New computer for linuxcnc

As you advised the on-board video chipset does have better results,without the video card drivers installed the latency is sligtly better but the graphics are worse than with the on-board video, whith drivers installed i get latency spikes up to 30000

Today i also had a go with Ubuntu Pangolin Precise 12.04 and the xenomai realtime kernel, i get worse latency results with and without the video card

graphically is much better, but in latency the results are very bad.

I really tough the new realtime was better, i should try harder with maybe isolcpu=1 but it works so good on 10.04

Hi

xenomai works, but I have always got worse jitter figures with it than rtai
If you have servos or hardware stepgens that probably does not matter, but for software stepper setups, it was too high on my machines

Try these packages on 12.04.
I tested Sebs first ones on a 3.4.xx kernel and they worked fine
highlab.com/~seb/linuxcnc/rtai-for-3.5-prerelease/

I only achieved better figures than these, with my own homebrew 3.5.7-rtai kernel, which I had tuned to the computer and was ruthless with all power management etc

regards

PS Because it is RTAI, the isolcpus kernel parameter should do more with this kernel too

which package should i install all of them?

You just need

linux-image
linux-headers
rtai-modules

There are 2 rtai-modules, so I assume the one with ubuntu in the file name, don't know what the difference is, that has changed since i last looked.

Just one more question, should i build linuxcnc from the source for xenomai or from the normal 2.5 source?


EDIT:

i builded from the linuxcnc xenomai compatible source, it works now with the new rtai on ubuntu 12.04

i followed this

wiki.linuxcnc.org/cgi-bin/wiki.pl?NewRTInstall

The jitter is much lower than with xenomai, i had to use isolcpu=1 tough to get low jitter, now it works fine

grandixximo wrote:

i builded from the linuxcnc xenomai compatible source, it works now with the new rtai on ubuntu 12.04

i followed this

wiki.linuxcnc.org/cgi-bin/wiki.pl?NewRTInstall

The jitter is much lower than with xenomai, i had to use isolcpu=1 tough to get low jitter, now it works fine

That is what I was going to suggest.

I have also built a single processor version of 3.5.7-rtai and installed on my workshop machines

I am actually getting lower latency heavily loaded running this on Wheezy (7K) on P4 2.4GHz than I was running 8.04 on them (9K)

We live in interesting times

regards

My mill has been down for about a year looking for a limit switch. Finally discovered that Allied Electronics has an excellent selection of Honeywell micro switches.

Installed the new switch last night, and found that my PC (old D525) is dead.

Looking on Newegg this morning, and found these two items:

N82E16819116405 cpu

N82E16813128537 motherboard

But I still need an additional parport card. What card do I need with this motherboard?

Thanks

Tom

Hi

It appears to have 1 parport plus 2 PCI and 1 PCIe slots

You can just use a netMos (Moschip) based PCI card (9845 9865 9901) unless you need to use EPP mode in which case their implementation is flakey and
the Oxsemi (PLXTech now) OX16PCI954 is recommended by PCW I think for FPGA cards.

regards