LinuxCNC on Debian Stretch

Pretty sure that no one is working as a RTAI kernel for LinuxCNC / Stretch

RTAI is still better for software step systems in most cases, though Preempt-RT can be very good on faster hardware.

Where external hardware does step generation, PWM generation,encoder counting etc RTAI doesn't really have
any advantages over Preempt-RT and is significantly harder to support

Just did a clean install of Debian 9 xfce using live edition three different times. Tried adding buildbot repo and ran into a mess. When adding key with;
sudo apt-key adv --keyserver hkp://keys.gnupg.net --recv-key E0EE663E
I get error;
gpg: keyserver receive failed: no dirmngr
so I did
sudo apt-get install dirmngr
and tried again
sudo apt-key adv --keyserver hkp://keys.gnupg.net --recv-key E0EE663E
and got error;
gpg: ketserver receive failed: Server indicated a failure
Tried to find a cure on Web with no luck, also tried it with Debian Cinnamon Live edition same failed twice same results

Tim

TIm-
LIke you, I installed Stretch. I then added the rt kernel. I put in linuxcnc-uspace, but not from the buildbot. Here's what I did, in case it helps.

I did get it all working.

Just for shits and giggles I gave the new Stretch ISO a whirl on an old P4 system, and I actually got better latency score numbers than I had been seeing with the Wheezy RTAI ISO. (Not great, but possibly usable numbers).

Monday morning I want to try plugging that HD into another old P4 system with an ISA card, and see if it works. That system has been running Lucid fine for a long time, but I can't get the Wheezy ISO to work at all on that machine.

Thanks for the info just finished up install with ISO mentioned in previous post only thing I did different was install network card drivers during install,(proprietary Intel drivers). The ISO gives me LCNC ver 2.7.10 will have to do for now wanted Master Branch 2.8. What version did you end up with, with your method? I tried to add build-bot key on this install also but it failed the same way as I mentioned in other post. By the way I helped you a little get started with LCNC a couple of years ago. How is that lath running on that little computer. Also if you could email me so I have your contact info again I lost yours, if you still have mine. I am not working in Kansas City now back in Michigan.

Thanks Mr Kennedy
Tim March

Since this resource has been made available I have tried and tested every edition to the current version 7.
Without failure to this date, why mess with a struggle when there is no need to?
I too was installing from here, there and everywhere, adding and deleting as was my want.
The latest version 7 has even picked up mt wifi card which until now I always had to install separately.
I would recommend this route above all at the moment.
Still not so keen on the xfce DE and all the other stuff that comes with it but that is only personal preference and soon changed.

www.linuxcnc.org/testing-stretch-amd64-rtpreempt/

Tim-
I have the following versions:
Debian 4.11.6-1 (i386)
Kernel 4.11.0-1-rt-686-pae
LinuxCNC 1.2.7.9
Gmoccapy 1.5.7

I'm getting really good latency times. The new 4.11 RT kernel works a little better than the 4.9 that I was using. I'm getting latencies around 2,500 average and infrequent peaks of 15,000.

I was getting occasional latency spikes of over 1,000,000 that played havoc with LinuxCNC. I had to do three things to address this:
Change GRUB to boot with isocpus=1
BIOS - Disable Intel Dynamic Power Technology
BIOS - Set the fan speed to constant instead of adaptive. (Thanks to arceye for mentioning this in a post. I had never seen it anywhere else.)

I have one additional problem that I think I understand. If I load up LinuxCNC right after booting, I may get a latency spike and error message. I don't get this (yet) it I wait a couple of minutes for Linux to do whatever it does after it first boots. I just got this working last week, so I'm still in testing mode. In any case, doing the three things above has improved the problem immensely.

Like you, I've had trouble with Intel network drivers. I've had to round up iwlwifi-7265D-23.ucode, -24, -25, and -26 driver files. With the latest Debain update, it now wants -27 and -28 drivers. (These can be found at github.com/NetBit73/NeteXt73_pakiety/tree/master/iwlwifi) I'll have to install those when I get a chance.

Todd wrote:

Just for shits and giggles I gave the new Stretch ISO a whirl on an old P4 system, and I actually got better latency score numbers than I had been seeing with the Wheezy RTAI ISO. (Not great, but possibly usable numbers).

Monday morning I want to try plugging that HD into another old P4 system with an ISA card, and see if it works. That system has been running Lucid fine for a long time, but I can't get the Wheezy ISO to work at all on that machine.

This was a dismal failure, for me The machine (an old 2.8GHz P4 with ISA slots 1G ram) performed pathetically with the HD I set up on another old 2.4GHz P4. The ISA slotted machine would not even plot lines on the latency plot screen, everything was either over or under runs. By comparison the slower machine I setup the disk on, was showing max latency of about 35us. So I plugged the Lucid disk back in. I wish I understood why that old machine refuses to work with any of the newer kernels.

Since this resource has been made available I have tried and tested every edition to the current version 7.
Without failure to this date, why mess with a struggle when there is no need to?
I too was installing from here, there and everywhere, adding and deleting as was my want.
The latest version 7 has even picked up mt wifi card which until now I always had to install separately.
I would recommend this route above all at the moment.
Still not so keen on the xfce DE and all the other stuff that comes with it but that is only personal preference and soon changed.

www.linuxcnc.org/testing-stretch-amd64-rtpreempt/

Looks like it has been taken down, didn't last long did it?

Nothing so nefarious.... The linuxcnc buildbot server seems to be down currently. (Where the ISO was hosted)

grump wrote:

Looks like it has been taken down, didn't last long did it?