Feature request, but must be universallly accepted by ALL blanker authors

[Dave Howorth]

On Fri, 2 Oct 2020 23:11:55 -0400
Gene Heskett <gheskett at shentel.net> wrote:

> On Friday 02 October 2020 19:55:53 Aaron Plattner wrote:
> 
> > On 10/2/20 1:17 PM, Dan Arena wrote:  
> > > Gene,
> > >
> > > Following up more about xfce4, you should be able to go into their
> > > Settings Manager and you can turn off the Screensaver and uncheck
> > > Power Management under the Advanced tab. You will still want to
> > > add the lines I mentioned before into /etc/X11/xorg.conf to
> > > prevent the screen from going blank though.
> > >
> > > I also think it would be a useful feature for LinuxCNC to include
> > > an option where it itself can prevent screensavers. This would
> > > not be too hard for them to do, see
> > > https://stackoverflow.com/a/31504731/1941627
> > >
> > > A friend also just brought up a good point... do these machines
> > > not have a physical emergency stop button? It seems like with
> > > them being as dangerous as you say they are, they should. I know
> > > the couple mills I have seen do.  
> >
> > I agree with this. There are so many things that could go wrong
> > between the keyboard and software commanding the machine to stop
> > (swapping prevents something from getting scheduled, interrupt storm
> > from a rogue device delays processing, etc.). If this is really a
> > safety critical feature then everything in the system along this
> > path needs to have realtime guarantees, redundancy, and follow
> > something like MISRA coding standards.
> >
> > It would be *way* easier and cheaper to put a big red stop button on
> > the machine itself, and bypass this problem of screen locking
> > programs entirely.
> >
> > I would not recommend relying on the computer for this.  
> 
> This is quite true, and if it can't be fixed, I will be forced to
> install a smash it switch that interrupts machine power.  But I've
> some pretty high cap supplies that can keep it moving for several
> seconds after the switch has been fisted.  A software e-stop OTOH can
> stop it dead in the water in a very few milliseconds.

That sounds trivial to fix. Have the red stop button operate relays
that interrupt the circuits exactly where the software would.

> 5 maybe. The
> diff might be 50 bucks worth of smashed tooling for me.  And $2000+
> for a similar screwup at Toyota, who carves their lease only high
> output TRO engines for the racers with this same SW. Or were, they've
> taken down the youtube video as it was showing things they didn't
> want the joe six-packs copying.
> 
> 
> Thanks Aaron.
> >  
> > > I would also take this issue up with the LinuxCNC community. Is it
> > > supposed to work like that? Does a new install from the LinuxCNC
> > > "Install DVD" behave the same?  
> 
> At the instant yes, Andy has an install patched and running, and if
> it's still working in the morning he'll respin the install iso
> tomorrow. But his patch is not working for me, yet.
> 
> > > Thanks,
> > > Dan  
> 
> 
> Cheers, Gene Heskett