The tools to build the 3
level suicide braking system for my lathe are right there in hal today.
> I like Steve Stalling's suggestion to make a HAL component that
> generates the "bundle of signals" that you listed above. Such a
> component would be simple to load, and would compartmentalize
> the spindle logic separately from the rest of motion. A user could
> easily look at the component and decide if it meets his needs or
> if he needs to do further customization, either by adding more HAL
> components or by making a custom version of the "spindle-bundle"
> comp.
Cheers, Gene
--
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