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

Gene Heskett gheskett at shentel.net
Sat Oct 3 03:11:55 UTC 2020

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. 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
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Genes Web page <http://geneslinuxbox.net:6309/gene>

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